Design, fabrication, and test of a steel spar wind turbine blade

NASA Technical Reports Server (NTRS)

Sullivan, T. L.; Sirocky, P. J., Jr.; Viterna, L. A.

1979-01-01

The design and fabrication of wind turbine blades based on 60 foot steel spars are discussed. Performance and blade load information is given and compared to analytical prediction. In addition, performance is compared to that of the original MOD-O aluminum blades. Costs for building the two blades are given, and a projection is made for the cost in mass production. Design improvements to reduce weight and improve fatigue life are suggested.

Design and fabrication of composite blades for the Mod-1 wind turbine generator

NASA Technical Reports Server (NTRS)

Batesole, W. R.; Gunsallus, C. T.

1981-01-01

The design, tooling, fabrication, quality control, and testing phases carried out to date, as well as testing still planned are described. Differences from the 150 foot blade which were introduced for cost and manufacturing improvement purposes are discussed as well as the lightning protection system installed in the blades. Actual costs and manhours expended for Blade No. 2 are provided as a base, along with a projection of costs for the blade in production.

In-service inspection of steam turbine blades without disassembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinhart, E.R.

1987-01-01

Loss of utility plant availability as a result of failure-causing cracks in steam turbine blades makes early detection of this problem critical. An Electric Power Research Institute survey, conducted as part of project RP 1266-24, indicated that 72% of turbine blade failures in fossil power plants occur in low-pressure (LP) turbines with half of all blade failures occurring in the last two blade stages (L-0 and L-1 rows). Failures are generally associated with blade tailing edges and root areas. Project RP 1266-24 also found that 79% of the blade problems in LP turbines were cracks. A turbine design of particularmore » concern has been the Westinghouse Building Block (B.B.) 73. Reinhart and Associates has successfully inspected seven in-place B.B. 73 units for six utilities during the past 3 yr, as well as several disassembled turbines of other manufacturers and designs. These examinations consisted of visual and eddy-current examinations of the blade roots and trailing edges. The in-place inspections were performed using prototype manipulation devices to gain access to the blades through the hand holes. The only disassembly required to gain access for the examinations was the removal of the man-way covers on the main shell and the hand-hole covers on the outer cylinder covering the L-0 and L-1 blade rows.« less

Effect of Cricoid Pressure on Laryngeal View During Macintosh, McGrath MAC X-Blade and GlideScope Video Laryngoscopies

PubMed Central

Arslan, Zehra İpek; Solak, Mine

2017-01-01

Objective Cricoid pressure is useful in fasted patients requiring emergency intubation. We compared the effect of cricoid pressure on laryngeal view during Macintosh, McGrath MAC X-Blade and GlideScope video laryngoscopy. Methods After obtaining approval from the Human Research Ethics Committee and written informed consent from patients, we enrolled 120 patients (American Society of Anesthesiologists I–II, age 18–65 years) undergoing elective surgery that required endotracheal intubation in this prospective randomised study. Patients were divided into three groups (Macintosh, McGrath MAC X-Blade and GlideScope). Results Demographic and airway variables were similar in the groups. Cormack-Lehane grades were improved or unchanged on using cricoid pressure in Macintosh and McGrath MAC X-Blade groups. However, laryngeal views worsened in 12 patients (30%), remained unchanged in 26 patients (65%) and improved in 2 patients (5%) in the GlideScope group (p<0.001). Insertion and intubation times for Macintosh and McGrath MAC X-Blade video laryngoscopes were similar. Insertion times for GlideScope and Macintosh video laryngoscopes were similar, but were longer than those for the McGrath MAC X-Blade video laryngoscope (p=0.02). Tracheal intubation took longer with the GlideScope video laryngoscope than with the other devices (p<0.001 and p=0.003). Mean arterial pressures after insertion increased significantly in Macintosh and GlideScope groups (p=0.004 and p=0.001, respectively) compared with post-induction values. Heart rates increased after insertion in all three groups compared with post-induction values (p<0.001). Need for optimisation manoeuvres and postoperative minor complications were comparable in all three groups. Conclusion Although all three devices are useful for normal or difficult intubation, cricoid pressure improved Cormack-Lehane grades of Macintosh and McGrath MAC X-Blade video laryngoscopes but statistically significantly worsened that of the GlideScope video laryngoscope. PMID:29359076

A Highly Resolved Large-Eddy Simulation of a Wind Turbine using an Actuator Line Model with Optimal Body Force Projection

DOE PAGES

Martinez-Tossas, Luis A.; Churchfield, Matthew J.; Meneveau, Charles

2016-10-03

When representing the blade aerodynamics with rotating actuator lines, the computed forces have to be projected back to the CFD flow field as a volumetric body force. That has been done in the past with a geometrically simple uniform three-dimensional Gaussian at each point along the blade. Here, we argue that the body force can be shaped in a way that better predicts the blade local flow field, the blade load distribution, and the formation of the tip/root vortices. In previous work, we have determined the optimal scales of circular and elliptical Gaussian kernels that best reproduce the local flowmore » field in two-dimensions. Lastly, in this work we extend the analysis and applications by considering the full three-dimensional blade to test our hypothesis in a highly resolved Large Eddy Simulation.« less

A Highly Resolved Large-Eddy Simulation of a Wind Turbine using an Actuator Line Model with Optimal Body Force Projection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez-Tossas, Luis A.; Churchfield, Matthew J.; Meneveau, Charles

When representing the blade aerodynamics with rotating actuator lines, the computed forces have to be projected back to the CFD flow field as a volumetric body force. That has been done in the past with a geometrically simple uniform three-dimensional Gaussian at each point along the blade. Here, we argue that the body force can be shaped in a way that better predicts the blade local flow field, the blade load distribution, and the formation of the tip/root vortices. In previous work, we have determined the optimal scales of circular and elliptical Gaussian kernels that best reproduce the local flowmore » field in two-dimensions. Lastly, in this work we extend the analysis and applications by considering the full three-dimensional blade to test our hypothesis in a highly resolved Large Eddy Simulation.« less

Stainless-Steel-Foam Structures Evaluated for Fan and Rotor Blades

NASA Technical Reports Server (NTRS)

Lerch, Bradley A.; Raj, Sai V.; Ghosn, Louis J.; Hebsur, Mohan G.; Cosgriff, Laura M.; Min, James B.; Holland, Frederic A., Jr.

2005-01-01

The goal of this project is to use a sandwich structure design, consisting of two stainlesssteel face sheets and a stainless-steel-foam core, to fabricate engine fan and propeller blades. Current fan blades are constructed either of polymer matrix composites (PMCs) or hollow titanium alloys. The PMC blades are expensive and have poor impact resistance on their leading edges, thereby requiring a metallic leading edge to satisfy the Federal Aviation Administration s impact requirements relating to bird strikes. Hollow titanium blades cost more to fabricate because of the intrinsically difficult fabrication issues associated with titanium alloys. However, both these current concepts produce acceptable lightweight fan blades.

Construction of the 18-meter wooden blade at Nibe-Molle B

NASA Technical Reports Server (NTRS)

Nielsen, P. C.

1982-01-01

The construction of an 18 m cantilevered wooden rotor blade for wind turbine-B at Nibe, Denmark is reported. The project is described and conclusions are made based on calculations and tests on the rotor blade. Details are given on choice of material, construction, attachments and fittings, stress problems and loads.

Georgia Tech Vertical Lift Research Center of Excellence

DTIC Science & Technology

2017-12-14

Technical Project Summaries Task 1.1 (GT-1): Next Generation VABS for More Realistic Modeling of Composite Blades ...Methodology for the Prediction of Rotor Blade Ice Formation and Shedding ..................................................................... 20...software disclosures and technology transfer efforts. Task 1.1 (GT-1): Next Generation VABS for More Realistic Modeling of Composite Blades PIs

Construction of the 18-meter wooden blade at Nibe-Molle B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, P.C.

The construction of an 18 m cantilevered wooden rotor blade for wind turbine-B at Nibe, Denmark is reported. The project is described and conclusions are made based on calculations and tests on the rotor blade. Details are given on choice of material, construction, attachments and fittings, stress problems and loads.

Construction of the 18-meter wooden blade at Nibe-Molle B

NASA Astrophysics Data System (ADS)

Nielsen, P. C.

1982-11-01

The construction of an 18 m cantilevered wooden rotor blade for wind turbine-B at Nibe, Denmark is reported. The project is described and conclusions are made based on calculations and tests on the rotor blade. Details are given on choice of material, construction, attachments and fittings, stress problems and loads.

Manufacturing Methods & Technology Project Execution Report. First Half CY 80

DTIC Science & Technology

1980-08-01

1 80 7371 INTEGRATED BLADE INSPECTION SYSTEM (IBIS) INSPECTION OF TURBINE ENGINE BLADES AND VANES NECESSITATES HIGH ACCURACY. THE EFFORT IS TIME...OPTICAL INSP OF PRINTED CIRCUIT BOARDS OPERATOR FATIGUE ALLOWS MANY BAD PCBSS TO PASS VISUAL INSPECTION . 29 PROJECTS ADDED IN 1ST HALF» CY80...2631 TITLED "CRITICAL ELECTROHAGNETIC INSPECTION PROBLEMS WITHIN THE ARMY." FUTURE STATUS WILL BE INCLUDED IN THE PROJECT STATUS FOR M 80 6350

Progress in the utilization of an oxide-dispersion-strengthened alloy for small engine turbine blades

NASA Technical Reports Server (NTRS)

Beatty, T. G.; Millan, P. P.

1984-01-01

The conventional means of improving gas turbine engine performance typically involves increasing the turbine inlet temperature; however, at these higher operational temperatures the high pressure turbine blades require air-cooling to maintain durability. Air-cooling imposes design, material, and economic constraints not only on the turbine blades but also on engine performance. The use of uncooled turbine blades at increased operating temperatures can offer significantly improved performance in small gas turbine engines. A program to demonstrate uncooled MA6000 high pressure turbine blades in a GTEC TFE731 turbofan engine is being conducted. The project goals include demonstration of the advantages of using uncooled MA6000 turbine blades as compared with cast directionally solidified MAR-M 247 blades.

Unsteady flow and dynamic response analyses for helicopter rotor blades

NASA Technical Reports Server (NTRS)

Bratanow, T.

1979-01-01

Research is presented on helicopter rotor blade vibration and on two and three dimensional analyses of unsteady incompressible viscous flow past oscillating helicopter rotor blades. A summary is presented of the two international research collaborations which resulted from the NASA project: the collaboration under the auspices of NATO between the University of Wisconsin-Milwaukee, University of Brussels, Belgium and the Aerodynamics Research Establishment in Goettingen, West Germany, and the collaboration under the auspices of the National Science Foundation between UWM and the University of Hamburg and the Ship Research Establishment in Hamburg, West Germany. A summary is given of the benefits from the NASA project to UWM, the College of Engineering and Applied Science, and the participants on the project.

Structural analysis of high-rpm composite propfan blades for a cruise missile wind tunnel model

NASA Technical Reports Server (NTRS)

Carek, David A.

1993-01-01

Analyses were performed on a high-speed composite blade set for the Department of Defense Propfan Missile Interactions Project. The final design iteration, which resulted in the CM2D-2 blade design, is described in this report. Mode shapes, integral order excitation, and stress margins were examined. In addition, geometric corrections were performed to compensate for blade deflection under operating conditions with respect to the aerodynamic design shape.

Rick Damiani | NREL

Science.gov Websites

design and analysis of blades and support structures. Rick also supports various technical projects 15 years. He focuses on aeroelastic modeling of turbines and structural design and analysis of blades

Enhancement to Non-Contacting Stress Measurement of Blade Vibration Frequency

NASA Technical Reports Server (NTRS)

Platt, Michael; Jagodnik, John

2011-01-01

A system for turbo machinery blade vibration has been developed that combines time-of-arrival sensors for blade vibration amplitude measurement and radar sensors for vibration frequency and mode identification. The enabling technology for this continuous blade monitoring system is the radar sensor, which provides a continuous time series of blade displacement over a portion of a revolution. This allows the data reduction algorithms to directly calculate the blade vibration frequency and to correctly identify the active modes of vibration. The work in this project represents a significant enhancement in the mode identification and stress calculation accuracy in non-contacting stress measurement system (NSMS) technology when compared to time-of-arrival measurements alone.

Flow field analysis of high-speed helium turboexpander for cryogenic refrigeration and liquefaction cycles

NASA Astrophysics Data System (ADS)

Sam, Ashish Alex; Ghosh, Parthasarathi

2017-03-01

Turboexpander constitutes one of the vital components of Claude cycle based helium refrigerators and liquefiers that are gaining increasing technological importance. These turboexpanders which are of radial inflow in configuration are generally high-speed micro turbines, due to the low molecular weight and density of helium. Any improvement in efficiency of these machines requires a detailed understanding of the flow field. Computational Fluid Dynamics analysis (CFD) has emerged as a necessary tool for the determination of the flow fields in cryogenic turboexpanders, which is often not possible through experiments. In the present work three-dimensional transient flow analysis of a cryogenic turboexpander for helium refrigeration and liquefaction cycles were performed using Ansys CFX®, to understand the flow field of a high-speed helium turboexpander, which in turn will help in taking appropriate decisions regarding modifications of established design methodology for improved efficiency of these machines. The turboexpander is designed based on Balje's nsds diagram and the inverse design blade profile generation formalism prescribed by Hasselgruber and Balje. The analyses include the study of several losses, their origins, the increase in entropy due to these losses, quantification of losses and the effects of various geometrical parameters on these losses. Through the flow field analysis it was observed that in the nozzle, flow separation at the nozzle blade suction side and trailing edge vortices resulted in loss generation, which calls for better nozzle blade profile. The turbine wheel flow field analysis revealed that the significant geometrical parameters of the turbine wheel blade like blade inlet angle, blade profile, tip clearance height and trailing edge thickness need to be optimised for improved performance of the turboexpander. The detailed flow field analysis in this paper can be used to improve the mean line design methodology for turboexpanders used in helium refrigeration and liquefaction cycles.

81. photographer unknown 11 June 1937 WORKMEN ON TURBINE BLADES ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

81. photographer unknown 11 June 1937 WORKMEN ON TURBINE BLADES BEFORE LOWERING INTO DRAFT TUBE LINER. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

High Temperature Investigations into an Active Turbine Blade Tip Clearance Control Concept

NASA Technical Reports Server (NTRS)

Taylor, Shawn; Steinetz, Bruce M.; Oswald, Jay J.

2007-01-01

System studies have shown the benefits of reducing blade tip clearances in modern turbine engines. Minimizing blade tip clearances throughout the engine will contribute materially to meeting NASA s Ultra-Efficient Engine Technology (UEET) turbine engine project goals. NASA GRC is examining two candidate approaches including rub-avoidance and regeneration which are explained in subsequent slides.

High Temperature Investigations into an Active Turbine Blade Tip Clearance Control Concept

NASA Technical Reports Server (NTRS)

Taylor, Shawn C.; Steinetz, Bruce; Oswald, Jay J.

2008-01-01

System studies have shown the benefits of reducing blade tip clearances in modern turbine engines. Minimizing blade tip clearances throughout the engine will contribute materially to meeting NASA s Ultra-Efficient Engine Technology (UEET) turbine engine project goals. NASA GRC is examining two candidate approaches including rub-avoidance and regeneration which are explained in subsequent slides.

Oxide-dispersion-strengthened turbine blades, volume 1

NASA Technical Reports Server (NTRS)

Millan, P. P., Jr.; Mays, J. C.

1986-01-01

The objective of Project 4 was to develop a high-temperature, uncooled gas turbine blade using MA6000 alloy. The program objectives were achieved. Production scale up of the MA6000 alloy was achieved with a fair degree of tolerance to nonoptimum processing. The blade manufacturing process was also optimized. The mechanical, environmental, and physical property evaluations of MA6000 were conducted. The ultimate tensile strength, to about 704 C (130 F), is higher than DS MAR-M 247 but with a corresponding lower tensile elongation. Also, above 982 C (180 F) MA6000 tensile strength does not decrease as rapidly as MAR-M 247 because the ODS mechanism still remains active. Based on oxidation resistance and diffusional stability considerations, NiCrAlY coatings are recommended. CoCrAly coating should be applied on top of a thin NiCrAlY coating. Vibration tests, whirlpit tests, and a high-rotor-rig test were conducted to ensure successful completion of the engine test of the MA6000 TFE731 high pressure turbine blades. The results of these tests were acceptable. In production quantities, the cost of the Project 4 MA6000 blade is estimated to be about twice that of a cast DS MAR-M 247 blade.

Oxide-dispersion-strengthened turbine blades. Volume 2

NASA Technical Reports Server (NTRS)

Millan, P. P., Jr.; Mays, J. C.; Humbert, D. R.

1987-01-01

The overall objective of Project 4 was to develop and test a high-temperature, uncooled gas turbine blade using MA6000 alloy. Production scale up of the MA6000 alloy was achieved with a fair degree of tolerance to non-optimum processing. The blade manufacturing process was also optimized. The mechanical, environmental, and physical property evaluations of MA6000 were conducted. The ultimate tensile strength, to about 704 C (1300 F), is higher than DS MAR-M 247 but with a corresponding lower tensile elongation. Also, above 982 C (1800 F) MA6000 tensile strength does not decrease as rapidly as MAR-M 247 because the ODS mechanism still remains active. Based on oxidation resistance and diffusional stability considerations, NiCrAlY coatings are recommended. CoCrAlY coating should be applied on top of a thin NiCrAlY coating if hot corrosion is expected. Vibration, whirlpit, and high-rotor-rig tests were conducted to ensure successful completion of the engine test of the MA6000 TFE731 high pressure turbine blades. Test results were acceptable. In production quantities, the cost of the Project 4 MA6000 blade is estimated to be twice that of a cast DS MAR-M 247 blade.

Optimising ICT Effectiveness in Instruction and Learning: Multilevel Transformation Theory and a Pilot Project in Secondary Education

ERIC Educational Resources Information Center

Mooij, Ton

2004-01-01

Specific combinations of educational and ICT conditions including computer use may optimise learning processes, particularly for learners at risk. This position paper asks which curricular, instructional, and ICT characteristics can be expected to optimise learning processes and outcomes, and how to best achieve this optimization. A theoretical…

Experimental Permeability Measurements on a Strut-Supported Transpiration-Cooled Turbine Blade with Stainless-Steel Shell made by the Federal-Mogul Corporation under Bureau of Aeronautics Contract N0as 51613-C

NASA Technical Reports Server (NTRS)

Richards, Hadley T.

1954-01-01

A turbine blade with a porous stainless-steel shell sintered to a supporting steel strut has been fabricated for tests at the NACA by Federal-Mogul Corporation under contract from the Bureau of Aeronautics, Department of the Navy. The apparent permeability of this blade, on the average, more nearly approaches the values specified by the NAGA than did two strut-supported bronze blades in a previous investigation. Random variations of permeability in the present blade are substantialy greater than those of the bronze blades, but projected improvements in certain phases of the fabrication process are expected to reduce these variations.

Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 2: Project planning data

NASA Technical Reports Server (NTRS)

1980-01-01

Project planning data for a rotor and control system procurement and testing program for modifications to the XV-15 tilt-rotor research demonstrator aircraft is presented. The design, fabrication, and installation of advanced composite blades compatible with the existing hub, an advanced composite hub, and a nonmechanical control system are required.

Fiberglass composite blades for the 2 MW Mod-1 wind turbine generator

NASA Technical Reports Server (NTRS)

Batesole, W. R.

1982-01-01

In mid-1979, NASA contracted with Kaman Aerospace Corporation for the design, manufacture, and ground testing of two 100 foot composite rotor blades intended for operation on the Mod-1 wind turbine. The Mod-1 blades have been completed and are currently stored at the Kaman facility. The design, tooling, fabrication, and testing phases which have been carried out to date, as well as testing still planned are described. Discussed are differences from the 150 foot blade which were introduced for cost and manufacturing improvement purposes. Also included is a description of the lightning protection system installed in the blades, and its development program. Actual costs and manhours expended for Blade No. 2 are provided as a base, along with a projection of costs for the blade in production. Finally, cost drivers are identified relative to future designs.

Manufacturing Methods and Technology Project Summary Reports

DTIC Science & Technology

1982-12-01

aluminide was used to eliminate adhesive failures. A doctor blade and expandable ring segment were selected as the tooling to apply the 0.010 inch...contractual effort is to develop manu- facturing technology for the production of integrally bladed impellers using titanium pre-alloyed powder and...Projectiles in Modernized Plants 1-16 METALS Abstracts ME-1 Projects 176 7046, 17T 7046 and 177 7046 - Precision Cast Titanium Compressor Casing ME

Technical Assessment of the National Full Scale Aerodynamic Complex Fan Blades Repair

NASA Technical Reports Server (NTRS)

Young, Clarence P., Jr.; Dixon, Peter G.; St.Clair, Terry L.; Johns, William E.

1998-01-01

This report describes the principal activities of a technical review team formed to address National Full Scale Aerodynamic Complex (NFAC) blade repair problems. In particular, the problem of lack of good adhesive bonding of the composite overwrap to the Hyduliginum wood blade material was studied extensively. Description of action plans and technical elements of the plans are provided. Results of experiments designed to optimize the bonding process and bonding strengths obtained on a full scale blade using a two-step cure process with adhesive primers are presented. Consensus recommendations developed by the review team in conjunction with the NASA Ames Fan Blade Repair Project Team are provided along with lessons learned on this program. Implementation of recommendations resulted in achieving good adhesive bonds between the composite materials and wooden blades, thereby providing assurance that the repaired fan blades will meet or exceed operational life requirements.

Combined Amplitude and Frequency Measurements for Non-Contacting Turbomachinery Blade Vibration

NASA Technical Reports Server (NTRS)

Jagodnik, John J. (Inventor); Platt, Michael J. (Inventor)

2013-01-01

A method and apparatus for measuring the vibration of rotating blades, such as turbines, compressors, fans, or pumps, including sensing the return signal from projected energy and/or field changes from a plurality of sensors mounted on the machine housing. One or more of the sensors has a narrow field of measurement and the data is processed to provide the referenced time of arrival of each blade, and therefore the blade tip deflection due to vibration. One or more of the sensors has a wide field of measurement, providing a time history of the approaching and receding blades, and the data is processed to provide frequency content and relative magnitudes of the active mode(s) of blade vibration. By combining the overall tip deflection magnitude with the relative magnitudes of the active modes, the total vibratory stress state of the blade can be determined.

Sweep-twist adaptive rotor blade : final project report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashwill, Thomas D.

2010-02-01

Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercialmore » development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.« less

Fort Leonard Wood German POW Stonework: Maintenance and Repair

DTIC Science & Technology

2017-07-01

powered chisels, scaler (power chipper), and thin diamond- bladed grinders should be approved by architect or project manager. All work should be...Figure 5. Deteriorated mortar and plant growth on the patio of Garlington House. Photo NCPTT 8 • Raising mower blades to avoid low-ly- ing features...protective perimeter around features, attaching protective bumpers to the lawn mower, raising mower blades to avoid low-lying features, and using smaller

Oxide-dispersion-strengthened turbine blades, volume 1. [MA6000 alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millan, P.P. Jr.; Mays, J.C.

1986-10-01

The objective of Project 4 was to develop a high-temperature, uncooled gas turbine blade using MA6000 alloy. The program objectives were achieved. Production scale up of the MA6000 alloy was achieved with a fair degree of tolerance to nonoptimum processing. The blade manufacturing process was also optimized. The mechanical, environmental, and physical property evaluations of MA6000 were conducted. The ultimate tensile strength, to about 704 C (130 F), is higher than DS MAR-M 247 but with a corresponding lower tensile elongation. Also, above 982 C (180 F) MA6000 tensile strength does not decrease as rapidly as MAR-M 247 because themore » ODS mechanism still remains active. Based on oxidation resistance and diffusional stability considerations, NiCrAlY coatings are recommended. CoCrAly coating should be applied on top of a thin NiCrAlY coating. Vibration tests, whirlpit tests, and a high-rotor-rig test were conducted to ensure successful completion of the engine test of the MA6000 TFE731 high pressure turbine blades. The results of these tests were acceptable. In production quantities, the cost of the Project 4 MA6000 blade is estimated to be about twice that of a cast DS MAR-M 247 blade.« less

Fabrication of Organic Radar Absorbing Materials: A Report on the TIF Project

DTIC Science & Technology

2005-05-01

thickness, permittivity and permeability. The ability to measure the permittivity and permeability is an essential requirement for designing an optimised...absorber. And good optimisations codes are required in order to achieve the best possible absorber designs . In this report, the results from a...through measurement of their conductivity and permittivity at microwave frequencies. Methods were then developed for optimising the design of

Evaluation of Aeroelastically Tailored Small Wind Turbine Blades Final Project Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffin, Dayton A.

2005-09-29

Evaluation of Aeroelastically Tailored Small Wind Turbine Blades Final Report Global Energy Concepts, LLC (GEC) has performed a conceptual design study concerning aeroelastic tailoring of small wind turbine blades. The primary objectives were to evaluate ways that blade/rotor geometry could be used to enable cost-of-energy reductions by enhancing energy capture while constraining or mitigating blade costs, system loads, and related component costs. This work builds on insights developed in ongoing adaptive-blade programs but with a focus on application to small turbine systems with isotropic blade material properties and with combined blade sweep and pre-bending/pre-curving to achieve the desired twist coupling.more » Specific goals of this project are to: (A) Evaluate and quantify the extent to which rotor geometry can be used to realize load-mitigating small wind turbine rotors. Primary aspects of the load mitigation are: (1) Improved overspeed safety affected by blades twisting toward stall in response to speed increases. (2) Reduced fatigue loading affected by blade twisting toward feather in response to turbulent gusts. (B) Illustrate trade-offs and design sensitivities for this concept. (C) Provide the technical basis for small wind turbine manufacturers to evaluate this concept and commercialize if the technology appears favorable. The SolidWorks code was used to rapidly develop solid models of blade with varying shapes and material properties. Finite element analyses (FEA) were performed using the COSMOS code modeling with tip-loads and centripetal accelerations. This tool set was used to investigate the potential for aeroelastic tailoring with combined planform sweep and pre-curve. An extensive matrix of design variables was investigated, including aerodynamic design, magnitude and shape of planform sweep, magnitude and shape of blade pre-curve, material stiffness, and rotor diameter. The FEA simulations resulted in substantial insights into the structural response of these blades. The trends were used to identify geometries and rotor configurations that showed the greatest promise for achieving beneficial aeroelastic response. The ADAMS code was used to perform complete aeroelastic simulations of selected rotor configurations; however, the results of these simulations were not satisfactory. This report documents the challenges encountered with the ADAMS simulations and presents recommendations for further development of this concept for aeroelastically tailored small wind turbine blades.« less

Tangential RIF turbine with particle removing means

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linhardt, H.D.

1980-12-02

A radial inflow turbine is disclosed utilizing a star wheel type of blade and wherein the inlet nozzles are located along the sides or lateral of the blade tips rather than located radially beyond the blade tips. The side approach enables the turbine to include an annular chamber outside of the moving blades and where small particles are centrifuged during operation and collected. The incoming hot gases, that propel the blades, pass through approximately a 90/sup 0/ turn and continue radially inwardly. The large particles hit the turbine blades and are projected outwardly into the annular chamber for collection andmore » subsequent removal while the smaller particles may be centrifuged in the stream of gas and immediately thrown outwardly. The turbine is capable of removing particles to as small as 2-3 microns (..mu..m).« less

Advanced blade tip seal system, volume 2

NASA Technical Reports Server (NTRS)

Zelahy, J. W.; Fairbanks, N. P.

1982-01-01

The results of the endurance and performance engine tests conducted on monocrystal/abrasive-tipped CF6-50 Stage 1 HPT blades fabricated in Task VII of MATE Project 3 are presented. Two engine tests are conducted. The endurance engine test is conducted for 1000 C cycles. The performance engine test is conducted on a variable cycle core engine. Posttest evaluation and analyses of the blades and shrouds included visual, dimensional, and destructive evaluations.

The Development and Hover Test Application of a Projection Moire Interferometry Blade Displacement Measurement System

NASA Technical Reports Server (NTRS)

Sekula, Martin K.

2012-01-01

Projection moir interferometry (PMI) was employed to measure blade deflections during a hover test of a generic model-scale rotor in the NASA Langley 14x22 subsonic wind tunnel s hover facility. PMI was one of several optical measurement techniques tasked to acquire deflection and flow visualization data for a rotor at several distinct heights above a ground plane. Two of the main objectives of this test were to demonstrate that multiple optical measurement techniques can be used simultaneously to acquire data and to identify and address deficiencies in the techniques. Several PMI-specific technical challenges needed to be addressed during the test and in post-processing of the data. These challenges included developing an efficient and accurate calibration method for an extremely large (65 inch) height range; automating the analysis of the large amount of data acquired during the test; and developing a method to determinate the absolute displacement of rotor blades without a required anchor point measurement. The results indicate that the use of a single-camera/single-projector approach for the large height range reduced the accuracy of the PMI system compared to PMI systems designed for smaller height ranges. The lack of the anchor point measurement (due to a technical issue with one of the other measurement techniques) limited the ability of the PMI system to correctly measure blade displacements to only one of the three rotor heights tested. The new calibration technique reduced the data required by 80 percent while new post-processing algorithms successfully automated the process of locating rotor blades in images, determining the blade quarter chord location, and calculating the blade root and blade tip heights above the ground plane.

Design of an AdvancedTCA board management controller (IPMC)

NASA Astrophysics Data System (ADS)

Mendez, J.; Bobillier, V.; Haas, S.; Joos, M.; Mico, S.; Vasey, F.

2017-03-01

The AdvancedTCA (ATCA) standard has been selected as the hardware platform for the upgrade of the back-end electronics of the CMS and ATLAS experiments of the Large Hadron Collider (LHC) . In this context, the electronic systems for experiments group at CERN is running a project to evaluate, specify, design and support xTCA equipment. As part of this project, an Intelligent Platform Management Controller (IPMC) for ATCA blades, based on a commercial solution, has been designed to be used on existing and future ATCA blades. This paper reports on the status of this project presenting the hardware and software developments.

Synoptic versus regional causes of icing on wind turbines at an exposed wind farm site in Germany

NASA Astrophysics Data System (ADS)

Weissinger, Maximilian; Strauss, Lukas; Serafin, Stefano; Dorninger, Manfred; Burchhart, Thomas; Fink, Martin

2017-04-01

Ice accretion on wind turbine blades can lead to significant power production loss or even permanent structural damage on the turbine. With the ongoing construction of wind farms at sites with increased icing potential in cold climates, accurate icing predictions are needed to optimise power plant operation. To this end, the frequency of occurrence and the causes of meteorological icing need to be better understood. The project ICE CONTROL, an Austrian research initiative, aims to improve icing forecasts through measurements, probabilistic forecasting, and verification of icing on wind turbine blades. The project focuses on a wind farm site near Ellern, Germany, located on the Hunsrück, a hilly terrain rising above the surrounding plain by 200-300 metres. Production data from the last three winters show that icing events tend to occur more often at the wind turbines on top of the highest hills. The present study aims to investigate historical cases of wind turbine icing and their meteorological causes at the Ellern wind farm. The data available consists of a three-year period (2013-2016) of operational data from the Ellern wind farm as well as meteorological measurements at nearby stations operated by the German Weather Service (DWD). In addition, radiosondes and weather charts are taken into account. The main objective of this work is, first, to link the local and regional weather conditions to larger-scale weather patterns and prevailing air masses, and second, to determine the types of icing (in-cloud vs. freezing precipation). Results show that in most icing cases the cloud base height was below the hub height while the temperature was just below the freezing point. Precipitation was absent in most cases. This suggests that most of the observed icing events were due to in-cloud icing. Icing conditions occurred often (but not exclusively) under specific synoptic-scale weather conditions, such as north-westerly flow advecting maritime polar air masses to Central Europe. In other cases, icing events were favoured by the development of low-level thermal inversions during weak south-easterly flow conditions.

Helicopter rotor wake geometry and its influence in forward flight. Volume 2: Wake geometry charts

NASA Technical Reports Server (NTRS)

Egolf, T. A.; Landgrebe, A. J.

1983-01-01

Isometric and projection view plots, inflow ratio nomographs, undistorted axial displacement nomographs, undistorted longitudinal and lateral coordinates, generalized axial distortion nomographs, blade/vortex passage charts, blade/vortex intersection angle nomographs, and fore and aft wake boundary charts are discussed. Example condition, in flow ratio, undistorted axial location, longitudinal and lateral coordinates, axial coordinates distortions, blade/tip vortex intersections, angle of intersection, and fore and aft wake boundaries are also discussed.

Computer aided design and manufacturing of composite propfan blades for a cruise missile wind tunnel model

NASA Technical Reports Server (NTRS)

Thorp, Scott A.; Downey, Kevin M.

1992-01-01

One of the propulsion concepts being investigated for future cruise missiles is advanced unducted propfans. To support the evaluation of this technology applied to the cruise missile, a joint DOD and NASA test project was conducted to design and then test the characteristics of the propfans on a 0.55-scale, cruise missile model in a NASA wind tunnel. The configuration selected for study is a counterrotating rearward swept propfan. The forward blade row, having six blades, rotates in a counterclockwise direction, and the aft blade row, having six blades, rotates in a clockwise direction, as viewed from aft of the test model. Figures show the overall cruise missile and propfan blade configurations. The objective of this test was to evaluate propfan performance and suitability as a viable propulsion option for next generation of cruise missiles. This paper details the concurrent computer aided design, engineering, and manufacturing of the carbon fiber/epoxy propfan blades as the NASA Lewis Research Center.

Design and initial testing of a one-bladed 30-meter-diameter rotor on the NASA/DOE mod-O wind turbine

NASA Technical Reports Server (NTRS)

Corrigan, R. D.; Ensworth, C. B. F.

1986-01-01

The concept of a one-bladed horizontal-axis wind turbine has been of interest to wind turbine designers for many years. Many designs and economic analyses of one-bladed wind turbines have been undertaken by both United States and European wind energy groups. The analyses indicate significant economic advantages but at the same time, significant dynamic response concerns. In an effort to develop a broad data base on wind turbine design and operations, the NASA Wind Energy Project Office has tested a one-bladed rotor at the NASA/DOE Mod-O Wind Turbine Facility. This is the only known test on an intermediate-sized one-bladed rotor in the United States. The 15.2-meter-radius rotor consists of a tip-controlled blade and a counterweight assembly. A rigorous test series was conducted in the Fall of 1985 to collect data on rotor performance, drive train/generator dynamics, structural dynamics, and structural loads. This report includes background information on one-bladed rotor concepts, and Mod-O one-bladed rotor test configuration, supporting design analysis, the Mod-O one-blade rotor test plan, and preliminary test results.

Large Wind Energy Converter: Growian 3 MW

NASA Technical Reports Server (NTRS)

Feustel, J. E.; Helm, S.; Koerber, F.

1980-01-01

The final report on the projected application of larger-scale wind turbine on the northern German coast is summarized. The designs of the tower, machinery housing, rotor, and rotor blades are described accompanied various construction materials are examined. Rotor blade adjustment devices auxiliary and accessory equipment are examined.

The development and manufacture of wood composite wind turbine rotors

NASA Technical Reports Server (NTRS)

Zuteck, M. D.

1982-01-01

The physical properties, operational experience, and construction methods of the wood/epoxy composite MOD 0A wind turbine blades are considered. Blades of this type have accumulated over 10,000 hours of successful operation at the Kahuku, Hawaii and Block Island, Rhode Island test sites. That body of experience is summarized and related to the structural concepts and design drivers which motivated the original design and choice of interior layout. Actual manufacturing experience and associated low first unit costs for these blades, as well as projections for high production rates, are presented. Application of these construction techniques to a wide range of other blade sizes is also considered.

Numerical investigation of the self-starting of a vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Tsai, Hsieh-Chen; Colonius, Tim

2014-11-01

The immersed boundary method is used to simulate the incompressible flow around two-dimensional airfoils at sub-scale Reynolds number in order to investigate the self-starting capability of a vertical-axis wind turbine (VAWT). By investigating a single blade fixed at various angle of attacks, the leading edge vortex (LEV) is shown to play an important role in the starting mechanism for both flat-plate and NACA 0018 blades. Depending on the angle of attack of the blade, as the LEV grows, the corresponding low pressure region results in a thrust in the tangential direction, which produces a positive torque to VAWT. Due to the characteristics of the blades, a NACA 0018 blade produces a larger thrust over a wider range of angle of attacks than a flat-plate blade. Therefore, a VAWT with NACA 0018 blades can self-start more easily than one with flat-plate blades. Moreover, by investigating the starting torque of three-bladed VAWTs fixed at various orientations, the optimal orientation that produces the largest torque to start both VAWTs is with a blade parallel to the flow and facing downstream. The simulations are also compared to results from companion water-tunnel experiments at Caltech. This project is supported by Caltech FLOWE center/Gordon and Betty Moore Foundation.

Implementation of a Biaxial Resonant Fatigue Test Method on a Large Wind Turbine Blade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snowberg, D.; Dana, S.; Hughes, S.

2014-09-01

A biaxial resonant test method was utilized to simultaneously fatigue test a wind turbine blade in the flap and edge (lead-lag) direction. Biaxial resonant blade fatigue testing is an accelerated life test method utilizing oscillating masses on the blade; each mass is independently oscillated at the respective flap and edge blade resonant frequency. The flap and edge resonant frequency were not controlled, nor were they constant for this demonstrated test method. This biaxial resonant test method presented surmountable challenges in test setup simulation, control and data processing. Biaxial resonant testing has the potential to complete test projects faster than single-axismore » testing. The load modulation during a biaxial resonant test may necessitate periodic load application above targets or higher applied test cycles.« less

Optimisation of the Management of Higher Activity Waste in the UK - 13537

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, Ciara; Buckley, Matthew

2013-07-01

The Upstream Optioneering project was created in the Nuclear Decommissioning Authority (UK) to support the development and implementation of significant opportunities to optimise activities across all the phases of the Higher Activity Waste management life cycle (i.e. retrieval, characterisation, conditioning, packaging, storage, transport and disposal). The objective of the Upstream Optioneering project is to work in conjunction with other functions within NDA and the waste producers to identify and deliver solutions to optimise the management of higher activity waste. Historically, optimisation may have occurred on aspects of the waste life cycle (considered here to include retrieval, conditioning, treatment, packaging, interimmore » storage, transport to final end state, which may be geological disposal). By considering the waste life cycle as a whole, critical analysis of assumed constraints may lead to cost savings for the UK Tax Payer. For example, it may be possible to challenge the requirements for packaging wastes for disposal to deliver an optimised waste life cycle. It is likely that the challenges faced in the UK are shared in other countries. It is therefore likely that the opportunities identified may also apply elsewhere, with the potential for sharing information to enable value to be shared. (authors)« less

Blade system design studies volume II : preliminary blade designs and recommended test matrix.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffin, Dayton A.

2004-06-01

As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT) program, Global Energy Concepts, LLC is performing a Blade System Design Study (BSDS) concerning innovations in materials, processes and structural configurations for application to wind turbine blades in the multi-megawatt range. The BSDS Volume I project report addresses issues and constraints identified to scaling conventional blade designs to the megawatt size range, and evaluated candidate materials, manufacturing and design innovations for overcoming and improving large blade economics. The current report (Volume II), presents additional discussion of materials and manufacturing issues for large blades, including amore » summary of current trends in commercial blade manufacturing. Specifications are then developed to guide the preliminary design of MW-scale blades. Using preliminary design calculations for a 3.0 MW blade, parametric analyses are performed to quantify the potential benefits in stiffness and decreased gravity loading by replacement of a baseline fiberglass spar with carbon-fiberglass hybrid material. Complete preliminary designs are then presented for 3.0 MW and 5.0 MW blades that incorporate fiberglass-to-carbon transitions at mid-span. Based on analysis of these designs, technical issues are identified and discussed. Finally, recommendations are made for composites testing under Part I1 of the BSDS, and the initial planned test matrix for that program is presented.« less

Test Rig for Active Turbine Blade Tip Clearance Control Concepts: An Update

NASA Technical Reports Server (NTRS)

Taylor, Shawn; Steinetz, Bruce; Oswald, Jay; DeCastro, Jonathan; Melcher, Kevin

2006-01-01

The objective is to develop and demonstrate a fast-acting active clearance control system to improve turbine engine performance, reduce emissions, and increase service life. System studies have shown the benefits of reducing blade tip clearances in modern turbine engines. Minimizing blade tip clearances throughout the engine will contribute materially to meeting NASA's Ultra-Efficient Engine Technology (UEET) turbine engine project goals. NASA GRC is examining two candidate approaches including rub-avoidance and regeneration which are explained in subsequent slides.

Sub-scale Inverse Wind Turbine Blade Design Using Bound Circulation

NASA Astrophysics Data System (ADS)

Kelley, Christopher; Berg, Jonathan

2014-11-01

A goal of the National Rotor Testbed project at Sandia is to design a sub-scale wind turbine blade that has similitude to a modern, commercial size blade. However, a smaller diameter wind turbine operating at the same tip-speed-ratio exhibits a different range of operating Reynolds numbers across the blade span, thus changing the local lift and drag coefficients. Differences to load distribution also affect the wake dynamics and stability. An inverse wind turbine blade design tool has been implemented which uses a target, dimensionless circulation distribution from a full-scale blade to find the chord and twist along a sub-scale blade. In addition, airfoil polar data are interpolated from a few specified span stations leading to a smooth, manufacturable blade. The iterative process perturbs chord and twist, after running a blade element momentum theory code, to reduce the residual sum of the squares between the modeled sub-scale circulation and the target full-scale circulation. It is shown that the converged sub-scale design also leads to performance similarity in thrust and power coefficients. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy under Contract DE-AC04-94AL85000.

Experimental investigation of the flow field and power consumption characteristics of regular and fractal blade impellers in a dynamic mixer

NASA Astrophysics Data System (ADS)

Steiros, K.; Bruce, P. J. K.; Buxton, O. R. H.; Vassilicos, J. C.

2015-11-01

Experiments have been performed in an octagonal un-baffled water tank, stirred by three radial turbines with different geometry impellers: (1) regular rectangular blades; (2) single-iteration fractal blades; (3) two-iteration fractal blades. Shaft torque was monitored and the power number calculated for each case. Both impellers with fractal geometry blades exhibited a decrease of turbine power number compared to the regular one (15% decrease for single-iteration and 19% for two iterations). Phase locked PIV in the discharge region of the blades revealed that the vortices emanating from the regular blades are more coherent, have higher kinetic energy, and advect faster towards the tank's walls where they are dissipated, compared to their fractal counterparts. This suggests a strong link between vortex production and behaviour and the energy input for the different impellers. Planar PIV measurements in the bulk of the tank showed an increase of turbulence intensity of over 20% for the fractal geometry blades, suggesting higher mixing efficiency. Experiments with pressure measurements on the different geometry blade surfaces are ongoing to investigate the distribution of forces, and calculate hydrodynamic centres of pressure. The authors would like to acknowledge the financial support given by European Union FP7 Marie Curie MULTISOLVE project (Grant Agreement No. 317269).

Fiber reinforced superalloys for rocket engines

NASA Technical Reports Server (NTRS)

Petrasek, Donald W.; Stephens, Joseph R.

1989-01-01

High pressure turbopumps for advanced reusable liquid propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several fold increase in life and over a 200 C increase in temperature capability over the current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

Fiber reinforced superalloys for rocket engines

NASA Technical Reports Server (NTRS)

Petrasek, Donald W.; Stephens, Joseph R.

1988-01-01

High-pressure turbopumps for advanced reusable liquid-propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several-fold increase in life and over a 200C increase in temperature capability over current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

Evaluating Effects of Stressors from Marine and Hydrokinetic Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Copping, Andrea E.; Blake, Kara M.; Hanna, Luke A.

2012-09-30

Potential environmental effects of marine and hydrokinetic (MHK) energy development are not well understood, yet regulatory agencies are required to make decisions in spite of substantial uncertainty about environmental impacts and their long-term consequences. An understanding of risks associated with interactions between MHK installations and aquatic receptors, including animals, habitats, and ecosystems, can help define key uncertainties and focus regulatory actions and scientific studies on interactions of most concern. During FY 2012, Pacific Northwest National Laboratory (PNNL) continued to follow project developments on the two marine and hydrokinetic projects reviewed for Environmental Risk Evaluation System (ERES) screening analysis in FYmore » 2011: a tidal project in the Gulf of Maine using Ocean Renewable Power Company TidGenTM turbines and a wave project planned for the coast of Oregon using Aquamarine Oyster surge devices. The ERES project in FY 2012 also examined two stressor–receptor interactions previously identified through the screening process as being of high importance: 1) the toxicity effects of antifouling coatings on MHK devices on aquatic resources and 2) the risk of a physical strike encounter between an adult killer whale and an OpenHydro turbine blade. The screening-level assessment of antifouling paints and coatings was conducted for two case studies: the Snohomish County Public Utility District No. 1 (SnoPUD) tidal turbine energy project in Admiralty Inlet, Puget Sound, Washington, and the Ocean Power Technologies (OPT) wave buoy project in Reedsport, Oregon. Results suggest minimal risk to aquatic biota from antifouling coatings used on MHK devices deployed in large estuaries or open ocean environments. For the strike assessment of a Southern Resident Killer Whale (SRKW) encountering an OpenHydro tidal turbine blade, PNNL teamed with colleagues from Sandia National Laboratories (SNL) to carry out an analysis of the mechanics and biological consequences of different blade strike scenarios. Results of these analyses found the following: 1) a SRKW is not likely to experience significant tissue injury from impact by an OpenHydro turbine blade; and 2) if whale skin behaves similarly to the materials considered as surrogates for the upper dermal layers of whale skin, it would not be torn by an OpenHydro blade strike. The PNNL/SNL analyses could not provide insight into the potential for more subtle changes to SRKWs from an encounter with a turbine, such as changes in behavior, or inform turbine interactions for other whales or other turbines. These analyses were limited by the available time frame in which results were needed and focused on the mechanical response of whale tissues and bone to blade strike. PNNL proposes that analyses of additional turbine designs and interactions with other marine mammals that differ in size, body conformation, and mass be performed.« less

Aerodynamic design of the National Rotor Testbed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelley, Christopher Lee

2015-10-01

A new wind turbine blade has been designed for the National Rotor Testbed (NRT) project and for future experiments at the Scaled Wind Farm Technology (SWiFT) facility with a specific focus on scaled wakes. This report shows the aerodynamic design of new blades that can produce a wake that has similitude to utility scale blades despite the difference in size and location in the atmospheric boundary layer. Dimensionless quantities circulation, induction, thrust coefficient, and tip-speed-ratio were kept equal between rotor scales in region 2 of operation. The new NRT design matched the aerodynamic quantities of the most common wind turbinemore » in the United States, the GE 1.5sle turbine with 37c model blades. The NRT blade design is presented along with its performance subject to the winds at SWiFT. The design requirements determined by the SWiFT experimental test campaign are shown to be met.« less

Virtual Reality Used to Serve the Glenn Engineering Community

NASA Technical Reports Server (NTRS)

Carney, Dorothy V.

2001-01-01

There are a variety of innovative new visualization tools available to scientists and engineers for the display and analysis of their models. At the NASA Glenn Research Center, we have an ImmersaDesk, a large, single-panel, semi-immersive display device. This versatile unit can interactively display three-dimensional images in visual stereo. Our challenge is to make this virtual reality platform accessible and useful to researchers. An example of a successful application of this computer technology is the display of blade out simulations. NASA Glenn structural dynamicists, Dr. Kelly Carney and Dr. Charles Lawrence, funded by the Ultra Safe Propulsion Project under Base R&T, are researching blade outs, when turbine engines lose a fan blade during operation. Key objectives of this research include minimizing danger to the aircraft via effective blade containment, predicting destructive loads due to the imbalance following a blade loss, and identifying safe, cost-effective designs and materials for future engines.

Comparing approaches for using climate projections in assessing water resources investments for systems with multiple stakeholder groups

NASA Astrophysics Data System (ADS)

Hurford, Anthony; Harou, Julien

2015-04-01

Climate change has challenged conventional methods of planning water resources infrastructure investment, relying on stationarity of time-series data. It is not clear how to best use projections of future climatic conditions. Many-objective simulation-optimisation and trade-off analysis using evolutionary algorithms has been proposed as an approach to addressing complex planning problems with multiple conflicting objectives. The search for promising assets and policies can be carried out across a range of climate projections, to identify the configurations of infrastructure investment shown by model simulation to be robust under diverse future conditions. Climate projections can be used in different ways within a simulation model to represent the range of possible future conditions and understand how optimal investments vary according to the different hydrological conditions. We compare two approaches, optimising over an ensemble of different 20-year flow and PET timeseries projections, and separately for individual future scenarios built synthetically from the original ensemble. Comparing trade-off curves and surfaces generated by the two approaches helps understand the limits and benefits of optimising under different sets of conditions. The comparison is made for the Tana Basin in Kenya, where climate change combined with multiple conflicting objectives of water management and infrastructure investment mean decision-making is particularly challenging.

Viscous and Aeroelastic Effects on Wind Turbine Blades. The VISCEL Project. Part II: Aeroelastic Stability Investigations

NASA Astrophysics Data System (ADS)

Chaviaropoulos, P. K.; Soerensen, N. N.; Hansen, M. O. L.; Nikolaou, I. G.; Aggelis, K. A.; Johansen, J.; Gaunaa, Mac; Hambraus, T.; Frhr. von Geyr, Heiko; Hirsch, Ch.; Shun, Kang; Voutsinas, S. G.; Tzabiras, G.; Perivolaris, Y.; Dyrmose, S. Z.

2003-10-01

The recent introduction of ever larger wind turbines poses new challenges with regard to understanding the mechanisms of unsteady flow-structure interaction. An important aspect of the problem is the aeroelastic stability of the wind turbine blades, especially in the case of combined flap/lead-lag vibrations in the stall regime. Given the limited experimental information available in this field, the use of CFD techniques and state-of-the-art viscous flow solvers provides an invaluable alternative towards the identification of the underlying physics and the development and validation of sound engineering-type aeroelastic models. Navier-Stokes-based aeroelastic stability analysis of individual blade sections subjected to combined pitch/flap or flap/lead-lag motion has been attempted by the present consortium in the framework of the concluded VISCEL JOR3-CT98-0208 Joule III project.

Accuracy of State-of-the-Art Actuator-Line Modeling for Wind Turbine Wakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jha, Pankaj; Churchfield, Matthew; Moriarty, Patrick

The current actuator line method (ALM) within an OpenFOAM computational fluid dynamics (CFD) solver was used to perform simulations of the NREL Phase VI rotor under rotating and parked conditions, two fixed-wing designs both with an elliptic spanwise loading, and the NREL 5-MW turbine. The objective of this work is to assess and improve the accuracy of the state-of-the-art ALM in predicting rotor blade loads, particularly by focusing on the method used to project the actuator forces onto the flow field as body forces. Results obtained for sectional normal and tangential force coefficients were compared to available experimental data andmore » to the in-house performance code XTurb-PSU. It was observed that the ALM results agree well with measured data and results obtained from XTurb-PSU except in the root and tip regions if a three-dimensional Gaussian of width, ε, constant along the blade span is used to project the actuator force onto the flow field. A new method is proposed where the Gaussian width, ε, varies along the blade span following an elliptic distribution. A general criterion is derived that applies to any planform shape. It is found that the new criterion for ε leads to improved prediction of blade tip loads for a variety of blade planforms and rotor conditions considered.« less

ATLAS software configuration and build tool optimisation

NASA Astrophysics Data System (ADS)

Rybkin, Grigory; Atlas Collaboration

2014-06-01

ATLAS software code base is over 6 million lines organised in about 2000 packages. It makes use of some 100 external software packages, is developed by more than 400 developers and used by more than 2500 physicists from over 200 universities and laboratories in 6 continents. To meet the challenge of configuration and building of this software, the Configuration Management Tool (CMT) is used. CMT expects each package to describe its build targets, build and environment setup parameters, dependencies on other packages in a text file called requirements, and each project (group of packages) to describe its policies and dependencies on other projects in a text project file. Based on the effective set of configuration parameters read from the requirements files of dependent packages and project files, CMT commands build the packages, generate the environment for their use, or query the packages. The main focus was on build time performance that was optimised within several approaches: reduction of the number of reads of requirements files that are now read once per package by a CMT build command that generates cached requirements files for subsequent CMT build commands; introduction of more fine-grained build parallelism at package task level, i.e., dependent applications and libraries are compiled in parallel; code optimisation of CMT commands used for build; introduction of package level build parallelism, i. e., parallelise the build of independent packages. By default, CMT launches NUMBER-OF-PROCESSORS build commands in parallel. The other focus was on CMT commands optimisation in general that made them approximately 2 times faster. CMT can generate a cached requirements file for the environment setup command, which is especially useful for deployment on distributed file systems like AFS or CERN VMFS. The use of parallelism, caching and code optimisation significantly-by several times-reduced software build time, environment setup time, increased the efficiency of multi-core computing resources utilisation, and considerably improved software developer and user experience.

Critical factors for optimising skill-grade-mix based on principles of Lean Management - a qualitative substudy

PubMed

Inauen, Alice; Rettke, Horst; Fridrich, Annemarie; Spirig, Rebecca; Bauer, Georg F

2017-01-01

Background: Due to scarce resources in health care, staff deployment has to meet the demands. To optimise skill-grade-mix, a Swiss University Hospital initiated a project based on principles of Lean Management. The project team accompanied each participating nursing department and scientifically evaluated the results of the project. Aim: The aim of this qualitative sub-study was to identify critical success factors of this project. Method: In four focus groups, participants discussed their experience of the project. Recruitment was performed from departments assessing the impact of the project retrospectively either positive or critical. In addition, the degree of direct involvement in the project served as a distinguishing criterion. Results: While the degree of direct involvement in the project was not decisive, conflicting opinions and experiences appeared in the groups with more positive or critical project evaluation. Transparency, context and attitude proved critical for the project’s success. Conclusions: Project managers should ensure transparency of the project’s progress and matching of the project structure with local conditions in order to support participants in their critical or positive attitude towards the project.

Low-cost single-crystal turbine blades, volume 2

NASA Technical Reports Server (NTRS)

Strangman, T. E.; Dennis, R. E.; Heath, B. R.

1984-01-01

The overall objectives of Project 3 were to develop the exothermic casting process to produce uncooled single-crystal (SC) HP turbine blades in MAR-M 247 and higher strength derivative alloys and to validate the materials process and components through extensive mechanical property testing, rig testing, and 200 hours of endurance engine testing. These Program objectives were achieved. The exothermic casting process was successfully developed into a low-cost nonproperietary method for producing single-crystal castings. Single-crystal MAR-M 247 and two derivatives DS alloys developed during this project, NASAIR 100 and SC Alloy 3, were fully characterized through mechanical property testing. SC MAR-M 247 shows no significant improvement in strength over directionally solidified (DS) MAR-M 247, but the derivative alloys, NASAIR 100 and Alloy 3, show significant tensile and fatigue improvements. Firtree testing, holography, and strain-gauge rig testing were used to determine the effects of the anisotropic characteristics of single-crystal materials. No undesirable characteristics were found. In general, the single-crystal material behaved similarly to DS MAR-M 247. Two complete engine sets of SC HP turbine blades were cast using the exothermic casting process and fully machined. These blades were successfully engine-tested.

Wind Turbine Load Mitigation based on Multivariable Robust Control and Blade Root Sensors

NASA Astrophysics Data System (ADS)

Díaz de Corcuera, A.; Pujana-Arrese, A.; Ezquerra, J. M.; Segurola, E.; Landaluze, J.

2014-12-01

This paper presents two H∞ multivariable robust controllers based on blade root sensors' information for individual pitch angle control. The wind turbine of 5 MW defined in the Upwind European project is the reference non-linear model used in this research work, which has been modelled in the GH Bladed 4.0 software package. The main objective of these controllers is load mitigation in different components of wind turbines during power production in the above rated control zone. The first proposed multi-input multi-output (MIMO) individual pitch H" controller mitigates the wind effect on the tower side-to-side acceleration and reduces the asymmetrical loads which appear in the rotor due to its misalignment. The second individual pitch H" multivariable controller mitigates the loads on the three blades reducing the wind effect on the bending flapwise and edgewise momentums in the blades. The designed H" controllers have been validated in GH Bladed and an exhaustive analysis has been carried out to calculate fatigue load reduction on wind turbine components, as well as to analyze load mitigation in some extreme cases.

Final Results from Mexnext-I: Analysis of detailed aerodynamic measurements on a 4.5 m diameter rotor placed in the large German Dutch Wind Tunnel DNW

NASA Astrophysics Data System (ADS)

Schepers, J. G.; Boorsma, K.; Munduate, X.

2014-12-01

The paper presents the final results from the first phase of IEA Task 29 'Mexnext'. Mexnext was a joint project in which 20 parties from 11 different countries cooperated. The main aim of Mexnext was to analyse the wind tunnel measurements which have been taken in the EU project 'MEXICO'. In the MEXICO project 10 institutes from 6 countries cooperated in doing experiments on an instrumented, 3 bladed wind turbine of 4.5 m diameter placed in the 9.5 by 9.5 m2 open section of the Large Low-speed Facility (LLF) of DNW in the Netherlands. Pressure distributions on the blades were obtained from 148 Kulite pressure sensors, distributed over 5 sections at 25, 35, 60, 82 and 92 % radial position respectively. Blade loads were monitored through two strain-gauge bridges at each blade root. Most interesting however are the extensive PIV flow field measurements, which have been taken simultaneously with the pressure and load measurements. As a result of the international collaboration within this task a very thorough analysis of the data could be carried out and a large number of codes were validated not only in terms of loads but also in terms of underlying flow field. The paper will present several results from Mexnext-I, i.e. validation results and conclusion on modelling deficiencies and directions for model improvement. The future plans of the Mexnext consortium are also briefly discussed. Amongst these are Mexnext-II, a project in which also aerodynamic measurements other than MEXICO are included, and 'New MEXICO' in which additional measurement on the MEXICO model are performed.

Optimising the Collaborative Practice of Nurses in Primary Care Settings Using a Knowledge Translation Approach

ERIC Educational Resources Information Center

Oelke, Nelly; Wilhelm, Amanda; Jackson, Karen

2016-01-01

The role of nurses in primary care is poorly understood and many are not working to their full scope of practice. Building on previous research, this knowledge translation (KT) project's aim was to facilitate nurses' capacity to optimise their practice in these settings. A Summit engaging Alberta stakeholders in a deliberative discussion was the…

Optimisation of Critical Infrastructure Protection: The SiVe Project on Airport Security

NASA Astrophysics Data System (ADS)

Breiing, Marcus; Cole, Mara; D'Avanzo, John; Geiger, Gebhard; Goldner, Sascha; Kuhlmann, Andreas; Lorenz, Claudia; Papproth, Alf; Petzel, Erhard; Schwetje, Oliver

This paper outlines the scientific goals, ongoing work and first results of the SiVe research project on critical infrastructure security. The methodology is generic while pilot studies are chosen from airport security. The outline proceeds in three major steps, (1) building a threat scenario, (2) development of simulation models as scenario refinements, and (3) assessment of alternatives. Advanced techniques of systems analysis and simulation are employed to model relevant airport structures and processes as well as offences. Computer experiments are carried out to compare and optimise alternative solutions. The optimality analyses draw on approaches to quantitative risk assessment recently developed in the operational sciences. To exploit the advantages of the various techniques, an integrated simulation workbench is build up in the project.

The effect of blade pitch in the rotor hydrodynamics of a cross-flow turbine

NASA Astrophysics Data System (ADS)

Somoano, Miguel; Huera-Huarte, Francisco

2016-11-01

In this work we will show how the hydrodynamics of the rotor of a straight-bladed Cross-Flow Turbine (CFT) are affected by the Tip Speed Ratio (TSR), and the blade pitch angle imposed to the rotor. The CFT model used in experiments consists of a three-bladed (NACA-0015) vertical axis turbine with a chord (c) to rotor diameter (D) ratio of 0.16. Planar Digital Particle Image Velocimetry (DPIV) was used, with the laser sheet aiming at the mid-span of the blades, illuminating the inner part of the rotor and the near wake of the turbine. Tests were made by forcing the rotation of the turbine with a DC motor, which provided precise control of the TSR, while being towed in a still-water tank at a constant Reynolds number of 61000. A range of TSRs from 0.7 to 2.3 were covered for different blade pitches, ranging from 8° toe-in to 16° toe-out. The interaction between the blades in the rotor will be discussed by examining dimensionless phase-averaged vorticity fields in the inner part of the rotor and mean velocity fields in the near wake of the turbine. Supported by the Spanish Ministry of Economy and Competitiveness, Grant BES-2013-065366 and project DPI2015-71645-P.

High-fidelity Modeling of Local Effects of Damage for Derated Offshore Wind Turbines

NASA Astrophysics Data System (ADS)

Richards, Phillip W.; Griffith, D. Todd; Hodges, Dewey H.

2014-06-01

Offshore wind power production is an attractive clean energy option, but the difficulty of access can lead to expensive and rare opportunities for maintenance. As part of the Structural Health and Prognostics Management (SHPM) project at Sandia National Laboratories, smart loads management (controls) are investigated for their potential to increase the fatigue life of offshore wind turbine rotor blades. Derating refers to altering the rotor angular speed and blade pitch to limit power production and loads on the rotor blades. High- fidelity analysis techniques like 3D finite element modeling (FEM) should be used alongside beam models of wind turbine blades to characterize these control strategies in terms of their effect to mitigate fatigue damage and extend life of turbine blades. This study will consider a commonly encountered damage type for wind turbine blades, the trailing edge disbond, and show how FEM can be used to quantify the effect of operations and control strategies designed to extend the fatigue life of damaged blades. The Virtual Crack Closure Technique (VCCT) will be used to post-process the displacement and stress results to provide estimates of damage severity/criticality and provide a means to estimate the fatigue life under a given operations and control strategy.

Fluid-structure coupling for wind turbine blade analysis using OpenFOAM

NASA Astrophysics Data System (ADS)

Dose, Bastian; Herraez, Ivan; Peinke, Joachim

2015-11-01

Modern wind turbine rotor blades are designed increasingly large and flexible. This structural flexibility represents a problem for the field of Computational Fluid Dynamics (CFD), which is used for accurate load calculations and detailed investigations of rotor aerodynamics. As the blade geometries within CFD simulations are considered stiff, the effect of blade deformation caused by aerodynamic loads cannot be captured by the common CFD approach. Coupling the flow solver with a structural solver can overcome this restriction and enables the investigation of flexible wind turbine blades. For this purpose, a new Finite Element (FE) solver was implemented into the open source CFD code OpenFOAM. Using a beam element formulation based on the Geometrically Exact Beam Theory (GEBT), the structural model can capture geometric non-linearities such as large deformations. Coupled with CFD solvers of the OpenFOAM package, the new framework represents a powerful tool for aerodynamic investigations. In this work, we investigated the aerodynamic performance of a state of the art wind turbine. For different wind speeds, aerodynamic key parameters are evaluated and compared for both, rigid and flexible blade geometries. The present work is funded within the framework of the joint project Smart Blades (0325601D) by the German Federal Ministry for Economic Affairs and Energy (BMWi) under decision of the German Federal Parliament.

Analytical design of an advanced radial turbine. [automobile engines

NASA Technical Reports Server (NTRS)

Large, G. D.; Finger, D. G.; Linder, C. G.

1981-01-01

The aerodynamic and mechanical potential of a single stage ceramic radial inflow turbine was evaluated for a high temperature single stage automotive engine. The aerodynamic analysis utilizes a turbine system optimization technique to evaluate both radial and nonradial rotor blading. Selected turbine rotor configurations were evaluated mechanically with three dimensional finite element techniques. Results indicate that exceptionally high rotor tip speeds (2300 ft/sec) and performance potential are feasible with radial bladed rotors if the projected ceramic material properties are realized. Nonradial rotors reduced tip speed requirements (at constant turbine efficiency) but resulted in a lower cumulative probability of success due to higher blade and disk stresses.

Part 1 - Experimental study of the pressure fluctuations on propeller turbine runner blades during steady-state operation

NASA Astrophysics Data System (ADS)

Houde, S.; Fraser, R.; Ciocan, G. D.; Deschênes, C.

2012-11-01

A good evaluation of the unsteady pressure field on hydraulic turbine blades is critical in evaluating the turbine lifespan and its maintenance schedule. Low-head turbines such as Kaplan and Propeller, using a relatively low number of blades supported only at the hub, may also undergo significant deflections at the blade tips which will lead to higher amplitude vibration compared to Francis turbines. Furthermore, the precise evaluation of the unsteady pressure distribution on low-head turbines is still a challenge for computational fluid dynamics (CFD). Within the framework of an international research consortium on low-head turbines, a research project was instigated at the Hydraulic Machines Laboratory in Laval University (LAMH) to perform experimental measurements of the unsteady pressure field on propeller turbine model runner blades. The main objective of the project was to measure the pressure fluctuations on a wide band of frequencies, both in a blade-to-blade channel and on the pressure and suction side of the same blade, to provide validation data for CFD computations. To do so, a 32 channels telemetric data transmission system was used to extract the signal of 31 pressure transducers and two strain gages from the rotating part at an acquisition frequency of 5 KHz. The miniature piezoelectric pressure transducers were placed on two adjacent runner blades according to an estimated pressure distribution coming from flow simulations. Two suction sides and one pressure side were instrumented. The strain gages were mounted in full-bridge on both pressure and suction sides to measure the blade span wise deflection. In order to provide boundary conditions for flow simulations, the test bench conditions during the measurements were acquired. The measurements were made in different operating conditions ranging from part load, where a cavitating vortex occurs, to full load under different heads. The results enabled the identification and the quantification of the major known sources of pressure fluctuation as well as some unexpected ones. The paper first presents the experimental methodology discussing relevant topics such as telemetric system setup, transducers calibration and errors analysis. The main results are then presented to illustrate the relative amplitude of the main source of pressure fluctuations under different operating conditions. The discussion and conclusion addresses the important observations stemming from the data analysis and illustrates that most of the results can be correlated with the known behavior of hydraulic turbines while some require further investigation.

Structural health monitoring of wind turbine blades : SE 265 Final Project.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barkley, W. C.; Jacobs, Laura D.; Rutherford, A. C.

2006-03-23

ACME Wind Turbine Corporation has contacted our dynamic analysis firm regarding structural health monitoring of their wind turbine blades. ACME has had several failures in previous years. Examples are shown in Figure 1. These failures have resulted in economic loss for the company due to down time of the turbines (lost revenue) and repair costs. Blade failures can occur in several modes, which may depend on the type of construction and load history. Cracking and delamination are some typical modes of blade failure. ACME warranties its turbines and wishes to decrease the number of blade failures they have to repairmore » and replace. The company wishes to implement a real time structural health monitoring system in order to better understand when blade replacement is necessary. Because of warranty costs incurred to date, ACME is interested in either changing the warranty period for the blades in question or predicting imminent failure before it occurs. ACME's current practice is to increase the number of physical inspections when blades are approaching the end of their fatigue lives. Implementation of an in situ monitoring system would eliminate or greatly reduce the need for such physical inspections. Another benefit of such a monitoring system is that the life of any given component could be extended since real conditions would be monitored. The SHM system designed for ACME must be able to operate while the wind turbine is in service. This means that wireless communication options will likely be implemented. Because blade failures occur due to cyclic stresses in the blade material, the sensing system will focus on monitoring strain at various points.« less

Attitude Dynamics, Stability, and Control of a Heliogyro Solar Sail

NASA Astrophysics Data System (ADS)

Pimienta-Penalver, Adonis Reinier

A heliogyro solar sail concept, dubbed `HELIOS', is proposed as an alternative to deep space missions without the need for on-board propellant. Although this type of solar sail has existed in concept for several decades, and some previous studies have investigated certain aspects of its operation, a significant amount of research is still needed to analyze the dynamic and control characteristics of the structure under the projected range of orbital conditions. This work presents an improvement upon the existing discrete-mass models of the heliogyro blade, and the extension of its application from a single membrane blade to a fully-coupled approximation of the dynamics of the HELIOS system with multiple spinning membrane blades around a central hub. The incorporation of structural stiffness and external forcing effects into the model is demonstrated to add a further degree of fidelity in simulating the stability properties of the system. Additionally, the approximated dynamics of multiple-blade heliogyro structures are examined under the effect of solar radiation pressure. Lastly, this study evaluates a control algorithm at each blade root to impose structural integrity and attitude control by coordinating well-known helicopter blade pitching profiles.

Tip vortices in the actuator line model

NASA Astrophysics Data System (ADS)

Martinez, Luis; Meneveau, Charles

2017-11-01

The actuator line model (ALM) is a widely used tool to represent the wind turbine blades in computational fluid dynamics without the need to resolve the full geometry of the blades. The ALM can be optimized to represent the `correct' aerodynamics of the blades by choosing an appropriate smearing length scale ɛ. This appropriate length scale creates a tip vortex which induces a downwash near the tip of the blade. A theoretical frame-work is used to establish a solution to the induced velocity created by a tip vortex as a function of the smearing length scale ɛ. A correction is presented which allows the use of a non-optimal smearing length scale but still provides the downwash which would be induced using the optimal length scale. Thanks to the National Science Foundation (NSF) who provided financial support for this research via Grants IGERT 0801471, IIA-1243482 (the WINDINSPIRE project) and ECCS-1230788.

Spreading granular material with a blade

NASA Astrophysics Data System (ADS)

Dressaire, Emilie; Singh, Vachitar; Grimaldi, Emma; Sauret, Alban

2015-11-01

The spreading of a complex fluid with a blade is encountered in applications that range from the bulldozing of granular material in construction projects to the coating of substrates with fluids in industrial applications. This spreading process is also present in everyday life, when we use a knife to turn a lump of peanut butter into a thin layer over our morning toast. In this study, we rely on granular media in a model experiment to describe the three-dimensional spreading of the material. Our experimental set-up allows tracking the spreading of a sandpile on a translating flat surface as the blade remains fixed. We characterize the spreading dynamics and the shape of the spread fluid layer when varying the tilt of the blade, its spacing with the surface and its speed. Our findings suggest that it is possible to tune the spreading parameters to optimize the coating.

Project Boomerang

ERIC Educational Resources Information Center

King, Allen L.

1975-01-01

Describes an experimental project on boomerangs designed for an undergraduate course in classical mechanics. The students designed and made their own boomerangs, devised their own procedures, and carried out suitable measurements. Presents some of their data and a simple analysis for the two-bladed boomerang. (Author/MLH)

Slicing of silicon into sheet material. Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project. Third quarterly report, September 20, 1976--December 19, 1976

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holden, S.C.

1976-12-27

The stability of tensioned blades used in multiblade sawing does not seem to be the limitation in cutting with thin blades. So far, 0.010 cm thick blades have been totally unsuccessful. Recently, 0.015 cm blades have proven successful in wafering, offering an 0.005 cm reduction in the silicon used per slice. The failure of thin blades is characterized as a possible result of blade misalignment or from the inherent uncontrollability of the loose abrasive multiblade process. Corrective procedures will be employed in the assembly of packages to eliminate one type of blade misalignment. Two ingots were sliced with the samemore » batch of standard silicon carbide abrasive slurry to determine the useful lifetime of this expendable material. After 250 slices, the cutting efficiency had not degraded. Further tests will be continued to establish the maximum lifetime of both silicon carbide and boron carbide abrasive. Electron microscopy will be employed to evaluate the wear of abrasive particles in the failure of abrasive slurry. The surface damage of silicon wafers has been characterized as predominantly subsurface fracture. Damage with No. 600 SiC is between 10 and 15 microns into the wafer surface. This agrees well with previous investigations of damage from silicon carbide abrasive papers.« less

Understanding ageing in older Australians: The contribution of the Dynamic Analyses to Optimise Ageing (DYNOPTA) project to the evidenced base and policy

PubMed Central

Anstey, Kaarin J; Bielak, Allison AM; Birrell, Carole L; Browning, Colette J; Burns, Richard A; Byles, Julie; Kiley, Kim M; Nepal, Binod; Ross, Lesley A; Steel, David; Windsor, Timothy D

2014-01-01

Aim To describe the Dynamic Analyses to Optimise Ageing (DYNOPTA) project and illustrate its contributions to understanding ageing through innovative methodology, and investigations on outcomes based on the project themes. DYNOPTA provides a platform and technical expertise that may be used to combine other national and international datasets. Method The DYNOPTA project has pooled and harmonized data from nine Australian longitudinal studies to create the largest available longitudinal dataset (N=50652) on ageing in Australia. Results A range of findings have resulted from the study to date, including methodological advances, prevalence rates of disease and disability, and mapping trajectories of ageing with and without increasing morbidity. DYNOPTA also forms the basis of a microsimulation model that will provide projections of future costs of disease and disability for the baby boomer cohort. Conclusion DYNOPTA contributes significantly to the Australian evidence-base on ageing to inform key social and health policy domains. PMID:22032767

Comparison of Computational-Model and Experimental-Example Trained Neural Networks for Processing Speckled Fringe Patterns

NASA Technical Reports Server (NTRS)

Decker, A. J.; Fite, E. B.; Thorp, S. A.; Mehmed, O.

1998-01-01

The responses of artificial neural networks to experimental and model-generated inputs are compared for detection of damage in twisted fan blades using electronic holography. The training-set inputs, for this work, are experimentally generated characteristic patterns of the vibrating blades. The outputs are damage-flag indicators or second derivatives of the sensitivity-vector-projected displacement vectors from a finite element model. Artificial neural networks have been trained in the past with computational-model-generated training sets. This approach avoids the difficult inverse calculations traditionally used to compare interference fringes with the models. But the high modeling standards are hard to achieve, even with fan-blade finite-element models.

Comparison of Computational, Model and Experimental, Example Trained Neural Networks for Processing Speckled Fringe Patterns

NASA Technical Reports Server (NTRS)

Decker, A. J.; Fite, E. B.; Thorp, S. A.; Mehmed, O.

1998-01-01

The responses of artificial neural networks to experimental and model-generated inputs are compared for detection of damage in twisted fan blades using electronic holography. The training-set inputs, for this work, are experimentally generated characteristic patterns of the vibrating blades. The outputs are damage-flag indicators or second derivatives of the sensitivity-vector-projected displacement vectors from a finite element model. Artificial neural networks have been trained in the past with computational-model- generated training sets. This approach avoids the difficult inverse calculations traditionally used to compare interference fringes with the models. But the high modeling standards are hard to achieve, even with fan-blade finite-element models.

Slicing of silicon into sheet material: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Holden, S. C.

1976-01-01

Multiblade slurry sawing is used to slice 10 cm diameter silicon ingots into wafers 0.024 cm thick using 0.050 cm of silicon per slice (0.026 cm kerf loss). Total slicing time is less than twenty hours, and 143 slices are produced simultaneously. Productivity (slice area per hour per blade) is shown as a function or blade load and thickness, and abrasive size. Finer abrasive slurries cause a reduction in slice productivity, and thin blades cause a reduction of wafer accuracy. Sawing induced surface damage is found to extend 18 microns into the wafer.

Radiation Dose Assessment for Military Personnel of the Enewetak Atoll Cleanup Project (1977-1980)

DTIC Science & Technology

2018-04-13

population are detailed. 2.1 Enewetak Atoll Setting Enewetak Atoll (Figure 2) is approximately 23 by 17 statute miles with the long axis running ...Survey and stake the boundaries of soil excision areas; • Remove excess brush; • Excise (scrape surface with bulldozer blade ) the area and...JTGJ-2 and FRST members Survey instruments, soil sampling tools, dump trucks, bucket and backhoe loaders, water tank trucks, scrape blades

Alternative blade materials for technical and ecological optimization of a hydraulic pressure machine

NASA Astrophysics Data System (ADS)

Schwyzer, Olivier; Saenger, Nicole

2016-11-01

The Hydraulic Pressure Machine (HPM) is an energy converter to exploit head differences between 0.5 and 2.5 m in small streams and irrigation canals. Previous investigations show that efficiencies above 60% are possible. Several case studies indicate good continuity for aquatic life (e.g. fish) and bed load for the technology. The technology is described as an economically and ecologically viable option for small scale hydropower generation. Primary goal of this research is to improve the HPM blade design regarding its continuity properties by maintaining good efficiency rates. This is done by modifying the blade tip and testing within a large physical model under laboratory condition. Blade tips from steel (conventional - reference case) and a combination of EPDM rubber and steel as sandwich construction (rubber, steel, rubber - adhesive layered) are tested and compared. Both materials reach similar values for hydraulic efficiency (approx. 58%) and mechanical power output (approx. 220 W). The variation of different gap sizes pointed out the importance of small clearance gaps to reach high efficiencies. For assessing the two blade tip materials regarding continuity for aquatic life, fish dummies were led through the wheel. Analysis of slow motion video of dummies hit by the blade show significant advantages for the EPDM blade tip. The EPDM rubber allows to bend and thus reduces the shock and the probability for cuts on the fish dummy. It was shown that blade tips from EPDM have certain advantages regarding continuity compared to standard blade tips from steel. No compromise regarding energy production had to be made. These results from the HPM can be transferred to breast shot water wheel and may be applied for new and retrofitting projects.

Coolant Density and Control Blade History Effects in Extended BWR Burnup Credit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ade, Brian J; Marshall, William BJ J; Bowman, Stephen M

2015-01-01

Oak Ridge National Laboratory and the US Nuclear Regulatory Commission have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase investigates the applicability of peak reactivity methods currently used for spent fuel pools to spent fuel storage and transportation casks and the validation of reactivity (k eff) calculations and predicted spent fuel compositions. The second phase focuses on extending BUC beyond peak reactivity. This paper documents work performed to date investigating some aspects of extended BUC. (The technicalmore » basis for application of peak reactivity methods to BWR fuel in storage and transportation systems is presented in a companion paper.) Two reactor operating parameters are being evaluated to establish an adequate basis for extended BWR BUC: (1) the effect of axial void profile and (2) the effect of control blade utilization during operation. A detailed analysis of core simulator data for one cycle of a modern operating BWR plant was performed to determine the range of void profiles and the variability of the profile experienced during irradiation. Although a single cycle does not provide complete data, the data obtained are sufficient to determine the primary effects and to identify conservative modeling approaches. These data were used in a study of the effect of axial void profile. The first stage of the study was determination of the necessary moderator density temporal fidelity in depletion modeling. After the required temporal fidelity was established, multiple void profiles were used to examine the effect on cask reactivity. The results of these studies are being used to develop recommendations for conservatively modeling the void profile effects for BWR depletion calculations. The second operational parameter studied was control blade history. Control blades are inserted in various locations and at varying degrees during BWR operation based on the core loading pattern. When present during depletion, control blades harden the neutron spectrum locally because they displace the moderator and absorb thermal neutrons. The investigation of the effect of control blades on post operational cask reactivity is documented herein, as is the effect of multiple (continuous and intermittent) exposure periods with control blades inserted. The coupled effects of control blade presence on power density, void profile, or burnup profile will be addressed in future work.« less

Optimisation of the vibrational response of ultrasonic cutting systems

NASA Astrophysics Data System (ADS)

Cartmell, M. P.; Lim, F. C. N.; Cardoni, A.; Lucas, M.

2005-10-01

This paper provides an account of an investigation into possible dynamic interactions between two coupled non-linear sub-systems, each possessing opposing non-linear overhang characteristics in the frequency domain in terms of positive and negative cubic stiffnesses. This system is a two-degree-of-freedom Duffing oscillator in which certain non-linear effects can be advantageously neutralised under specific conditions. This theoretical vehicle has been used as a preliminary methodology for understanding the interactive behaviour within typical industrial ultrasonic cutting components. Ultrasonic energy is generated within a piezoelectric exciter, which is inherently non-linear, and which is coupled to a bar- or block-horn, and to one or more material cutting blades, for example. The horn/blade configurations are also non-linear, and within the whole system there are response features which are strongly reminiscent of positive and negative cubic stiffness effects. The two-degree-of-freedom model is analysed and it is shown that a practically useful mitigating effect on the overall non-linear response of the system can be created under certain conditions when one of the cubic stiffnesses is varied. It has also been shown experimentally that coupling of ultrasonic components with different non-linear characteristics can strongly influence the performance of the system and that the general behaviour of the hypothetical theoretical model is indeed borne out in practice. Further experiments have shown that a multiple horn/blade configuration can, under certain circumstances, display autoparametric responses based on the forced response of the desired longitudinal mode parametrically exciting an undesired lateral mode. Typical autoparametric response phenomena have been observed and are presented at the end of the paper.

Accessible high performance computing solutions for near real-time image processing for time critical applications

NASA Astrophysics Data System (ADS)

Bielski, Conrad; Lemoine, Guido; Syryczynski, Jacek

2009-09-01

High Performance Computing (HPC) hardware solutions such as grid computing and General Processing on a Graphics Processing Unit (GPGPU) are now accessible to users with general computing needs. Grid computing infrastructures in the form of computing clusters or blades are becoming common place and GPGPU solutions that leverage the processing power of the video card are quickly being integrated into personal workstations. Our interest in these HPC technologies stems from the need to produce near real-time maps from a combination of pre- and post-event satellite imagery in support of post-disaster management. Faster processing provides a twofold gain in this situation: 1. critical information can be provided faster and 2. more elaborate automated processing can be performed prior to providing the critical information. In our particular case, we test the use of the PANTEX index which is based on analysis of image textural measures extracted using anisotropic, rotation-invariant GLCM statistics. The use of this index, applied in a moving window, has been shown to successfully identify built-up areas in remotely sensed imagery. Built-up index image masks are important input to the structuring of damage assessment interpretation because they help optimise the workload. The performance of computing the PANTEX workflow is compared on two different HPC hardware architectures: (1) a blade server with 4 blades, each having dual quad-core CPUs and (2) a CUDA enabled GPU workstation. The reference platform is a dual CPU-quad core workstation and the PANTEX workflow total computing time is measured. Furthermore, as part of a qualitative evaluation, the differences in setting up and configuring various hardware solutions and the related software coding effort is presented.

Laser Displacement Measurements of Fan Blades in Resonance and Flutter During the Boundary Layer Ingesting Inlet and Distortion-Tolerant Fan Test

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.; Provenza, Andrew J.; Bakhle, Milind A.; Min, James B.; Abdul-Aziz, Ali

2018-01-01

NASA's Advanced Air Transport Technology Project is investigating boundary layer ingesting propulsors for future subsonic commercial aircraft to improve aircraft efficiency, thereby reducing fuel burn. To that end, a boundary layer ingesting inlet and distortion-tolerant fan stage was designed, fabricated, and tested within the 8' x 6' Supersonic Wind Tunnel at NASA Glenn Research Center. Because of the distortion in the air flow over the fan, the blades were designed to withstand a much higher aerodynamic forcing than for a typical clean flow. The blade response for several resonance modes were measured during start-up and shutdown, as well as at near 85% design speed. Flutter in the first bending mode was also observed in the fan at the design speed, at an off-design condition, although instabilities were difficult to instigate with this fan in general. Blade vibrations were monitored through twelve laser displacement probes that were placed around the inner circumference of the casing, at the blade leading and trailing edges. These probes captured the movement of all the blades during the entire test. Results are presented for various resonance mode amplitudes, frequencies and damping, as well as flutter amplitudes and frequency. Benefits and disadvantages of laser displacement probe measurements versus strain gage measurements are discussed.

Scope of wind energy in Bangladesh and simulation analysis of three different horizontal axis wind turbine blade shapes

NASA Astrophysics Data System (ADS)

Khan, Md. Arif-Ul Islam; Das, Swapnil; Dey, Saikat

2017-12-01

: Economic growth and energy demand are intertwined. Therefore, one of the most important concerns of the government and in the world is the need for energy security. Currently, the world relies on coal, crude oil and natural gas for energy generati on. However, the energy crisis together with climate change and depletion of oil have become major concerns to all countries. Therefore, alternative energy resources such as wind energy attracted interest from both public and private sectors to invest in energy generation from this source extensively. Both Vertical and Horizontal axis wind turbine can be used for this purpose. But, Horizontal axis is the most promising between them due to its efficiency and low expense. Bangladesh being a tropical country does have a lot of wind flow at different seasons of the year. However, there are some windy locations in which wind energy projects could be feasible. In this project a detailed review of the current st ate-of-art for wind turbine blade design is presented including theoretical maximum efficiency, Horizontal Axis Wind Turbine (HAWT) blade design, simulation power and COP values for different blade material. By studying previously collected data on the wind resources available in B angladesh at present and by analyzing this data, this paper will discuss the scope of wind energy in Bangladesh.

Materials Processes (MP) Engineering Internship Projects

NASA Technical Reports Server (NTRS)

Tomsik, Elizabeth

2017-01-01

This poster illustrates my major and minor projects worked on during my entire time interning at KSC in the Materials Science Branch. My major projects consist of three Failure Analyses, a research project on Magnesium Alloys, and the manufacturing and mechanical testing of the Advanced Plant Habitat. My three Failure Analyses are Umbilical Testing Ground Plates, Lithium Ion Battery Locking Spring Blade, and a Liquid Oxygen Poppet.

Airfoil family design for large offshore wind turbine blades

NASA Astrophysics Data System (ADS)

Méndez, B.; Munduate, X.; San Miguel, U.

2014-06-01

Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The EOLIA project 2007-2010 (Spanish Goverment funded project) was focused on the design of large offshore wind turbines for deep waters. The project was managed by ACCIONA Energia and the wind turbine technology was designed by ACCIONA Windpower. The project included the design of a wind turbine airfoil family especially conceived for large offshore wind turbine blades, in the order of 5MW machine. Large offshore wind turbines suffer high extreme loads due to their size, in addition the lack of noise restrictions allow higher tip speeds. Consequently, the airfoils presented in this work are designed for high Reynolds numbers with the main goal of reducing blade loads and mantainig power production. The new airfoil family was designed in collaboration with CENER (Spanish National Renewable Energy Centre). The airfoil family was designed using a evolutionary algorithm based optimization tool with different objectives, both aerodynamic and structural, coupled with an airfoil geometry generation tool. Force coefficients of the designed airfoil were obtained using the panel code XFOIL in which the boundary layer/inviscid flow coupling is ineracted via surface transpiration model. The desing methodology includes a novel technique to define the objective functions based on normalizing the functions using weight parameters created from data of airfoils used as reference. Four airfoils have been designed, here three of them will be presented, with relative thickness of 18%, 21%, 25%, which have been verified with the in-house CFD code, Wind Multi Block WMB, and later validated with wind tunnel experiments. Some of the objectives for the designed airfoils concern the aerodynamic behavior (high efficiency and lift, high tangential coefficient, insensitivity to rough conditions, etc.), others concern the geometry (good for structural design, compatibility for the different airfoil family members, etc.) and with the ultimate objective that the airfoils will reduce the blade loads. In this paper the whole airfoil design process and the main characteristics of the airfoil family are described. Some force coefficients for the design Reynolds number are also presented. The new designed airfoils have been studied with computational calculations (panel method code and CFD) and also in a wind tunnel experimental campaign. Some of these results will be also presented in this paper.

Case Study and Numerical Analysis of Vibration and Runner Cracks for the Lipno I Hydroelectric Project

NASA Astrophysics Data System (ADS)

Zouhar, J.; Obrovsky, J.; Feilhauer, M.; Skotak, A.

2016-11-01

The refurbishment of the Lipno I TG2 Francis turbine, situated on River Vltava, with maximum net head of 165 m and required operational range from 0 to 67MW of turbine power was performed in 2014. The new hydraulic design of the spiral case, distributor and runner was developed for this project. After about 1000 hours of operation the site inspection was performed and the cracks were found on 8 runner blades of 17 blades altogether. The all cracks were found near runner hub beginning from the trailing edge. The dimensions of the cracks were different with maximum length of 123 mm and minimum length of 3 mm. The runner was repaired and the intensive investigation was started to define the main cause of the cracks creation and to determine the measures for their elimination. This paper presents the program of this investigation which consists of static and dynamic blade strain measurement, CFD and FEM analysis, discusses the crack causes and overview the solution how to return the turbine successfully to operation.

The Effect of Mounting Vortex Generators on the DTU 10MW Reference Wind Turbine Blade

NASA Astrophysics Data System (ADS)

Skrzypiński, Witold; Gaunaa, Mac; Bak, Christian

2014-06-01

The aim of the current work is to analyze possible advantages of mounting Vortex Generators (VG's) on a wind turbine blade. Specifically, the project aims at investigating at which radial sections of the DTU 10 MW Reference Wind Turbine blade it is most beneficial to mount the VG's in order to increase the Annual Energy Production (AEP) under realistic conditions. The present analysis was carried out in several steps: (1) The clean two dimensional airfoil characteristics were first modified to emulate the effect of all possible combinations of VG's (1% high at suction side x/c=0.2-0.25) and two Leading Edge Roughness (LER) values along the whole blade span. (2) The combinations from Step 1, including the clean case were subsequently modified to take into account three dimensional effects. (3) BEM computations were carried out to determine the aerodynamic rotor performance using each of the datasets from Step 2 along the whole blade span for all wind speeds in the turbine control scheme. (4) Employing the assumption of radial independence between sections of the blades, and using the results of the BEM computations described in Step 3, it is possible to determine for each radial position independently whether it is beneficial to install VG's in the smooth and LER cases, respectively. The results indicated that surface roughness that corresponds to degradation of the power curve may to some extent be mitigated by installation of VG's. The present results also indicated that the optimal VG configuration in terms of maximizing AEP depends on the degree of severity of the LER. This is because, depending on the condition of blade surface, installation of VG's on an incorrect blade span or installation of VG's too far out on the blade may cause loss in AEP. The results also indicated that the worse condition of the blade surface, the more gain may be obtained from the installation of VG's.

A Novel Method for Reducing Rotor Blade-Vortex Interaction

NASA Technical Reports Server (NTRS)

Glinka, A. T.

2000-01-01

One of the major hindrances to expansion of the rotorcraft market is the high-amplitude noise they produce, especially during low-speed descent, where blade-vortex interactions frequently occur. In an attempt to reduce the noise levels caused by blade-vortex interactions, the flip-tip rotor blade concept was devised. The flip-tip rotor increases the miss distance between the shed vortices and the rotor blades, reducing BVI noise. The distance is increased by rotating an outboard portion of the rotor tip either up or down depending on the flight condition. The proposed plan for the grant consisted of a computational simulation of the rotor aerodynamics and its wake geometry to determine the effectiveness of the concept, coupled with a series of wind tunnel experiments exploring the value of the device and validating the computer model. The computational model did in fact show that the miss distance could be increased, giving a measure of the effectiveness of the flip-tip rotor. However, the wind experiments were not able to be conducted. Increased outside demand for the 7'x lO' wind tunnel at NASA Ames and low priority at Ames for this project forced numerous postponements of the tests, eventually pushing the tests beyond the life of the grant. A design for the rotor blades to be tested in the wind tunnel was completed and an analysis of the strength of the model blades based on predicted loads, including dynamic forces, was done.

Effect of vortex generators on the power conversion performance and structural dynamic loads of the Mod-2 wind turbine

NASA Technical Reports Server (NTRS)

Sullivan, T. L.

1984-01-01

Applying vortex generators from 20 to 100 percent span of the Mod-2 rotor resulted in a projected increase in annual energy capture of 20 percent and reduced the wind speed at which rated power is reached by nearly 3 m/sec. Application of vortex generators from 20 to 70 percent span, the fixed portion of the Mod-2 rotor, resulted in a projected increase in annual energy capture of about half this. This improved performance came at the cost of a small increase in cyclic blade loads in below rated power conditions. Cyclic blade loads were found to correlate well with the change in wind speed during one rotor revolution.

David Snowberg | NREL

Science.gov Websites

the management of blade test projects. He also works with the NREL Marine Hydrokinetic group in the areas of risk management and failure analysis. David is a registered Professional Engineer in Arizona within the discipline of mechanical engineering; he is also a certified Project Management Professional

Recruitment and retention. The Derby Theatre Project experience.

PubMed

Ainsworth, David

2003-10-01

The National Theatre Project was set up in March 2001 by the Modernisation Agency to improve the patient and carer experience, improve employee satisfaction, optimise theatre utilisation and reduce cancelled operations. This is the second article in the series where David Ainsworth, manager of a pilot site project in Derby, describes issues around the Theatre Project. This month the focus is on recruitment, retention and staff morale.

Strong constraint on modelled global carbon uptake using solar-induced chlorophyll fluorescence data.

PubMed

MacBean, Natasha; Maignan, Fabienne; Bacour, Cédric; Lewis, Philip; Peylin, Philippe; Guanter, Luis; Köhler, Philipp; Gómez-Dans, Jose; Disney, Mathias

2018-01-31

Accurate terrestrial biosphere model (TBM) simulations of gross carbon uptake (gross primary productivity - GPP) are essential for reliable future terrestrial carbon sink projections. However, uncertainties in TBM GPP estimates remain. Newly-available satellite-derived sun-induced chlorophyll fluorescence (SIF) data offer a promising direction for addressing this issue by constraining regional-to-global scale modelled GPP. Here, we use monthly 0.5° GOME-2 SIF data from 2007 to 2011 to optimise GPP parameters of the ORCHIDEE TBM. The optimisation reduces GPP magnitude across all vegetation types except C4 plants. Global mean annual GPP therefore decreases from 194 ± 57 PgCyr -1 to 166 ± 10 PgCyr -1 , bringing the model more in line with an up-scaled flux tower estimate of 133 PgCyr -1 . Strongest reductions in GPP are seen in boreal forests: the result is a shift in global GPP distribution, with a ~50% increase in the tropical to boreal productivity ratio. The optimisation resulted in a greater reduction in GPP than similar ORCHIDEE parameter optimisation studies using satellite-derived NDVI from MODIS and eddy covariance measurements of net CO 2 fluxes from the FLUXNET network. Our study shows that SIF data will be instrumental in constraining TBM GPP estimates, with a consequent improvement in global carbon cycle projections.

Exploring Electrical and Magnetic Resonances from Coherently Correlated Long-Lived Radical Pairs towards Development of Negative Refractive-Index Materials

DTIC Science & Technology

2015-04-29

during reporting period: Changes in research objectives (if any): Change in AFOSR Program Manager, if any: Extensions granted or milestones slipped , if...SUBTITLE TOWARDS COMBINED ACTIVE CONTROL OF FILM COOLING AND TURBINE BLADE AERODYNAMICS 5a. CONTRACT NUMBER FA9550-08-1-0440 5b. GRANT NUMBER N/A 5c...release. Project Title: Towards Combined Active Control of Film Cooling and Turbine Blade Aerodynamics. Award Number: FA9550-08-1-0440 Dates Covered

Multiple piece turbine rotor blade

DOEpatents

Jones, Russell B; Fedock, John A

2013-05-21

A multiple piece turbine rotor blade with a shell having an airfoil shape and secured between a spar and a platform with the spar including a tip end piece. a snap ring fits around the spar and abuts against the spar tip end piece on a top side and abuts against a shell on the bottom side so that the centrifugal loads from the shell is passed through the snap ring and into the spar and not through a tip cap dovetail slot and projection structure.

Optimisation of reconstruction--reprojection-based motion correction for cardiac SPECT.

PubMed

Kangasmaa, Tuija S; Sohlberg, Antti O

2014-07-01

Cardiac motion is a challenging cause of image artefacts in myocardial perfusion SPECT. A wide range of motion correction methods have been developed over the years, and so far automatic algorithms based on the reconstruction--reprojection principle have proved to be the most effective. However, these methods have not been fully optimised in terms of their free parameters and implementational details. Two slightly different implementations of reconstruction--reprojection-based motion correction techniques were optimised for effective, good-quality motion correction and then compared with each other. The first of these methods (Method 1) was the traditional reconstruction-reprojection motion correction algorithm, where the motion correction is done in projection space, whereas the second algorithm (Method 2) performed motion correction in reconstruction space. The parameters that were optimised include the type of cost function (squared difference, normalised cross-correlation and mutual information) that was used to compare measured and reprojected projections, and the number of iterations needed. The methods were tested with motion-corrupt projection datasets, which were generated by adding three different types of motion (lateral shift, vertical shift and vertical creep) to motion-free cardiac perfusion SPECT studies. Method 2 performed slightly better overall than Method 1, but the difference between the two implementations was small. The execution time for Method 2 was much longer than for Method 1, which limits its clinical usefulness. The mutual information cost function gave clearly the best results for all three motion sets for both correction methods. Three iterations were sufficient for a good quality correction using Method 1. The traditional reconstruction--reprojection-based method with three update iterations and mutual information cost function is a good option for motion correction in clinical myocardial perfusion SPECT.

Preliminary Airworthiness Evaluation AH-1S Helicopter with OGEE Tip Shape Rotor Blades

DTIC Science & Technology

1980-05-01

ENGINEER PROJECT PILOT HENRY ARNAIZ PROJECT ENGINEER DTIC MAY 1980 ELECTEV SEP 2 I8 Approved for public release; distribution unlimited. A UNITED STATES...compressibility effects between flights. 7. Airspeed and altitude were obtained from a boom-mounted pitot -static probe. Corrections for position error

Predicting full-field dynamic strain on a three-bladed wind turbine using three dimensional point tracking and expansion techniques

NASA Astrophysics Data System (ADS)

Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter

2014-03-01

As part of a project to predict the full-field dynamic strain in rotating structures (e.g. wind turbines and helicopter blades), an experimental measurement was performed on a wind turbine attached to a 500-lb steel block and excited using a mechanical shaker. In this paper, the dynamic displacement of several optical targets mounted to a turbine placed in a semi-built-in configuration was measured by using three-dimensional point tracking. Using an expansion algorithm in conjunction with a finite element model of the blades, the measured displacements were expanded to all finite element degrees of freedom. The calculated displacements were applied to the finite element model to extract dynamic strain on the surface as well as within the interior points of the structure. To validate the technique for dynamic strain prediction, the physical strain at eight locations on the blades was measured during excitation using strain-gages. The expansion was performed by using both structural modes of an individual cantilevered blade and using modes of the entire structure (three-bladed wind turbine and the fixture) and the predicted strain was compared to the physical strain-gage measurements. The results demonstrate the ability of the technique to predict full-field dynamic strain from limited sets of measurements and can be used as a condition based monitoring tool to help provide damage prognosis of structures during operation.

Slicing of silicon into sheet material. Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Holden, S. C.; Fleming, J. R.

1978-01-01

Fabrication of a prototype large capacity multiple blade slurry saw is considered. Design of the bladehead which will tension up to 1000 blades, and cut a 45 cm long silicon ingot as large as 12 cm in diameter is given. The large blade tensioning force of 270,000 kg is applied through two bolts acting on a pair of scissor toggles, significantly reducing operator set-up time. Tests with an upside-down cutting technique resulted in 100% wafering yields and the highest wafer accuracy yet experienced with MS slicing. Variations in oil and abrasives resulted only in degraded slicing results. A technique of continuous abrasive slurry separation to remove silicon debris is described.

Design study of prestressed rotor spar concept

NASA Technical Reports Server (NTRS)

Gleich, D.

1980-01-01

Studies on the Bell Helicopter 540 Rotor System of the AH-1G helicopter were performed. The stiffness, mass and geometric configurations of the Bell blade were matched to give a dynamically similar prestressed composite blade. A multi-tube, prestressed composite spar blade configuration was designed for superior ballistic survivability at low life cycle cost. The composite spar prestresses, imparted during fabrication, are chosen to maintain compression in the high strength cryogenically stretchformed 304-L stainless steel liner and tension in the overwrapped HTS graphite fibers under operating loads. This prestressing results in greatly improved crack propagation and fatigue resistance as well as enhanced fiber stiffness properties. Advantages projected for the prestressed composite rotor spar concept include increased operational life and improved ballistic survivability at low life cycle cost.

A new web-based modelling tool (Websim-MILQ) aimed at optimisation of thermal treatments in the dairy industry.

PubMed

Schutyser, M A I; Straatsma, J; Keijzer, P M; Verschueren, M; De Jong, P

2008-11-30

In the framework of a cooperative EU research project (MILQ-QC-TOOL) a web-based modelling tool (Websim-MILQ) was developed for optimisation of thermal treatments in the dairy industry. The web-based tool enables optimisation of thermal treatments with respect to product safety, quality and costs. It can be applied to existing products and processes but also to reduce time to market for new products. Important aspects of the tool are its user-friendliness and its specifications customised to the needs of small dairy companies. To challenge the web-based tool it was applied for optimisation of thermal treatments in 16 dairy companies producing yoghurt, fresh cream, chocolate milk and cheese. Optimisation with WebSim-MILQ resulted in concrete improvements with respect to risk of microbial contamination, cheese yield, fouling and production costs. In this paper we illustrate the use of WebSim-MILQ for optimisation of a cheese milk pasteurisation process where we could increase the cheese yield (1 extra cheese for each 100 produced cheeses from the same amount of milk) and reduced the risk of contamination of pasteurised cheese milk with thermoresistent streptococci from critical to negligible. In another case we demonstrate the advantage for changing from an indirect to a direct heating method for a UHT process resulting in 80% less fouling, while improving product quality and maintaining product safety.

Defining a quantitative framework for evaluation and optimisation of the environmental impacts of mega-event projects.

PubMed

Parkes, Olga; Lettieri, Paola; Bogle, I David L

2016-02-01

This paper presents a novel quantitative methodology for the evaluation and optimisation of the environmental impacts of the whole life cycle of a mega-event project: construction and staging the event and post-event site redevelopment and operation. Within the proposed framework, a mathematical model has been developed that takes into account greenhouse gas (GHG) emissions resulting from use of transportation fuel, energy, water and construction materials used at all stages of the mega-event project. The model is applied to a case study - the London Olympic Park. Three potential post-event site design scenarios of the Park have been developed: Business as Usual (BAU), Commercial World (CW) and High Rise High Density (HRHD). A quantitative summary of results demonstrates that the highest GHG emissions associated with the actual event are almost negligible compared to those associated with the legacy phase. The highest share of emissions in the legacy phase is attributed to embodied emissions from construction materials (almost 50% for the BAU and HRHD scenarios) and emissions resulting from the transportation of residents, visitors and employees to/from the site (almost 60% for the CW scenario). The BAU scenario is the one with the lowest GHG emissions compared to the other scenarios. The results also demonstrate how post-event site design scenarios can be optimised to minimise the GHG emissions. The overall outcomes illustrate how the proposed framework can be used to support decision making process for mega-event projects planning. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Learning from Lessons: Studying the Structure and Construction of Mathematics Teacher Knowledge in Australia, China and Germany

ERIC Educational Resources Information Center

Chan, Man Ching Esther; Clarke, David J.; Clarke, Doug M.; Roche, Anne; Cao, Yiming; Peter-Koop, Andrea

2018-01-01

The major premise of this project is that teachers learn from the act of teaching a lesson. Rather than asking "What must a teacher already know in order to practice effectively?", this project asks "What might a teacher learn through their activities in the classroom and how might this learning be optimised?" In this project,…

2007 NASA Seal/Secondary Air System Workshop. Volume 1

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.; Hendricks, Robert C.; Delgado, Irebert

2008-01-01

The 2007 NASA Seal/Secondary Air System workshop covered the following topics: (i) Overview of NASA's new Orion project aimed at developing a new spacecraft that will fare astronauts to the International Space Station, the Moon, Mars, and beyond; (ii) Overview of NASA's fundamental aeronautics technology project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA's turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing seal leakage as well as high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Turbine seal development topics covered include a method for fast-acting HPT blade tip clearance control, noncontacting low-leakage seals, intershaft seals, and a review of engine seal performance requirements for current and future Army engine platforms.

2008 NASA Seal/Secondary Air System Workshop

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor); Delgado, Irebert R. (Editor)

2009-01-01

The 2008 NASA Seal/Secondary Air System Workshop covered the following topics: (i) Overview of NASA s new Orion project aimed at developing a new spacecraft that will fare astronauts to the International Space Station, the Moon, Mars, and beyond; (ii) Overview of NASA s fundamental aeronautics technology project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA s turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing seal leakage as well as high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Turbine seal development topics covered include a method for fast-acting HPT blade tip clearance control, noncontacting low-leakage seals, intershaft seals, and a review of engine seal performance requirements for current and future Army engine platforms.

New Set of Fan Blades for the Altitude Wind Tunnel

NASA Image and Video Library

1951-08-21

New wooden fan blades being prepared for installation in the Altitude Wind Tunnel at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The facility underwent a major upgrade in 1951 to increase its operating capacities in order to handle the new, more powerful turbojet engines being manufactured in the 1950s. The fan blades were prepared in the shop area, seen in this photograph, before being lowered through a hole in the tunnel and attached to the drive shaft. A new drive bearing and tail faring were also installed on the fan as part of this rehab project. A 12-bladed 31-foot-diameter spruce wood fan generated the 300 to 500 mile-per-hour airflow through the tunnel. An 18,000-horsepower General Electric induction motor located in the rear corner of the Exhauster Building drove the fan at 410 revolutions per minute. An extension shaft, sealed in the tunnel’s shell with flexible couplings that allowed for the movement of the shell, connected the motor to the fan. A bronze screen secured to the turning vanes protected the fan against damage from any engine parts sailing through the tunnel. Despite this screen the blades did become worn or cracked over time and had to be replaced.

Application of higher harmonic blade feathering on the OH-6A helicopter for vibration reduction

NASA Technical Reports Server (NTRS)

Straub, F. K.; Byrns, E. V., Jr.

1986-01-01

The design, implementation, and flight test results of higher harmonic blade feathering for vibration reduction on the OH-6A helicopter are described. The higher harmonic control (HHC) system superimposes fourth harmonic inputs upon the stationary swashplate. These inputs are transformed into 3P, 4P and 5P blade feathering angles. This results in modified blade loads and reduced fuselage vibrations. The primary elements of this adaptive vibration suppression system are: (1) acceleration transducers sensing the vibratory response of the fuselage; (2) a higher harmonic blade pitch actuator system; (3) a flightworthy microcomputer, incorporating the algorithm for reducing vibrations, and (4) a signal conditioning system, interfacing between the sensors, the microcomputer and the HHC actuators. The program consisted of three distinct phases. First, the HHC system was designed and implemented on the MDHC OH-6A helicopter. Then, the open loop, or manual controlled, flight tests were performed, and finally, the closed loop adaptive control system was tested. In 1983, one portion of the closed loop testing was performed, and in 1984, additional closed loop tests were conducted with improved software. With the HHC system engaged, the 4P pilot seat vibration levels were significantly lower than the baseline ON-6A levels. Moreover, the system did not adversely affect blade loads or helicopter performance. In conclusion, this successful proof of concept project demonstrated HHC to be a viable vibration suppression mechanism.

Coping in the Cyberworld: Program Implementation and Evaluation--A Pilot Project

ERIC Educational Resources Information Center

Lam, Cecilia Wing Chi; Frydenberg, Erica

2009-01-01

As increasing numbers of adolescents become involved in online activities, many also become victims of cyberharassment. This pilot project investigates how a program teaching coping skills (Best of Coping program, BOC) and a program teaching cybersafety (Cyber Savvy Teens program, CST) can optimise adolescents' capacity to cope online.…

Analysis and Evaluation of Processes and Equipment in Tasks 2 and 4 of the Low-cost Solar Array Project

NASA Technical Reports Server (NTRS)

Goldman, H.; Wolf, M.

1978-01-01

The significant economic data for the current production multiblade wafering and inner diameter slicing processes were tabulated and compared to data on the experimental and projected multiblade slurry, STC ID diamond coated blade, multiwire slurry and crystal systems fixed abrasive multiwire slicing methods. Cost calculations were performed for current production processes and for 1982 and 1986 projected wafering techniques.

Development of a high-performance transtibial cycling-specific prosthesis for the London 2012 Paralympic Games.

PubMed

Dyer, Bryce; Woolley, Howard

2017-10-01

It has been reported that cycling-specific research relating to participants with an amputation is extremely limited in both volume and frequency. However, practitioners might participate in the development of cycling-specific prosthetic limbs. This technical note presents the development of a successful design of a prosthetic limb developed specifically for competitive cycling. This project resulted in a hollow composite construction which was low in weight and shaped to reduce a rider's aerodynamic drag. The new prosthesis reduces the overall mass of more traditional designs by a significant amount yet provides a more aerodynamic shape over traditional approaches. These decisions have yielded a measurable increase in cycling performance. While further refinement is needed to reduce the aerodynamic drag as much as possible, this project highlights the benefits that can exist by optimising the design of sports-specific prosthetic limbs. Clinical relevance This project resulted in the creation of a cycling-specific prosthesis which was tailored to the needs of a high-performance environment. Whilst further optimisation is possible, this project provides insight into the development of sports-specific prostheses.

Blade Vibration Measurement System

NASA Technical Reports Server (NTRS)

Platt, Michael J.

2014-01-01

The Phase I project successfully demonstrated that an advanced noncontacting stress measurement system (NSMS) could improve classification of blade vibration response in terms of mistuning and closely spaced modes. The Phase II work confirmed the microwave sensor design process, modified the sensor so it is compatible as an upgrade to existing NSMS, and improved and finalized the NSMS software. The result will be stand-alone radar/tip timing radar signal conditioning for current conventional NSMS users (as an upgrade) and new users. The hybrid system will use frequency data and relative mode vibration levels from the radar sensor to provide substantially superior capabilities over current blade-vibration measurement technology. This frequency data, coupled with a reduced number of tip timing probes, will result in a system capable of detecting complex blade vibrations that would confound traditional NSMS systems. The hardware and software package was validated on a compressor rig at Mechanical Solutions, Inc. (MSI). Finally, the hybrid radar/tip timing NSMS software package and associated sensor hardware will be installed for use in the NASA Glenn spin pit test facility.

A comprehensive PIV measurement campaign on a fully equipped helicopter model

NASA Astrophysics Data System (ADS)

De Gregorio, Fabrizio; Pengel, Kurt; Kindler, Kolja

2012-07-01

The flow field around a helicopter is characterised by its inherent complexity including effects of fluid-structure interference, shock-boundary layer interaction, and dynamic stall. Since the advancement of computational fluid dynamics and computing capabilities has led to an increasing demand for experimental validation data, a comprehensive wind tunnel test campaign of a fully equipped and motorised generic medium transport helicopter was conducted in the framework of the GOAHEAD project. Different model configurations (with or without main/tail rotor blades) and several flight conditions were investigated. In this paper, the results of the three-component velocity field measurements around the model are surveyed. The effect of the interaction between the main rotor wake and the fuselage for cruise/tail shake flight conditions was analysed based on the flow characteristics downstream from the rotor hub and the rear fuselage hatch. The results indicated a sensible increment of the intensity of the vortex shedding from the lower part of the fuselage and a strong interaction between the blade vortex filaments and the wakes shed by the rotor hub and by the engine exhaust areas. The pitch-up phenomenon was addressed, detecting the blade tip vortices impacting on the horizontal tail plane. For high-speed forward flight, the shock wave formation on the advancing blade was detected, measuring the location on the blade chord and the intensity. Furthermore, dynamic stall on the retreating main rotor blade in high-speed forward flight was observed at r/ R = 0.5 and 0.6. The analysis of the substructures forming the dynamic stall vortex revealed an unexpected spatial concentration suggesting a rotational stabilisation of large-scale structures on the blade.

An Advanced Actuator Line Method for Wind Energy Applications and Beyond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Churchfield, Matthew J.; Schreck, Scott; Martinez-Tossas, Luis A.

The actuator line method to represent rotor aerodynamics within computational fluid dynamics has been in use for over a decade. This method applies a body force to the flow field along rotating lines corresponding to the individual rotor blades and employs tabular airfoil data to compute the force distribution. The actuator line method is attractive because compared to blade-resolved simulations, the required mesh is much simpler and the computational cost is lower. This work proposes a higher fidelity variant of the actuator line method meant to fill the space between current actuator line and blade-resolved simulations. It contains modifications inmore » two key areas. The first is that of freestream velocity vector estimation along the line, which is necessary to compute the lift and drag along the line using tabular airfoil data. Most current methods rely on point sampling in which the location of sampling is ambiguous. Here we test a velocity sampling method that uses a properly weighted integral over space, removing this ambiguity. The second area of improvement is the function used to project the one-dimensional actuator line force onto the three-dimensional fluid mesh as a body force. We propose and test a projection function that spreads the force over a region that looks something like a real blade with the hope that it will produce the blade local and near wake flow features with more accuracy and higher fidelity. Our goal is that between these two improvements, not only will the flow field predictions be enhanced, but also the spanwise loading will be made more accurate. We refer to this combination of improvements as the advanced actuator line method. We apply these improvements to two different wind turbine cases. Although there is a strong wind energy motivation in our work, there is no reason these advanced actuator line ideas cannot be used in other applications, such as helicopter rotors.« less

An Advanced Actuator Line Method for Wind Energy Applications and Beyond: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Churchfield, Matthew; Schreck, Scott; Martinez-Tossas, Luis A.

The actuator line method to represent rotor aerodynamics within computational fluid dynamics has been in use for over a decade. This method applies a body force to the flow field along rotating lines corresponding to the individual rotor blades and employs tabular airfoil data to compute the force distribution. The actuator line method is attractive because compared to blade-resolved simulations, the required mesh is much simpler and the computational cost is lower. This work proposes a higher fidelity variant of the actuator line method meant to fill the space between current actuator line and blade-resolved simulations. It contains modifications inmore » two key areas. The first is that of freestream velocity vector estimation along the line, which is necessary to compute the lift and drag along the line using tabular airfoil data. Most current methods rely on point sampling in which the location of sampling is ambiguous. Here we test a velocity sampling method that uses a properly weighted integral over space, removing this ambiguity. The second area of improvement is the function used to project the one-dimensional actuator line force onto the three-dimensional fluid mesh as a body force. We propose and test a projection function that spreads the force over a region that looks something like a real blade with the hope that it will produce the blade local and near wake flow features with more accuracy and higher fidelity. Our goal is that between these two improvements, not only will the flow field predictions be enhanced, but also the spanwise loading will be made more accurate. We refer to this combination of improvements as the advanced actuator line method. We apply these improvements to two different wind turbine cases. Although there is a strong wind energy motivation in our work, there is no reason these advanced actuator line ideas cannot be used in other applications, such as helicopter rotors.« less

Blade System Design Study. Part II, final project report (GEC).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffin, Dayton A.

2009-05-01

As part of the U.S. Department of Energy's Low Wind Speed Turbine program, Global Energy Concepts LLC (GEC)1 has studied alternative composite materials for wind turbine blades in the multi-megawatt size range. This work in one of the Blade System Design Studies (BSDS) funded through Sandia National Laboratories. The BSDS program was conducted in two phases. In the Part I BSDS, GEC assessed candidate innovations in composite materials, manufacturing processes, and structural configurations. GEC also made recommendations for testing composite coupons, details, assemblies, and blade substructures to be carried out in the Part II study (BSDS-II). The BSDS-II contract periodmore » began in May 2003, and testing was initiated in June 2004. The current report summarizes the results from the BSDS-II test program. Composite materials evaluated include carbon fiber in both pre-impregnated and vacuum-assisted resin transfer molding (VARTM) forms. Initial thin-coupon static testing included a wide range of parameters, including variation in manufacturer, fiber tow size, fabric architecture, and resin type. A smaller set of these materials and process types was also evaluated in thin-coupon fatigue testing, and in ply-drop and ply-transition panels. The majority of materials used epoxy resin, with vinyl ester (VE) resin also used for selected cases. Late in the project, testing of unidirectional fiberglass was added to provide an updated baseline against which to evaluate the carbon material performance. Numerous unidirectional carbon fabrics were considered for evaluation with VARTM infusion. All but one fabric style considered suffered either from poor infusibility or waviness of fibers combined with poor compaction. The exception was a triaxial carbon-fiberglass fabric produced by SAERTEX. This fabric became the primary choice for infused articles throughout the test program. The generally positive results obtained in this program for the SAERTEX material have led to its being used in innovative prototype blades of 9-m and 30-m length, as well as other non-wind related structures.« less

75 FR 56093 - FFP Mass 1, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13828-000] FFP Mass 1, LLC... study the feasibility of the Cape Cod Tidal Energy Project to be located in the Cape Cod Canal and a...,000 hydrokinetic tidal devices consisting of a turbine blade assembly and an integrated 10-kilowatt...

78 FR 7752 - Trade Mission to Egypt and Kuwait

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-04

..., steam turbines, hydro and wind turbines, blades, and other equipment, as well as development and project... capital of Egypt and the largest city in Africa. The business week runs from Sunday through Thursday...

76 FR 22719 - Cape Wind Energy Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-22

... with a maximum blade height of 440 feet (ft), to be constructed in a grid pattern on the OCS in.... The proposed submarine transmission cable system (115 kilovolt) running from the ESP to the landfall...

Moving towards Optimising Demand-Led Learning: The 2005-2007 ECUANET Leonardo Da Vinci Project

ERIC Educational Resources Information Center

Dealtry, Richard; Howard, Keith

2008-01-01

Purpose: The purpose of this paper is to present the key project learning points and outcomes as a guideline for the future quality management of demand-led learning and development. Design/methodology/approach: The research methodology was based upon a corporate university blueprint architecture and browser toolkit developed by a member of the…

Experimental quiet engine program

NASA Technical Reports Server (NTRS)

Cornell, W. G.

1975-01-01

Full-scale low-tip-speed fans, a full-scale high-tip-speed fan, scale model versions of fans, and two full-scale high-bypass-ratio turbofan engines, were designed, fabricated, tested, and evaluated. Turbine noise suppression was investigated. Preliminary design studies of flight propulsion system concepts were used in application studies to determine acoustic-economic tradeoffs. Salient results are as follows: tradeoff evaluation of fan tip speed and blade loading; systematic data on source noise characteristics and suppression effectiveness; documentation of high- and low-fan-speed aerodynamic and acoustic technology; aerodynamic and acoustic evaluation of acoustic treatment configurations, casing tip bleed, serrated and variable pitch rotor blades, leaned outlet guide vanes, slotted tip casings, rotor blade shape modifications, and inlet noise suppression; systematic evaluation of aerodynamic and acoustic effects; flyover noise projections of engine test data; turbine noise suppression technology development; and tradeoff evaluation of preliminary design high-fan-speed and low-fan-speed flight engines.

Design and use of multiple blade slurry sawing in a production atmosphere

NASA Technical Reports Server (NTRS)

Lynah, F. P., Jr.; Ross, J. B.

1982-01-01

The technique and uses of the multiple blade slurry (MBS) saw are considered. Multiple bands of steel are arranged in a frame and the frame is reciprocated with the steel bands to a workpiece, while simultaneously applying abrasive at the point of contact. The blades wear slots in the workpiece and progress through the piece resulting in several parts of wafers. The transition to MBA from diamond slicing is justified by savings resulting from minimized kerf losses, minimized subsurface damage, and improved surface quality off the saw. This allows wafering much closer to finished thickness specifications. The current state of the art MBS technology must be significantly improved if the low cost solar array (LSA) goals are to be attained. It is concluded that although MBS will never be the answer to every wafering requirement, the economical production of wafers to LSA project specifications will be achieved.

Calibrated Blade-Element/Momentum Theory Aerodynamic Model of the MARIN Stock Wind Turbine: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goupee, A.; Kimball, R.; de Ridder, E. J.

2015-04-02

In this paper, a calibrated blade-element/momentum theory aerodynamic model of the MARIN stock wind turbine is developed and documented. The model is created using open-source software and calibrated to closely emulate experimental data obtained by the DeepCwind Consortium using a genetic algorithm optimization routine. The provided model will be useful for those interested in validating interested in validating floating wind turbine numerical simulators that rely on experiments utilizing the MARIN stock wind turbine—for example, the International Energy Agency Wind Task 30’s Offshore Code Comparison Collaboration Continued, with Correlation project.

Appraisal of ALM predictions of turbulent wake features

NASA Astrophysics Data System (ADS)

Rocchio, Benedetto; Cilurzo, Lorenzo; Ciri, Umberto; Salvetti, Maria Vittoria; Leonardi, Stefano

2017-11-01

Wind turbine blades create a turbulent wake that may persist far downstream, with significant implications on wind farm design and on its power production. The numerical representation of the real blade geometry would lead to simulations beyond the present computational resources. We focus our attention on the Actuator Line Model (ALM), in which the blade is replaced by a rotating line divided into finite segments with representative aerodynamic coefficients. The total aerodynamic force is projected along the computational axis and, to avoid numerical instabilities, it is distributed among the nearest grid points by using a Gaussian regularization kernel. The standard deviation of this kernel is a fundamental parameter that strongly affects the characteristics of the wake. We compare here the wake features obtained in direct numerical simulations of the flow around 2D bodies (a flat plate and an airfoil) modeled using the Immersed Boundary Method with the results of simulations in which the body is modeled by ALM. In particular, we investigate whether the ALM is able to reproduce the mean velocity field and the turbulent kinetic energy in the wake for the considered bodies at low and high angles of attack and how this depends on the choice of the ALM kernel. S. Leonardi was supported by the National Science Foundation, Grant No. 1243482 (the WINDINSPIRE project).

Optimisation and establishment of diagnostic reference levels in paediatric plain radiography

NASA Astrophysics Data System (ADS)

Paulo, Graciano do Nascimento Nobre

Purpose: This study aimed to propose Diagnostic Reference Levels (DRLs) in paediatric plain radiography and to optimise the most frequent paediatric plain radiography examinations in Portugal following an analysis and evaluation of current practice. Methods and materials: Anthropometric data (weight, patient height and thickness of the irradiated anatomy) was collected from 9,935 patients referred for a radiography procedure to one of the three dedicated paediatric hospitals in Portugal. National DRLs were calculated for the three most frequent X-ray procedures at the three hospitals: chest AP/PA projection; abdomen AP projection; pelvis AP projection. Exposure factors and patient dose were collected prospectively at the clinical sites. In order to analyse the relationship between exposure factors, the use of technical features and dose, experimental tests were made using two anthropomorphic phantoms: a) CIRSTM ATOM model 705; height: 110cm, weight: 19kg and b) Kyoto kagakuTM model PBU-60; height: 165cm, weight: 50kg. After phantom data collection, an objective image analysis was performed by analysing the variation of the mean value of the standard deviation, measured with OsiriX software (Pixmeo, Switzerland). After proposing new exposure criteria, a Visual Grading Characteristic image quality evaluation was performed blindly by four paediatric radiologists, each with a minimum of 10 years of professional experience, using anatomical criteria scoring. Results: DRLs by patient weight groups have been established for the first time. ESAKP75 DRLs for both patient age and weight groups were also obtained and are described in the thesis. Significant dose reduction was achieved through the implementation of an optimisation programme: an average reduction of 41% and 18% on KAPP75 and ESAKP75, respectively for chest plain radiography; an average reduction of 58% and 53% on KAPP75 and ESAKP75, respectively for abdomen plain radiography; and an average reduction of 47% and 48% on KAPP75 and ESAKP75, respectively for pelvis plain radiography. Conclusion: Portuguese DRLs for plain radiography were obtained for paediatric plain radiography (chest AP/PA, abdomen and pelvis). Experimental phantom tests identified adequate plain radiography exposure criteria, validated by objective and subjective image quality analysis. The new exposure criteria were put into practice in one of the paediatric hospitals, by introducing an optimisation programme. The implementation of the optimisation programme allowed a significant dose reduction to paediatric patients, without compromising image quality. (Abstract shortened by ProQuest.).

Instrumentation for Performance, Blade Loads and Flowfield Measurement of Novel Hover-Capable Meso-Scale Aerial Platforms

DTIC Science & Technology

2016-12-07

many DoD sponsored MAV projects including one task from ARO and another one as part of Army/Navy/ NASA - sponsored VLRCOE at Maryland all requiring...has undertaken many DoD sponsored MAV projects including one task from ARO and another one as part of Army/Navy/ NASA sponsored Vertical Lift Research

Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade.

PubMed

Ge, Mingwei; Fang, Le; Tian, De

2015-01-01

At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project.

Toward the Active Control of Heat Transfer in the Hot Gas Path of Gas Turbines

NASA Technical Reports Server (NTRS)

Oertling, Jeremiah E.

2003-01-01

The work at NASA this summer has focused on assisting the Professor's project, namely "Toward the Active Control of Heat Transfer in the Hot Gas Path of Gas Turbines." The mode of controlling the Heat Transfer that the project focuses on is film cooling. Film cooling is used in high temperature regions of a gas turbine and extends the life of the components exposed to these extreme temperatures. A "cool" jet of air is injected along the surface of the blade and this layer of cool air shields the blade from the high temperatures. Cool is a relative term. The hot gas path temperatures reach on the order of 1500 to 2000 K. The "coo" air is on the order of 700 to 1000 K. This cooler air is bled off of an appropriate compressor stage. The next parameter of interest is the jet s position and orientation in the flow-field.

Extended Burnup Credit for BWR Spent Nuclear Fuel in Storage and Transportation Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ade, Brian J; Bowman, Stephen M; Gauld, Ian C

2015-01-01

[Full Text] Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling-water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase investigates the applicability of peak reactivity methods currently used for spent fuel pools to spent fuel storage and transportation casks and the validation of reactivity (k eff) calculations and depleted fuel compositions. The second phase focuses on extending BUC beyond peak reactivity. This paper documents work performed to date, investigating some aspects of extended BUC, andmore » it also describes the plan to complete the evaluations. The technical basis for application of peak reactivity methods to BWR fuel in storage and transportation systems is presented in a companion paper. Two reactor operating parameters are being evaluated to establish an adequate basis for extended BWR BUC, including investigation of the axial void profile effect and the effect of control blade utilization during operation. A detailed analysis of core simulator data for one cycle of an operating BWR plant was performed to determine the range of void profiles and the variability of the profile experienced during irradiation. While a single cycle does not provide complete data, the data obtained are sufficient to use to determine the primary effects and identify conservative modeling approaches. Using data resulting from a single cycle, the axial void profile is studied by first determining the temporal fidelity necessary in depletion modeling, and then using multiple void profiles to examine the effect of the void profile on cask reactivity. The results of these studies are being used to develop recommendations for conservatively modeling the void profile effects for BWR depletion calculations. The second operational parameter studied is control blade exposure. Control blades are inserted in various locations and at varying degrees during BWR operation based on the reload design. The presence of control blades during depletion hardens the neutron spectrum locally due to both moderator displacement and introduction of a thermal neutron absorber. The reactivity impact of control blade presence is investigated herein, as well as the effect of multiple (continuous and intermittent) exposure periods. The coupled effects of control blade presence on power density, void profile, or burnup profile have not been considered to date but will be addressed in future work.« less

Design and aerodynamic performance evaluation of a high-work mixed flow turbine stage

NASA Technical Reports Server (NTRS)

Neri, Remo N.; Elliott, Thomas J.; Marsh, David N.; Civinskas, Kestutis C.

1994-01-01

As axial and radial turbine designs have been pushed to their aerothermodynamic and mechanical limits, the mixed-flow turbine (MFT) concept has been projected to offer performance and durability improvements, especially when ceramic materials are considered. The objective of this NASA/U.S. Army sponsored mixed-flow turbine (AMFT) program was to determine the level of performance attainable with MFT technology within the mechanical constraints of 1997 projected ceramic material properties. The MFT geometry is similar to a radial turbine, exhibiting a large radius change from inlet to exit, but differing in that the inlet flowpath is not purely radial, nor axial, but mixed; it is the inlet geometry that gives rise to the name 'mixed-flow'. The 'mixed' orientation of the turbine inlet offers several advantages over radial designs by allowing a nonzero inlet blade angle yet maintaining radial-element blades. The oblique inlet not only improves the particle-impact survivability of the design, but improves the aerodynamic performance by reducing the incidence at the blade inlet. The difficulty, however, of using mixed-flow geometry lies in the scarcity of detailed data and documented design experience. This paper reports the design of a MFT stage designed with the intent to maximize aerodynamic performance by optimizing design parameters such as stage reaction, rotor incidence, flowpath shape, blade shape, vane geometry, and airfoil counts using 2-D, 3-D inviscid, and 3-D viscous computational fluid dynamics code. The aerodynamic optimization was accomplished while maintaining mechanical integrity with respect to vibration and stress levels in the rotor. A full-scale cold-flow rig test was performed with metallic hardware fabricated to the specifications of the hot ceramic geometry to evaluate the stage performance.

Tower wake/blade interaction noise of a wind turbine

NASA Astrophysics Data System (ADS)

Nishiwaki, Hideo; Takeda, Katsumi

1987-10-01

A scale model of a 1.5m dia. two-bladed windturbine was used in an anechoic chamber that provided a free-stream velocity of 8m/s. The blades used were a 1.5/8 scale model of a test machine for a local energy utilization project promoted by the Science and Technology Agency. The height of the tower from the ground level was 1.8m. The acoustic measurements were made in a circle of 1.6m downstream from the machine at the height of the windmill centerline. The noise level of the on-axis spectra was about 15dB larger than that of the off-axis. This is a result of the dipole nature of the acoustic impulse. The Wortmann airfoil (FX 77-W series) was employed for the blade profiles and the Reynolds number was 10(5), based on the tip chord length. The experiment revealed that the sound intensity at each harmonic was not proportional to the axial and radial extents of the wake. The elliptic slender configuration was the quietest, while the square configuration was the loudest. From a practical point of view, it is suggested that the circular section is most suitable for the tower leg.

Integrating Farm Production and Natural Resource Management in Tasmania, Australia

ERIC Educational Resources Information Center

Cotching, W. E.; Sherriff, L.; Kilpatrick, S.

2009-01-01

This paper reports on the social learning from a project aimed to increase the knowledge and capacity of a group of farmers in Tasmania, Australia, to reduce the impacts of intensive agriculture on soil health and waterways, and to optimise the efficient use of on-farm inputs. The plan-do-check-review cycle adopted in this project required the…

Automatic optimisation of gamma dose rate sensor networks: The DETECT Optimisation Tool

NASA Astrophysics Data System (ADS)

Helle, K. B.; Müller, T. O.; Astrup, P.; Dyve, J. E.

2014-05-01

Fast delivery of comprehensive information on the radiological situation is essential for decision-making in nuclear emergencies. Most national radiological agencies in Europe employ gamma dose rate sensor networks to monitor radioactive pollution of the atmosphere. Sensor locations were often chosen using regular grids or according to administrative constraints. Nowadays, however, the choice can be based on more realistic risk assessment, as it is possible to simulate potential radioactive plumes. To support sensor planning, we developed the DETECT Optimisation Tool (DOT) within the scope of the EU FP 7 project DETECT. It evaluates the gamma dose rates that a proposed set of sensors might measure in an emergency and uses this information to optimise the sensor locations. The gamma dose rates are taken from a comprehensive library of simulations of atmospheric radioactive plumes from 64 source locations. These simulations cover the whole European Union, so the DOT allows evaluation and optimisation of sensor networks for all EU countries, as well as evaluation of fencing sensors around possible sources. Users can choose from seven cost functions to evaluate the capability of a given monitoring network for early detection of radioactive plumes or for the creation of dose maps. The DOT is implemented as a stand-alone easy-to-use JAVA-based application with a graphical user interface and an R backend. Users can run evaluations and optimisations, and display, store and download the results. The DOT runs on a server and can be accessed via common web browsers; it can also be installed locally.

14 CFR 27.339 - Resultant limit maneuvering loads.

Code of Federal Regulations, 2010 CFR

2010-01-01

... velocity component in the plane of the rotor disc to the rotational tip speed of the rotor blades, and is... the projection, in the plane of symmetry, of the axis of no feathering and a line perpendicular to the...

14 CFR 29.339 - Resultant limit maneuvering loads.

Code of Federal Regulations, 2010 CFR

2010-01-01

... velocity component in the plane of the rotor disc to the rotational tip speed of the rotor blades, and is... the projection, in the plane of symmetry, of the axis of no feathering and a line perpendicular to the...

Establishment of a National Wind Energy Center at University of Houston

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Su Su

The DOE-supported project objectives are to: establish a national wind energy center (NWEC) at University of Houston and conduct research to address critical science and engineering issues for the development of future large MW-scale wind energy production systems, especially offshore wind turbines. The goals of the project are to: (1) establish a sound scientific/technical knowledge base of solutions to critical science and engineering issues for developing future MW-scale large wind energy production systems, (2) develop a state-of-the-art wind rotor blade research facility at the University of Houston, and (3) through multi-disciplinary research, introducing technology innovations on advanced wind-turbine materials, processing/manufacturingmore » technology, design and simulation, testing and reliability assessment methods related to future wind turbine systems for cost-effective production of offshore wind energy. To achieve the goals of the project, the following technical tasks were planned and executed during the period from April 15, 2010 to October 31, 2014 at the University of Houston: (1) Basic research on large offshore wind turbine systems (2) Applied research on innovative wind turbine rotors for large offshore wind energy systems (3) Integration of offshore wind-turbine design, advanced materials and manufacturing technologies (4) Integrity and reliability of large offshore wind turbine blades and scaled model testing (5) Education and training of graduate and undergraduate students and post- doctoral researchers (6) Development of a national offshore wind turbine blade research facility The research program addresses both basic science and engineering of current and future large wind turbine systems, especially offshore wind turbines, for MW-scale power generation. The results of the research advance current understanding of many important scientific issues and provide technical information for solving future large wind turbines with advanced design, composite materials, integrated manufacturing, and structural reliability and integrity. The educational program have trained many graduate and undergraduate students and post-doctoral level researchers to learn critical science and engineering of wind energy production systems through graduate-level courses and research, and participating in various projects in center’s large multi-disciplinary research. These students and researchers are now employed by the wind industry, national labs and universities to support the US and international wind energy industry. The national offshore wind turbine blade research facility developed in the project has been used to support the technical and training tasks planned in the program to accomplish their goals, and it is a national asset which is available for used by domestic and international researchers in the wind energy arena.« less

Dynamic least-cost optimisation of wastewater system remedial works requirements.

PubMed

Vojinovic, Z; Solomatine, D; Price, R K

2006-01-01

In recent years, there has been increasing concern for wastewater system failure and identification of optimal set of remedial works requirements. So far, several methodologies have been developed and applied in asset management activities by various water companies worldwide, but often with limited success. In order to fill the gap, there are several research projects that have been undertaken in exploring various algorithms to optimise remedial works requirements, but mostly for drinking water supply systems, and very limited work has been carried out for the wastewater assets. Some of the major deficiencies of commonly used methods can be found in either one or more of the following aspects: inadequate representation of systems complexity, incorporation of a dynamic model into the decision-making loop, the choice of an appropriate optimisation technique and experience in applying that technique. This paper is oriented towards resolving these issues and discusses a new approach for the optimisation of wastewater systems remedial works requirements. It is proposed that the optimal problem search is performed by a global optimisation tool (with various random search algorithms) and the system performance is simulated by the hydrodynamic pipe network model. The work on assembling all required elements and the development of an appropriate interface protocols between the two tools, aimed to decode the potential remedial solutions into the pipe network model and to calculate the corresponding scenario costs, is currently underway.

Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

NASA Astrophysics Data System (ADS)

Žandeckis, A.; Timma, L.; Blumberga, D.; Rochas, C.; Rošā, M.

2012-01-01

The paper focuses on the application of wood pellet and solar combisystem for space heating and hot water preparation at apartment buildings under the climate of Northern Europe. A pilot project has been implemented in the city of Sigulda (N 57° 09.410 E 024° 52.194), Latvia. The system was designed and optimised using TRNSYS - a dynamic simulation tool. The pilot project was continuously monitored. To the analysis the heat transfer fluid flow rate and the influence of the inlet temperature on the performance of solar collectors were subjected. The thermal performance of a solar collector loop was studied using a direct method. A multiple regression analysis was carried out using STATGRAPHICS Centurion 16.1.15 with the aim to identify the operational and weather parameters of the system which cause the strongest influence on the collector's performance. The parameters to be used for the system's optimisation have been evaluated.

Creating Pathways to Success for Supersized Wind Turbine Blades: 2018 Workshop Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffin, Dayton

A workshop on Pathways to Success for Supersized Wind Turbine Blades was conducted by the U.S. Department of Energy’s (DOE’s) office of Energy Efficiency and Renewable Energy (EERE) at the Kimpton Hotel Palomar in Washington D.C., on March 6-7, 2018. Approximately 40-50 experts and industry stakeholders came together for the event, including manufacturers, transportation specialists, project developers, operators, engineering firms, consultants, and university researchers. Technical experts from the national laboratories and WETO were also present to engage in discussions about solving the challenges faced by supersized wind turbine blades. The workshop attendees participated in evaluating the current status of windmore » turbine blade design, manufacture, transportation, erection and operation, identifying constraints to cost-effective application of current technologies and methods for blades of increasing size, and discussing needs and opportunities for research, development and deployment of materials, manufacturing, structural configuration, and transportation. The workshop was one step within a larger initiative to identify specific R&D opportunities DOE could pursue to address technical barriers or implementation challenges faced by the U.S. wind energy industry to achieve continued decreases in LCOE. Following a plenary session, the 2-day workshop featured three group discussion sessions, with each session focusing on a specific “pathway” to enabling LCOE reductions for rotor blades of increasing size. The three pathways considered were “on-site manufacture,” “transport,” and “hybrid and alternative,” which included various options involving central manufacturing of sub-elements following on-site assembly. Each of the pathway group discussions was opened with a short presentation from one or more invited speakers, followed by an open discussion with balanced input from stakeholder groups and individuals. Participation among the workshop attendees was considered highly productive. Experts and stakeholders were engaged throughout the sessions and offered significant insights into the challenges and potential enabling technologies for supersized blades. Discussion highlights and take-aways for the three pathways are described.« less

Manufacturing Methods & Technology (MMT) Project Execution Report

DTIC Science & Technology

1982-10-01

managers. This document is used as a management tool for monitoring the progress of MMT projects. There are separate sections in the report showing...in this area will insure a use- ful review of the progression of the MMT Program. Relative to the second are of concern, there has always been a...THRU 5. DAMAGE TU ANY UNE BLADE DURING MANUFACTURING CR IN THE FIELD RESULTS IN SCRAPPING THE WHOLE BLISK. 25 I II I_ _IL PROJECTS ADWI IN 1ST HALF

Inlet Turbulence and Length Scale Measurements in a Large Scale Transonic Turbine Cascade

NASA Technical Reports Server (NTRS)

Thurman, Douglas; Flegel, Ashlie; Giel, Paul

2014-01-01

Constant temperature hotwire anemometry data were acquired to determine the inlet turbulence conditions of a transonic turbine blade linear cascade. Flow conditions and angles were investigated that corresponded to the take-off and cruise conditions of the Variable Speed Power Turbine (VSPT) project and to an Energy Efficient Engine (EEE) scaled rotor blade tip section. Mean and turbulent flowfield measurements including intensity, length scale, turbulence decay, and power spectra were determined for high and low turbulence intensity flows at various Reynolds numbers and spanwise locations. The experimental data will be useful for establishing the inlet boundary conditions needed to validate turbulence models in CFD codes.

75 FR 23798 - Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... calls for 130, 3.6 megawatt (MW) wind turbine generators, each with a maximum blade height of 440 feet... transmission cables, which would run through Massachusetts' territory to shore. For reference, the northernmost...

75 FR 10500 - Environmental Assessment Prepared for Proposed Cape Wind Energy Project in Nantucket Sound, MA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... calls for 130, 3.6 megawatt (MW) wind turbine generators, each with a maximum blade height of 440 feet... in Federal waters, aside from transmission cables running through Massachusetts waters ashore. For...

Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade

PubMed Central

Ge, Mingwei; Fang, Le; Tian, De

2015-01-01

At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (C Popt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger C Popt or AEP (C Popt//AEP) for the same ultimate load, or a smaller load for the same C Popt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum C popt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and C popt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project. PMID:26528815

Conceptualising Changes to Pre-Service Teachers' Knowledge of How to Best Facilitate Learning in Mathematics: A TPACK Inspired Initiative

ERIC Educational Resources Information Center

Bate, Frank G.; Day, Lorraine; Macnish, Jean

2013-01-01

In 2010, the Australian Commonwealth government initiated an $8m project called Teaching Teachers for the Future. The aim of the project was to engage teacher educators in a professional learning network which focused on optimising exemplary use of information and communications technologies in teacher education. By taking part in this network,…

Jet Engine Fan Response to Inlet Distortions Generated by Ingesting Boundary Layer Flow

NASA Astrophysics Data System (ADS)

Giuliani, James Edward

Future civil transport designs may incorporate engines integrated into the body of the aircraft to take advantage of efficiency increases due to weight and drag reduction. Additional increases in engine efficiency are predicted if the inlets ingest the lower momentum boundary layer flow that develops along the surface of the aircraft. Previous studies have shown, however, that the efficiency benefits of Boundary Layer Ingesting (BLI) inlets are very sensitive to the magnitude of fan and duct losses, and blade structural response to the non-uniform flow field that results from a BLI inlet has not been studied in-depth. This project represents an effort to extend the modeling capabilities of TURBO, an existing rotating turbomachinery unsteady analysis code, to include the ability to solve the external and internal flow fields of a BLI inlet. The TURBO code has been a successful tool in evaluating fan response to flow distortions for traditional engine/inlet integrations. Extending TURBO to simulate the external and inlet flow field upstream of the fan will allow accurate pressure distortions that result from BLI inlet configurations to be computed and used to analyze fan aerodynamics and structural response. To validate the modifications for the BLI inlet flow field, an experimental NASA project to study flush-mounted S-duct inlets with large amounts of boundary layer ingestion was modeled. Results for the flow upstream and in the inlet are presented and compared to experimental data for several high Reynolds number flows to validate the modifications to the solver. Once the inlet modifications were validated, a hypothetical compressor fan was connected to the inlet, matching the inlet operating conditions so that the effect on the distortion could be evaluated. Although the total pressure distortion upstream of the fan was symmetrical for this geometry, the pressure rise generated by the fan blades was not, because of the velocity non-uniformity of the distortion. Total pressure profiles at various axial locations are computed to identify the overall distortion pattern, how the distortion evolves through the blade passages and mixes out downstream of the blades, and where any critical performance concerns might be. Stall cells are identified that are stationary in the absolute frame and are fixed to the inlet distortion. Flow paths around the blades are examined to study the stall mechanism. Rather than a static airfoil stall, it is observed that the non-uniform pressure loading promotes a three-dimensional dynamic stall. The stall occurs at a point of rapid incidence angle oscillation, observed when a blade passes through the distortion, and re-attaches when the blade leaves the distortion.

On the functional design of the DTU10 MW wind turbine scale model of LIFES50+ project

NASA Astrophysics Data System (ADS)

Bayati, I.; Belloli, M.; Bernini, L.; Fiore, E.; Giberti, H.; Zasso, A.

2016-09-01

This paper illustrates the mechatronic design of the wind tunnel scale model of the DTU 10MW reference wind turbine, for the LIFES50+ H2020 European project. This model was designed with the final goal of controlling the angle of attack of each blade by means of miniaturized servomotors, for implementing advanced individual pitch control (IPC) laws on a Floating Offshore Wind Turbine (FOWT) 1/75 scale model. Many design constraints were to be respected: among others, the rotor-nacelle overall mass due to aero-elastic scaling, the limited space of the nacelle, where to put three miniaturized servomotors and the main shaft one, with their own inverters/controllers, the slip rings for electrical rotary contacts, the highest stiffness as possible for the nacelle support and the blade-rotor connections, for ensuring the proper kinematic constraint, considering the first flapwise blade natural frequency, the performance of the servomotors to guarantee the wide frequency band due to frequency scale factors, etc. The design and technical solutions are herein presented and discussed, along with an overview of the building and verification process. Also a discussion about the goals achieved and constraints respected for the rigid wind turbine scale model (LIFES50+ deliverable D.3.1) and the further possible improvements for the IPC-aero-elastic scale model, which is being finalized at the time of this paper.

Transonic Fan/Compressor Rotor Design Study. Volume 5

DTIC Science & Technology

1982-02-01

Fan Aircraft Engines Compressor Blade Thickness Rotor Camber Distribution Aerodesign Throat Margin Aerodynamics 20. ABStTRACT (Continue n reverse...Technology Branch FOR THE COMNANDER H. IV N BUS Director, Turbine Engine Division A If your address has changed, if you wish to be removed from our...ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK General Electric Ctmpany AREA & WORK UNIT NUMBERS Aircraft Engine Business Group Project 2307

75 FR 53301 - Notice of a Regional Project Waiver of Section 1605 (Buy American) of the American Recovery and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-31

... blades are completely submerged. No stainless steel jackets that cover a cast iron housing shall be... shaft and hub grease chamber from the mixed media, running on a stainless steel exchangeable wear...

Slicing of Silicon into Sheet Material: Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project

NASA Technical Reports Server (NTRS)

Fleming, J. R.

1979-01-01

Testing of low cost low suspension power slurry vehicles is presented. Cutting oils are unlikely to work, but a mineral oil with additives should be workable. Two different abrasives were tested. A cheaper silicon carbide from Norton gave excellent results except for excessive kerf loss: the particles were too big. An abrasive treated for lubricity showed no lubricity improvement in mineral oil vehicle. The bounce fixture was tested for the first time under constant cut rate conditions (rather than constant force). Although the cut was not completed before the blades broke, the blade lifetime of thin (100 micrometer) blades was 120 times the lifetime without the fixture. The large prototype saw completed a successful run, producing 90% cutting yield (849 wafers) at 20 wafers/cm. Although inexperience with large numbers of wafers caused cleaning breakage to reduce this yield to 74%, the yield was high enough that the concept of the large saw is proven workable.

In-flight measurements of propeller blade deformation on a VUT100 cobra aeroplane using a co-rotating camera system

NASA Astrophysics Data System (ADS)

Boden, F.; Stasicki, B.; Szypuła, M.; Ružička, P.; Tvrdik, Z.; Ludwikowski, K.

2016-07-01

Knowledge of propeller or rotor blade behaviour under real operating conditions is crucial for optimizing the performance of a propeller or rotor system. A team of researchers, technicians and engineers from Avia Propeller, DLR, EVEKTOR and HARDsoft developed a rotating stereo camera system dedicated to in-flight blade deformation measurements. The whole system, co-rotating with the propeller at its full speed and hence exposed to high centrifugal forces and strong vibration, had been successfully tested on an EVEKTOR VUT 100 COBRA aeroplane in Kunovice (CZ) within the project AIM2—advanced in-flight measurement techniques funded by the European Commission (contract no. 266107). This paper will describe the work, starting from drawing the first sketch of the system up to performing the successful flight test. Apart from a description of the measurement hardware and the applied IPCT method, the paper will give some impressions of the flight test activities and discuss the results obtained from the measurements.

Slicing of silicon into sheet material: Silicon sheet growth development for the large area silicon sheet task of the Low Cost Silicon Solar Array project

NASA Technical Reports Server (NTRS)

Fleming, J. R.

1978-01-01

The limits of blade tolerance were defined. The standard blades are T-2 thickness tolerance. Good results were obtained by using a slurry fluid consisting of mineral oil and a lubricity additive. Adjustments of the formulation and fine tuning of the cutting process with the new fluid are necessary. Test results and consultation indicate that the blade breakage encountered with water based slurries is unavoidable. Two full capacity (974 wafer) runs were made on the large prototype saw. Both runs resulted in extremely low yield. However, the reasons for the low yield were lack of proper technique rather than problems with machine function. The test on the effect of amount of material etched off of an as-sawn wafer on solar cell efficiency were completed. The results agree with previous work at JPL in that the minimum material removed per side that gives maximum efficiency is on the order of 10 microns.

Latin American dose survey results in mammography studies under IAEA programme: radiological protection of patients in medical exposures (TSA3).

PubMed

Mora, Patricia; Blanco, Susana; Khoury, Helen; Leyton, Fernando; Cárdenas, Juan; Defaz, María Yolanda; Garay, Fernando; Telón, Flaviano; Aguilar, Juan Garcia; Roas, Norma; Gamarra, Mirtha; Blanco, Daniel; Quintero, Ana Rosa; Nader, Alejandro

2015-03-01

Latin American countries (Argentina, Brazil, Chile, Costa Rica, Cuba, Ecuador, El Salvador, Guatemala, Mexico, Nicaragua, Paraguay, Uruguay and Venezuela) working under the International Atomic Energy Agency (IAEA) Technical Cooperation Programme: TSA3 Radiological Protection of Patients in Medical Exposures have joined efforts in the optimisation of radiation protection in mammography practice. Through surveys of patient doses, the region has a unique database of diagnostic reference levels for analogue and digital equipment that will direct future optimisation activities towards the early detection of breast cancer among asymptomatic women. During RLA9/057 (2007-09) 24 institutions participated with analogue equipment in a dose survey. Regional training on methodology and measurement equipment was addressed in May 2007. The mean glandular dose (DG) was estimated using the incident kerma in air and relevant conversion coefficients for both projections craneo caudal and mediolateral oblique (CC and MLO). For Phase 2, RLA9/067 (2010-11), it was decided to include also digital systems in order to see their impact in future dose optimisation activities. Any new country that joined the project received training in the activities through IAEA expert missions. Twenty-nine new institutions participated (9 analogue and 20 digital equipment). A total of 2262 patient doses were collected during this study and from them D(G) (mGy) for both projections were estimated for each institution and country. Regional results (75 percentile in mGy) show for CC and MLO views, respectively: RLA9/057 (analogue) 2.63 and 3.17; RLA/067: 2.57 and 3.15 (analogue) and 2.69 and 2.90 (digital). Regarding only digital equipment for CC and MLO, respectively, computed radiography systems showed 2.59 and 2.78 and direct digital radiography (DDR) systems 2.78 and 3.04. Based on the IAEA Basic Safety Standard (BSS) reference dose (3 mGy), it can be observed that there is enough room to start optimisation processes in Latin America (LA); several countries or even particular institutions have values much higher than the 3 mGy. The main issues to address are lack of well-established quality assurance programmes for mammography, not enough medical physicists with training in mammography, an increase in patient doses with the introduction of digital equipment and to create awareness on radiation risk and optimisation strategies. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Turbine Engine Hot Section Technology, 1985

NASA Technical Reports Server (NTRS)

1985-01-01

The Turbine Engine Section Technology (HOST) Project Office of the Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine hot section durability problems. Presentations were made concerning hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes.

Preliminary measurement of the noise from the 2/9 scale model of the Large-scale Advanced Propfan (LAP) propeller, SR-7A

NASA Technical Reports Server (NTRS)

Dittmar, J. H.

1985-01-01

Noise data on the Large-scale Advanced Propfan (LAP) propeller model SR-7A were taken into the NASA Lewis 8- by 6-Foot Wind Tunnel. The maximum blade passing tone decreases from the peak level when going to higher helical tip Mach numbers. This noise reduction points to the use of higher propeller speeds as a possible method to reduce airplane cabin noise while maintaining high flight speed and efficiency. Comparison of the SR-7A blade passing noise with the noise of the similarly designed SR-3 propeller shows good agreement as expected. The SR-7A propeller is slightly noisier than the SR-3 model in the plane of rotation at the cruise condition. Projections of the tunnel model data are made to the full-scale LAP propeller mounted on the test bed aircraft and compared with design predictions. The prediction method is conservative in the sense that it overpredicts the projected model data.

Improving Engine Efficiency Through Core Developments

NASA Technical Reports Server (NTRS)

Heidmann, James D.

2011-01-01

The NASA Environmentally Responsible Aviation (ERA) Project and Fundamental Aeronautics Projects are supporting compressor and turbine research with the goal of reducing aircraft engine fuel burn and greenhouse gas emissions. The primary goals of this work are to increase aircraft propulsion system fuel efficiency for a given mission by increasing the overall pressure ratio (OPR) of the engine while maintaining or improving aerodynamic efficiency of these components. An additional area of work involves reducing the amount of cooling air required to cool the turbine blades while increasing the turbine inlet temperature. This is complicated by the fact that the cooling air is becoming hotter due to the increases in OPR. Various methods are being investigated to achieve these goals, ranging from improved compressor three-dimensional blade designs to improved turbine cooling hole shapes and methods. Finally, a complementary effort in improving the accuracy, range, and speed of computational fluid mechanics (CFD) methods is proceeding to better capture the physical mechanisms underlying all these problems, for the purpose of improving understanding and future designs.

Bulb turbine operating at medium head: XIA JIANG case study

NASA Astrophysics Data System (ADS)

Loiseau, F.; Desrats, C.; Petit, P.; Liu, J.

2012-11-01

With lots of references for 4-blade bulb turbines, such as these of Wu Jin Xia (4 units - 36.1 MW per unit - 9.2 m rated head), Chang Zhou (15 units - 46.7 MW per unit - 9.5 m rated head) and Tong Wan (4 units - 46.2 MW per unit - 11 m rated head), ALSTOM Power Hydro is one of the major suppliers of bulb turbines operating under medium head for the Chinese market. ALSTOM Power Hydro has been awarded in November 2010 a contract by Jiang Xi Province Xia Jiang Water Control Project Headquarters to equip Xia Jiang's new hydropower plant. The power dam is located on the Gan Jiang river, at about 160 km away from Nan Chang town in South Eastern China. The supply will consist in 5 bulb units including the furniture of both the turbine and its generator, for a total capacity of 200 MW, under a rated net head of 8.6 m. The prototype turbine is a 7.8 m diameter runner, rotating at 71.4 rpm speed. For this project, ALSTOM has proposed a fully new design of 4-blade bulb runner. This paper outlines the main steps of the hydraulic development. First of all, a fine tuning of the blade geometry was performed to enhance the runner behaviour at high loads and low heads, so that to fulfill the demanding requirements of efficiencies and maximum output. The challenge was also to keep an excellent cavitation behaviour, especially at the outer blade diameter in order to avoid cavitation erosion on the prototype. The shape of the blade was optimized by using the latest tools in computational fluid dynamics. Steady state simulations of the distributor and the runner were performed, in order to simulate more accurately the pressure fields on the blade and the velocity distribution at the outlet of the runner. Moreover, draft tube computations have been performed close to the design point and at higher loads. Then, a model fully homologous with the prototype was manufactured and tested at ALSTOM's laboratory in Grenoble (France). The model test results confirmed the predicted ones: the expected weighted average efficiency is higher than the guaranteed value and the maximum output was reached with a comfortable safety margin. A comparison of the experimental and numerical velocity probings under the runner is also proposed as an insight into the prediction of flow behaviour at the inlet of the draft tube.

Turbine airfoil deposition models and their hot corrosion implications

NASA Technical Reports Server (NTRS)

Rosner, D. E.; Nagarajan, R.

1985-01-01

This research project deals with the prediction of single- and multi-component salt(-solution) deposition, flow and oxide dissolution and their effects on the lifetime of turbine blades. Goals include rationalizing and helping to predict corrosion patterns on operational gas turbine (GT) rotor blades and stator vanes, and ultimately providing some of the tools required to design laboratory simulators and future corrosion resistant high-performance engines. Necessary background developments are reviewed. Results and tentative conclusions for single species (Na sub 2 SO sub 4 (1)) condensation, binary salt-solution (Na sub 2 SO sub 4-K sub 2 SO sub 4) condensation, and burner-rig testing of alloy materials are outlined.

Materials for advanced rocket engine turbopump turbine blades

NASA Technical Reports Server (NTRS)

Chandler, W. T.

1985-01-01

A study program was conducted to identify those materials that will provide the greatest benefits as turbine blades for advanced liquid propellant rocket engine turbines and to prepare technology plans for the development of those materials for use in the 1990 through 1995 period. The candidate materials were selected from six classes of materials: single-crystal (SC) superalloys, oxide dispersion-strengthened (ODS) superalloys, rapid solidification processed (RSP) superalloys, directionally solidified eutectic (DSE) superalloys, fiber-reinforced superalloy (FRS) composites, and ceramics. Properties of materials from the six classes were compiled and evaluated and property improvements were projected approximately 5 years into the future for advanced versions of materials in each of the six classes.

Current Problems in Turbomachinery Fluid Dynamics.

DTIC Science & Technology

1982-05-21

Research Center. It is thought to result from the termination of the 3-D bow shock as the relAtive blade Mach decreases ,.zom tip to hub. This low...project emphasized development of at least a plausible inverse scheme for mixed supersonic, subsonic flow with the possibility of shock waves appearing...Calculation Procedure for Shock -Free or Strong Passage Shock Turbomachinery Cascades," ASME paper 82-GT-220. The next phase of this project was expected to

Thick airfoil designs for the root of the 10MW INNWIND.EU wind turbine

NASA Astrophysics Data System (ADS)

Mu≁oz, A.; Méndez, B.; Munduate, X.

2016-09-01

The main objective of the “INNWIND.EU” project is to investigate and demonstrate innovative designs for 10-20MW offshore wind turbines and their key components, such as lightweight rotors. In this context, the present paper describes the development of two new airfoils for the blade root region. From the structural point of view, the root is the region in charge of transmitting all the loads of the blade to the hub. Thus, it is very important to include airfoils with adequate structural properties in this region. The present article makes use of high-thickness and blunt trailing edge airfoils to improve the structural characteristics of the airfoils used to build this blade region. CENER's (National Renewable Energy Center of Spain) airfoil design tool uses the airfoil software XFOIL to compute the aerodynamic characteristics of the designed airfoils. That software is based on panel methods which show some problems with the calculation of airfoils with thickness bigger than 35% and with blunt trailing edge. This drawback has been overcome with the development of an empirical correction for XFOIL lift and drag prediction based on airfoil experiments. From the aerodynamic point of view, thick airfoils are known to be very sensitive to surface contamination or turbulent inflow conditions. Consequently, the design optimization takes into account the aerodynamic torque in both clean and contaminated conditions. Two airfoils have been designed aiming to improve the structural and the aerodynamic behaviour of the blade in clean and contaminated conditions. This improvement has been corroborated with Blade Element Momentum (BEM) computations.

An engineering approach for the application of textile composites to a structural component

NASA Technical Reports Server (NTRS)

Baldwin, Jack W.; Gracias, Brian K.; Clark, Steven R.

1993-01-01

An engineering approach for the application of textile composites to a structural component is addressed. The main objective is to improve impact resistance of composite blades by using some form of 3-D reinforcement. Project goals, results, and conclusions are discussed.

The faint intergalactic-medium red-shifted emission balloon: future UV observations with EMCCDs

NASA Astrophysics Data System (ADS)

Kyne, Gillian; Hamden, Erika T.; Lingner, Nicole; Morrissey, Patrick; Nikzad, Shouleh; Martin, D. Christopher

2016-08-01

We present the latest developments in our joint NASA/CNES suborbital project. This project is a balloon-borne UV multi-object spectrograph, which has been designed to detect faint emission from the circumgalactic medium (CGM) around low redshift galaxies. One major change from FIREBall-1 has been the use of a delta-doped Electron Multiplying CCD (EMCCD). EMCCDs can be used in photon-counting (PC) mode to achieve extremely low readout noise (¡ 1e-). Our testing initially focused on reducing clock-induced-charge (CIC) through wave shaping and well depth optimisation with the CCD Controller for Counting Photons (CCCP) from Nüvü. This optimisation also includes methods for reducing dark current, via cooling and substrate voltage adjustment. We present result of laboratory noise measurements including dark current. Furthermore, we will briefly present some initial results from our first set of on-sky observations using a delta-doped EMCCD on the 200 inch telescope at Palomar using the Palomar Cosmic Web Imager (PCWI).

The Energy-Efficient Quarry: Towards improved understanding and optimisation of energy use and minimisation of CO2 generation in the aggregates industry.

NASA Astrophysics Data System (ADS)

Hill, Ian; White, Toby; Owen, Sarah

2014-05-01

Extraction and processing of rock materials to produce aggregates is carried out at some 20,000 quarries across the EU. All stages of the processing and transport of hard and dense materials inevitably consume high levels of energy and have consequent significant carbon footprints. The FP7 project "the Energy Efficient Quarry" (EE-Quarry) has been addressing this problem and has devised strategies, supported by modelling software, to assist the quarrying industry to assess and optimise its energy use, and to minimise its carbon footprint. Aggregate quarries across Europe vary enormously in the scale of the quarrying operations, the nature of the worked mineral, and the processing to produce a final market product. Nevertheless most quarries involve most or all of a series of essential stages; deposit assessment, drilling and blasting, loading and hauling, and crushing and screening. The process of determining the energy-efficiency of each stage is complex, but is broadly understood in principle and there are numerous sources of information and guidance available in the literature and on-line. More complex still is the interaction between each of these stages. For example, using a little more energy in blasting to increase fragmentation may save much greater energy in later crushing and screening, but also generate more fines material which is discarded as waste and the embedded energy in this material is lost. Thus the calculation of the embedded energy in the waste material becomes an input to the determination of the blasting strategy. Such feedback loops abound in the overall quarry optimisation. The project has involved research and demonstration operations at a number of quarries distributed across Europe carried out by all partners in the EE-Quarry project, working in collaboration with many of the major quarrying companies operating in the EU. The EE-Quarry project is developing a sophisticated modelling tool, the "EE-Quarry Model" available to the quarrying industry on a web-based platform. This tool guides quarry managers and operators through the complex, multi-layered, iterative, process of assessing the energy efficiency of their own quarry operation. They are able to evaluate the optimisation of the energy-efficiency of the overall quarry through examining both the individual stages of processing, and the interactions between them. The project is also developing on-line distance learning modules designed for Continuous Professional Development (CPD) activities for staff across the quarrying industry in the EU and beyond. The presentation will describe development of the model, and the format and scope of the resulting software tool and its user-support available to the quarrying industry.

SPORE-EXPULSION RATES AND EXTENTS OF BLADE OCCUPATION BY ASCOMYCETES OF THE SMOOTH-CORDGRASS STANDING-DECAY SYSTEM. (R825147)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

77 FR 33439 - Trade Mission to Egypt and Kuwait

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-06

... turbines, steam turbines, wind turbines, blades, and other equipment, as well as development and project... business week runs from Sunday through Thursday. Kuwait City is the capital of Kuwait. The business week runs from Sunday through Thursday. In each city, participants will meet with new business contacts...

75 FR 5070 - TideWorks, LLC; Notice of Application Tendered for Filing With the Commission and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-01

... vertical shaft turbine generating unit with four 4-inch-wide, 5-foot-long blades; (3) a new 3.5-foot-wide... generation of about 22,000 kilowatt-hours. The project would operate in a run-of-river mode using the river...

Present situation and trend of precision guidance technology and its intelligence

NASA Astrophysics Data System (ADS)

Shang, Zhengguo; Liu, Tiandong

2017-11-01

This paper first introduces the basic concepts of precision guidance technology and artificial intelligence technology. Then gives a brief introduction of intelligent precision guidance technology, and with the help of development of intelligent weapon based on deep learning project in foreign: LRASM missile project, TRACE project, and BLADE project, this paper gives an overview of the current foreign precision guidance technology. Finally, the future development trend of intelligent precision guidance technology is summarized, mainly concentrated in the multi objectives, intelligent classification, weak target detection and recognition, intelligent between complex environment intelligent jamming and multi-source, multi missile cooperative fighting and other aspects.

Technological assessment of local manufacturers for wind turbine blade manufacturing in Pakistan

NASA Astrophysics Data System (ADS)

Mahmood, Khurram; Haroon, General

2012-11-01

Composite materials manufacturing industry is one of the world's hi-tech industry. Manufacturing of wind turbine blades is one of the specialized fields requiring high degree of precision and composite manufacturing techniques. This paper identifies the industries specializing in the composite manufacturing and is able to manufacture wind turbines blades in Pakistan. In the second phase, their technology readiness level is determined, based on some factors and then a readiness level are assigned to them. The assigned technology readiness level will depict the absorptive capacity of each manufacturing unit and its capability to take on such projects. The individual readiness level of manufacturing unit will then be used to establish combined technology readiness level of Pakistan particularly for wind turbine blades manufacturing. The composite manufacturing industry provides many spin offs and a diverse range of products can be manufactured using this facility. This research will be helpful to categorize the strong points and flaws of local industry for the gap analysis. It can also be used as a prerequisite study before the evaluation of technologies and specialties to improve the industry of the country for the most favorable results. This will form a basic data base which can be used for the decision making related to transfer of technology, training of local skilled workers and general up-gradation of the local manufacturing units.

Large eddy simulation for predicting turbulent heat transfer in gas turbines

PubMed Central

Tafti, Danesh K.; He, Long; Nagendra, K.

2014-01-01

Blade cooling technology will play a critical role in the next generation of propulsion and power generation gas turbines. Accurate prediction of blade metal temperature can avoid the use of excessive compressed bypass air and allow higher turbine inlet temperature, increasing fuel efficiency and decreasing emissions. Large eddy simulation (LES) has been established to predict heat transfer coefficients with good accuracy under various non-canonical flows, but is still limited to relatively simple geometries and low Reynolds numbers. It is envisioned that the projected increase in computational power combined with a drop in price-to-performance ratio will make system-level simulations using LES in complex blade geometries at engine conditions accessible to the design process in the coming one to two decades. In making this possible, two key challenges are addressed in this paper: working with complex intricate blade geometries and simulating high-Reynolds-number (Re) flows. It is proposed to use the immersed boundary method (IBM) combined with LES wall functions. A ribbed duct at Re=20 000 is simulated using the IBM, and a two-pass ribbed duct is simulated at Re=100 000 with and without rotation (rotation number Ro=0.2) using LES with wall functions. The results validate that the IBM is a viable alternative to body-conforming grids and that LES with wall functions reproduces experimental results at a much lower computational cost. PMID:25024418

Comparison of some optimal control methods for the design of turbine blades

NASA Technical Reports Server (NTRS)

Desilva, B. M. E.; Grant, G. N. C.

1977-01-01

This paper attempts a comparative study of some numerical methods for the optimal control design of turbine blades whose vibration characteristics are approximated by Timoshenko beam idealizations with shear and incorporating simple boundary conditions. The blade was synthesized using the following methods: (1) conjugate gradient minimization of the system Hamiltonian in function space incorporating penalty function transformations, (2) projection operator methods in a function space which includes the frequencies of vibration and the control function, (3) epsilon-technique penalty function transformation resulting in a highly nonlinear programming problem, (4) finite difference discretization of the state equations again resulting in a nonlinear program, (5) second variation methods with complex state differential equations to include damping effects resulting in systems of inhomogeneous matrix Riccatti equations some of which are stiff, (6) quasi-linear methods based on iterative linearization of the state and adjoint equation. The paper includes a discussion of some substantial computational difficulties encountered in the implementation of these techniques together with a resume of work presently in progress using a differential dynamic programming approach.

Instantaneous Doppler Global Velocimetry Measurements of a Rotor Wake: Lessons Learned

NASA Technical Reports Server (NTRS)

Meyers, James; Fleming, Gary A.; Gorton, Susan Althoff; Berry, John D.

1998-01-01

A combined Doppler Global Velocimetry (DGV) and Projection Moir Interferometry (PMI) investigation of a helicopter rotor wake flow field and rotor blade deformation is presented. The three-component DGV system uses a single-frequency, frequency-doubled Nd:YAG laser to obtain instantaneous velocity measurements in the flow. The PMI system uses a pulsed laser-diode bar to obtain blade bending and twist measurements at the same instant that DGV measured the flow. The application of pulse lasers to DGV and PMI in large-scale wind tunnel applications represents a major step forward in the development of these technologies. As such, a great deal was learned about the difficulties of using these instruments to obtain instantaneous measurements in large facilities. Laser speckle and other image noise in the DGV data images were found to be traceable to the Nd:YAG laser. Although image processing techniques were used to virtually eliminate laser speckle noise, the source of low-frequency image noise is still under investigation. The PMI results agreed well with theoretical predictions of blade bending and twist.

Transition modelling implications in the CFD analysis of a turbine nozzle vane cascade tested over a range of Mach and Reynolds numbers

NASA Astrophysics Data System (ADS)

Marconcini, Michele; Pacciani, Roberto; Arnone, Andrea

2015-11-01

The aerodynamic performance of a gas turbine nozzle vane cascade was investigated over a range of Mach and Reynolds numbers. The work is part of a vast research project aimed at the analysis of fluid dynamics and heat transfer phenomena in cooled blades. In this paper computed results on the "solid vane" (without cooling devices) are presented and discussed in comparison with experimental data. Detailed measurements were provided by the University of Bergamo where the experimental campaign was carried out by means of a subsonic wind tunnel. The impact of boundary layer transition is investigated by using a novel laminar kinetic energy transport model and the widely used Langtry-Menter γ- Re θ,t model. The comparison between calculations and measurements is presented in terms of blade loading distributions, total pressure loss coefficient contours downstream of the cascade, and velocity/turbulence-intensity profiles within the boundary layer at selected blade surface locations at mid-span. It will be shown how transitional calculations compare favorably with experiments.

Helicopter far-field acoustic levels as a function of reduced main-rotor advancing blade-tip Mach number

NASA Technical Reports Server (NTRS)

Mueller, Arnold W.; Smith, Charles D.; Lemasurier, Philip

1990-01-01

During the design of a helicopter, the weight, engine, rotor speed, and rotor geometry are given significant attention when considering the specific operations for which the helicopter will be used. However, the noise radiated from the helicopter and its relationship to the design variables is currently not well modeled with only a limited set of full-scale field test data to study. In general, limited field data have shown that reduced main-rotor advancing blade-tip Mach numbers result in reduced far-field noise levels. The status of a recent helicopter noise research project is reviewed. It is designed to provide flight experimental data which may be used to further understand helicopter main-rotor advancing blade-tip Mach number effects on far-field acoustic levels. Preliminary results are presented relative to tests conducted with a Sikorsky S-76A helicopter operating with both the rotor speed and the flight speed as the control variable. The rotor speed was operated within the range of 107 to 90 percent NR at nominal forward speeds of 35, 100, and 155 knots.

The MOD-OA 200 kilowatt wind turbine generator design and analysis report

NASA Astrophysics Data System (ADS)

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-08-01

The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed.

The MOD-OA 200 kilowatt wind turbine generator design and analysis report

NASA Technical Reports Server (NTRS)

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-01-01

The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed.

Energy Efficient Engine acoustic supporting technology report

NASA Technical Reports Server (NTRS)

Lavin, S. P.; Ho, P. Y.

1985-01-01

The acoustic development of the Energy Efficient Engine combined testing and analysis using scale model rigs and an integrated Core/Low Spool demonstration engine. The scale model tests show that a cut-on blade/vane ratio fan with a large spacing (S/C = 2.3) is as quiet as a cut-off blade/vane ratio with a tighter spacing (S/C = 1.27). Scale model mixer tests show that separate flow nozzles are the noisiest, conic nozzles the quietest, with forced mixers in between. Based on projections of ICLS data the Energy Efficient Engine (E3) has FAR 36 margins of 3.7 EPNdB at approach, 4.5 EPNdB at full power takeoff, and 7.2 EPNdB at sideline conditions.

Exploring the Role of Genetic Algorithms and Artificial Neural Networks for Interpolation of Elevation in Geoinformation Models

NASA Astrophysics Data System (ADS)

Bagheri, H.; Sadjadi, S. Y.; Sadeghian, S.

2013-09-01

One of the most significant tools to study many engineering projects is three-dimensional modelling of the Earth that has many applications in the Geospatial Information System (GIS), e.g. creating Digital Train Modelling (DTM). DTM has numerous applications in the fields of sciences, engineering, design and various project administrations. One of the most significant events in DTM technique is the interpolation of elevation to create a continuous surface. There are several methods for interpolation, which have shown many results due to the environmental conditions and input data. The usual methods of interpolation used in this study along with Genetic Algorithms (GA) have been optimised and consisting of polynomials and the Inverse Distance Weighting (IDW) method. In this paper, the Artificial Intelligent (AI) techniques such as GA and Neural Networks (NN) are used on the samples to optimise the interpolation methods and production of Digital Elevation Model (DEM). The aim of entire interpolation methods is to evaluate the accuracy of interpolation methods. Universal interpolation occurs in the entire neighbouring regions can be suggested for larger regions, which can be divided into smaller regions. The results obtained from applying GA and ANN individually, will be compared with the typical method of interpolation for creation of elevations. The resulting had performed that AI methods have a high potential in the interpolation of elevations. Using artificial networks algorithms for the interpolation and optimisation based on the IDW method with GA could be estimated the high precise elevations.

Mercury Science Objectives and Traceability Within the BepiColombo Project: Optimising the Science Output of the Next Mission to Mercury

NASA Astrophysics Data System (ADS)

Besse, S.; Benkhoff, J.; Bentley, M.; Cornet, T.; Moissl, R.; Munoz, C.; Zender, J.

2018-05-01

The BepiColombo Science Ground Segment is developing, in collaboration with the instrument teams, targeted science traceability matrix of each instrument. They are defined in such a way that they can be tracked during the observation lifecycle.

Effect of helicopter blade dynamics on blade aerodynamic and structural loads

NASA Technical Reports Server (NTRS)

Heffernan, Ruth M.

1987-01-01

The effect of rotor blade dynamics on aerodynamic and structural loads is examined for a conventional, main-rotor helicopter using a comprehensive rotorcraft analysis (CAMRAD) and flight-test data. The impact of blade dynamics on blade section lift-coefficient time histories is studied by comparing predictions from a rigid-blade analysis and an elastic-blade analysis with helicopter flight test data. The elastic blade analysis better predicts high-frequency behavior of section lift. In addition, components of the blade angle of attack such as elastic blade twist, blade flap rate, blade slope velocity, and inflow are examined as a function of blade mode. Elastic blade motion changed blade angle of attack by a few tenths of a degree, and up to the sixth rotor harmonic. A similar study of the influence of blade dynamics on bending and torsion moments was also conducted. A correlation study comparing predictions from several elastic-blade analyses with flight-test data revealed that an elastic-blade model consisting of only three elastic bending modes (first and second flap and first lag), and two elastic torsion modes was sufficient for good correlation.

Blade counting tool with a 3D borescope for turbine applications

NASA Astrophysics Data System (ADS)

Harding, Kevin G.; Gu, Jiajun; Tao, Li; Song, Guiju; Han, Jie

2014-07-01

Video borescopes are widely used for turbine and aviation engine inspection to guarantee the health of blades and prevent blade failure during running. When the moving components of a turbine engine are inspected with a video borescope, the operator must view every blade in a given stage. The blade counting tool is video interpretation software that runs simultaneously in the background during inspection. It identifies moving turbine blades in a video stream, tracks and counts the blades as they move across the screen. This approach includes blade detection to identify blades in different inspection scenarios and blade tracking to perceive blade movement even in hand-turning engine inspections. The software is able to label each blade by comparing counting results to a known blade count for the engine type and stage. On-screen indications show the borescope user labels for each blade and how many blades have been viewed as the turbine is rotated.

Advanced Offshore Wind Turbine/Foundation Concept for the Great Lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Afjeh, Abdollah A.; Windpower, Nautica; Marrone, Joseph

2013-08-29

This project investigated a conceptual 2-bladed rotor wind turbine design and assessed its feasibility for installation in the Great Lakes. The levelized cost of energy was used for this purpose. A location in Lake Erie near the coast of Cleveland, Ohio was selected as the application site. The loading environment was defined using wind and wave data collected at a weather station in Lake Erie near Cleveland. In addition, the probability distributions of the annual significant wave height and wind speed were determined. A model of the dependence of the above two quantities was also developed and used in themore » study of wind turbine system loads. Loads from ice floes and ridges were also included.The NREL 5 MW 3-bladed rotor wind turbine concept was used as the baseline design. The proposed turbine design employs variable pitch blade control with tip-brakes and a teeter mechanism. The rotor diameter, rated power and the tower dimensions were selected to closely match those of the NREL 5 MW wind turbine.A semi-floating gravity base foundation was designed for this project primarily to adapt to regional logistical constraints to transport and install the gravity base foundation. This foundation consists of, from bottom to top, a base plate, a buoyancy chamber, a taper zone, a column (with ice cone), and a service platform. A compound upward-downward ice cone was selected to secure the foundation from moving because of ice impact.The turbine loads analysis was based on International ElectroTechnical Committee (IEC) Standard 61400-1, Class III winds. The NREL software FAST was the primary computational tool used in this study to determine all design load cases. An initial set of studies of the dynamics of wind turbines using Automatic Dynamic Analysis of Mechanical Systems (ADAMS) demonstrated that FAST and ADAMS load predictions were comparable. Because of its relative simplicity and short run times, FAST was selected for this study. For ice load calculations, a method was developed and implemented in FAST to extend its capability for ice load modeling.Both upwind and downwind 2-bladed rotor wind turbine designs were developed and studied. The new rotor blade uses a new twist angle distribution design and a new pitch control algorithm compared with the baseline model. The coning and tilt angles were selected for both the upwind and downwind configurations to maximize the annual energy production. The risk of blade-tower impact is greater for the downwind design, particularly under a power grid fault; however, this risk was effectively reduced by adjusting the tilt angle for the downwind configuration.« less

Open Rotor Development

NASA Technical Reports Server (NTRS)

Van Zante, Dale E.; Rizzi, Stephen A.

2016-01-01

The ERA project executed a comprehensive test program for Open Rotor aerodynamic and acoustic performance. System studies used the data to estimate the fuel burn savings and acoustic margin for an aircraft system with open rotor propulsion. The acoustic measurements were used to produce an auralization that compares the legacy blades to the current generation of open rotor designs.

Effect of Helicopter Blade Dynamics on Blade Aerodynamic and Structural Loads

NASA Technical Reports Server (NTRS)

Heffernan, Ruth M.

1987-01-01

The effect of rotor blade dynamics on aerodynamic and structural loads is examined for a conventional, main- rotor helicopter using both a comprehensive rotorcraft analysis (CAMRAD) and night test data. The impact of blade dynamics on blade section lift-coefficient time histories is studied by comparing predictions from both a rigid blade analysis and an elastic blade analysis with helicopter flight test data. The elastic blade analysis better predicts high-frequency behavior of section lift. In addition, components of the blade angle of attack, such as elastic blade twist, blade nap rate, blade slope velocity, and inflow, are examined as a function of blade mode. Elastic blade motion affects the blade angle of attack by a few tenths of a degree, and up to the sixth rotor harmonic. A similar study of the influence of blade dynamics on bending and torsion moments was also conducted. The modal analysis of the predicted blade structural loads suggested that five elastic bending deg of freedom (four flap and one lag) and three elastic torsion deg of freedom contributed to calculations of the blade structural loads. However, when structural bending load predictions from several elastic blade analyses were compared with flight test data, an elastic blade model consisting of only three elastic bending modes (first and second flap, and first lag), and two elastic torsion modes was found to be sufficient for maximum correlation.

NURBS-Based Geometry for Integrated Structural Analysis

NASA Technical Reports Server (NTRS)

Oliver, James H.

1997-01-01

This grant was initiated in April 1993 and completed in September 1996. The primary goal of the project was to exploit the emerging defacto CAD standard of Non- Uniform Rational B-spline (NURBS) based curve and surface geometry to integrate and streamline the process of turbomachinery structural analysis. We focused our efforts on critical geometric modeling challenges typically posed by the requirements of structural analysts. We developed a suite of software tools that facilitate pre- and post-processing of NURBS-based turbomachinery blade models for finite element structural analyses. We also developed tools to facilitate the modeling of blades in their manufactured (or cold) state based on nominal operating shape and conditions. All of the software developed in the course of this research is written in the C++ language using the Iris Inventor 3D graphical interface tool-kit from Silicon Graphics. In addition to enhanced modularity, improved maintainability, and efficient prototype development, this design facilitates the re-use of code developed for other NASA projects and provides a uniform and professional 'look and feel' for all applications developed by the Iowa State Team.

Vibration Characteristics Determined for Stainless Steel Sandwich Panels With a Metal Foam Core for Lightweight Fan Blade Design

NASA Technical Reports Server (NTRS)

Ghosn, Louis J.; Min, James B.; Raj, Sai V.; Lerch, Bradley A.; Holland, Frederic A., Jr.

2004-01-01

The goal of this project at the NASA Glenn Research Center is to provide fan materials that are safer, weigh less, and cost less than the currently used titanium alloy or polymer matrix composite fans. The proposed material system is a sandwich fan construction made up of thin solid face sheets and a lightweight metal foam core. The stiffness of the sandwich structure is increased by separating the two face sheets by the foam layer. The resulting structure has a high stiffness and lighter weight in comparison to the solid facesheet material alone. The face sheets carry the applied in-plane and bending loads (ref. 1). The metal foam core must resist the transverse shear and transverse normal loads, as well as keep the facings supported and working as a single unit. Metal foams have ranges of mechanical properties, such as light weight, impact resistance, and vibration suppression (ref. 2), which makes them more suitable for use in lightweight fan structures. Metal foams have been available for decades (refs. 3 and 4), but the difficulties in the original processes and high costs have prevented their widespread use. However, advances in production techniques and cost reduction have created a new interest in this class of materials (ref. 5). The material chosen for the face sheet and the metal foam for this study was the aerospace-grade stainless steel 17-4PH. This steel was chosen because of its attractive mechanical properties and the ease with which it can be made through the powder metallurgy process (ref. 6). The advantages of a metal foam core, in comparison to a typical honeycomb core, are material isotropy and the ease of forming complex geometries, such as fan blades. A section of a 17-4PH sandwich structure is shown in the following photograph. Part of process of designing any blade is to determine the natural frequencies of the particular blade shape. A designer needs to predict the resonance frequencies of a new blade design to properly identify a useful operating range. Operating a blade at or near the resonance frequencies leads to high-cycle fatigue, which ultimately limits the blade's durability and life. So the aim of this study is to determine the variation of the resonance frequencies for an idealized sandwich blade as a function of its face-sheet thickness, core thickness, and foam density. The finite element method is used to determine the natural frequencies for an idealized rectangular sandwich blade. The proven Lanczos method (ref. 7) is used in the study to extract the natural frequency.

Optimised design for a 1 kJ diode-pumped solid-state laser system

NASA Astrophysics Data System (ADS)

Mason, Paul D.; Ertel, Klaus; Banerjee, Saumyabrata; Phillips, P. Jonathan; Hernandez-Gomez, Cristina; Collier, John L.

2011-06-01

A conceptual design for a kJ-class diode-pumped solid-state laser (DPSSL) system based on cryogenic gas-cooled multislab ceramic Yb:YAG amplifier technology has been developed at the STFC as a building block towards a MJ-class source for inertial fusion energy (IFE) projects such as HiPER. In this paper, we present an overview of an amplifier design optimised for efficient generation of 1 kJ nanosecond pulses at 10 Hz repetition rate. In order to confirm the viability of this technology, a prototype version of this amplifier scaled to deliver 10 J at 10 Hz, DiPOLE, is under development at the Central Laser Facility. A progress update on the status of this system is also presented.

Energy efficiency in membrane bioreactors.

PubMed

Barillon, B; Martin Ruel, S; Langlais, C; Lazarova, V

2013-01-01

Energy consumption remains the key factor for the optimisation of the performance of membrane bioreactors (MBRs). This paper presents the results of the detailed energy audits of six full-scale MBRs operated by Suez Environnement in France, Spain and the USA based on on-site energy measurement and analysis of plant operation parameters and treatment performance. Specific energy consumption is compared for two different MBR configurations (flat sheet and hollow fibre membranes) and for plants with different design, loads and operation parameters. The aim of this project was to understand how the energy is consumed in MBR facilities and under which operating conditions, in order to finally provide guidelines and recommended practices for optimisation of MBR operation and design to reduce energy consumption and environmental impacts.

Adaptor assembly for coupling turbine blades to rotor disks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia-Crespo, Andres Jose; Delvaux, John McConnell

2014-09-23

An adaptor assembly for coupling a blade root of a turbine blade to a root slot of a rotor disk is described. The adaptor assembly includes a turbine blade having a blade root and an adaptor body having an adaptor root. The adaptor body defines a slot having an open end configured to receive the blade root of the turbine blade such that the adaptor root of the adaptor body and the blade root of the turbine blade are adjacent to one another when the blade root of the turbine blade is positioned within the slot. Both the adaptor rootmore » of the adaptor body and the blade root of the turbine blade are configured to be received within the root slot of the rotor disk.« less

Single versus double blade technique for skin incision and deep dissection in surgery for closed fracture: a prospective randomised control study.

PubMed

Trikha, V; Saini, P; Mathur, P; Agarwal, A; Kumar, S V; Choudhary, B

2016-04-01

To compare blade cultures in surgery for closed fracture using a single or double blade technique to determine whether the current practice of double blade technique is justified. 155 men and 29 women aged 20 to 60 (mean, 35) years who underwent surgery for closed fracture with healthy skin at the incision site were included. Patients were block randomised to the single (n=92) or double (n=92) blade technique. Blades were sent for bacteriological analysis. Outcome measures were early surgical site infection (SSI) within 30 days and cultures from the blades. The 2 groups were comparable in baseline characteristics. In the single blade group, 6 surgical blades and 2 control blades showed positive cultures; 4 patients developed SSI, but only one had a positive culture from the surgical blade (with different organism isolated from the wound culture). In the double blade group, 6 skin blades, 7 deep blades, and 0 control blade showed positive culture; only 2 patients had the same bacteria grown from both skin and deep blade. Five patients developed SSI, but only one patient had a positive culture from the deep blade (with different organism isolated from the wound culture). The difference in incidence of culture-positive blade or SSI between the 2 groups was not significant. The relative risk of SSI in the single blade group was 0.8. Positive blade culture was not associated with SSI in the single or double blade group. The practice of changing blade following skin incision has no effect on reducing early SSI in surgery for closed fracture in healthy patients with healthy skin.

Application of snakes and dynamic programming optimisation technique in modeling of buildings in informal settlement areas

NASA Astrophysics Data System (ADS)

Rüther, Heinz; Martine, Hagai M.; Mtalo, E. G.

This paper presents a novel approach to semiautomatic building extraction in informal settlement areas from aerial photographs. The proposed approach uses a strategy of delineating buildings by optimising their approximate building contour position. Approximate building contours are derived automatically by locating elevation blobs in digital surface models. Building extraction is then effected by means of the snakes algorithm and the dynamic programming optimisation technique. With dynamic programming, the building contour optimisation problem is realized through a discrete multistage process and solved by the "time-delayed" algorithm, as developed in this work. The proposed building extraction approach is a semiautomatic process, with user-controlled operations linking fully automated subprocesses. Inputs into the proposed building extraction system are ortho-images and digital surface models, the latter being generated through image matching techniques. Buildings are modeled as "lumps" or elevation blobs in digital surface models, which are derived by altimetric thresholding of digital surface models. Initial windows for building extraction are provided by projecting the elevation blobs centre points onto an ortho-image. In the next step, approximate building contours are extracted from the ortho-image by region growing constrained by edges. Approximate building contours thus derived are inputs into the dynamic programming optimisation process in which final building contours are established. The proposed system is tested on two study areas: Marconi Beam in Cape Town, South Africa, and Manzese in Dar es Salaam, Tanzania. Sixty percent of buildings in the study areas have been extracted and verified and it is concluded that the proposed approach contributes meaningfully to the extraction of buildings in moderately complex and crowded informal settlement areas.

[GeKo KidS--Health Literacy in School Children].

PubMed

Splieth, C H; Franze, M; Plachta-Danielzik, S; Thyrian, J R; Schmidt, C O; John, U; Kohlmann, T; Müller, M J; Hoffmann, W

2015-09-01

The main goal of this study was the evaluation of an intervention programme for the promotion of health literacy in school-aged children (grade 5-6). The project and the programme were highly accepted, the extension of the annual dental health examination was suitable to collect data within evaluation projects in schools. In spite of positive outcomes, a longer supervision phase would be necessary in order to optimise and to implement other programme components fully. © Georg Thieme Verlag KG Stuttgart · New York.

Progress toward determining the potential of ODS alloys for gas turbine applications

NASA Technical Reports Server (NTRS)

Dreshfield, R. L.; Hoppin, G., III; Sheffler, K.

1983-01-01

The Materials for Advanced Turbine Engine (MATE) Program managed by the NASA Lewis Research Center is supporting two projects to evaluate the potential of oxide dispersion strengthened (ODS) alloys for aircraft gas turbine applications. One project involves the evaluation of Incoloy (TM) MA-956 for application as a combustor liner material. An assessment of advanced engine potential will be conducted by means of a test in a P&WA 2037 turbofan engine. The other project involves the evaluation of Inconel (TM) MA 6000 for application as a high pressure turbine blade material and includes a test in a Garrett TFE 731 turbofan engine. Both projects are progressing toward these engine tests in 1984.

Optimization of Surface Roughness and Wall Thickness in Dieless Incremental Forming Of Aluminum Sheet Using Taguchi

NASA Astrophysics Data System (ADS)

Hamedon, Zamzuri; Kuang, Shea Cheng; Jaafar, Hasnulhadi; Azhari, Azmir

2018-03-01

Incremental sheet forming is a versatile sheet metal forming process where a sheet metal is formed into its final shape by a series of localized deformation without a specialised die. However, it still has many shortcomings that need to be overcome such as geometric accuracy, surface roughness, formability, forming speed, and so on. This project focus on minimising the surface roughness of aluminium sheet and improving its thickness uniformity in incremental sheet forming via optimisation of wall angle, feed rate, and step size. Besides, the effect of wall angle, feed rate, and step size to the surface roughness and thickness uniformity of aluminium sheet was investigated in this project. From the results, it was observed that surface roughness and thickness uniformity were inversely varied due to the formation of surface waviness. Increase in feed rate and decrease in step size will produce a lower surface roughness, while uniform thickness reduction was obtained by reducing the wall angle and step size. By using Taguchi analysis, the optimum parameters for minimum surface roughness and uniform thickness reduction of aluminium sheet were determined. The finding of this project helps to reduce the time in optimising the surface roughness and thickness uniformity in incremental sheet forming.

Intubation of prehospital patients with curved laryngoscope blade is more successful than with straight blade.

PubMed

Alter, Scott M; Haim, Eithan D; Sullivan, Alex H; Clayton, Lisa M

2018-02-17

Direct laryngoscopy can be performed using curved or straight blades, and providers usually choose the blade they are most comfortable with. However, curved blades are anecdotally thought of as easier to use than straight blades. We seek to compare intubation success rates of paramedics using curved versus straight blades. Design: retrospective chart review. hospital-based suburban ALS service with 20,000 annual calls. prehospital patients with any direct laryngoscopy intubation attempt over almost 9years. First attempt and overall success rates were calculated for attempts with curved and straight blades. Differences between the groups were calculated. 2299 patients were intubated by direct laryngoscopy. 1865 had attempts with a curved blade, 367 had attempts with a straight blade, and 67 had attempts with both. Baseline characteristics were similar between groups. First attempt success was 86% with a curved blade and 73% with a straight blade: a difference of 13% (95% CI: 9-17). Overall success was 96% with a curved blade and 81% with a straight blade: a difference of 15% (95% CI: 12-18). There was an average of 1.11 intubation attempts per patient with a curved blade and 1.13 attempts per patient with a straight blade (2% difference, 95% CI: -3-7). Our study found a significant difference in intubation success rates between laryngoscope blade types. Curved blades had higher first attempt and overall success rates when compared to straight blades. Paramedics should consider selecting a curved blade as their tool of choice to potentially improve intubation success. Copyright © 2018 Elsevier Inc. All rights reserved.

AnswerPro: Designing to Motivate Interaction

ERIC Educational Resources Information Center

AlSugair, Balsam; Hopkins, Gail; FitzGerald, Elizabeth; Brailsford, Tim

2014-01-01

This paper describes the design and initial testing of AnswerPro, a mobile academic peer support system for school pupils aged 11-16 years. AnswerPro is a mobile optimised web application that enables pupils to seek support with school work from knowledgeable peers on various subjects. This paper presents research findings from the project, and in…

Measurements on the Magdalen Islands VAWT and future projects

NASA Astrophysics Data System (ADS)

Gallagher, N. C.; Rangi, R. S.

The rotor of a 224 kW vertical axis wind turbine (VAWT) is discussed. The rebuilt rotor of the 224 kW Magdalen Islands VAWT was installed in Sept. 1979 and is operating at its design speed (36.6 rpm). Agreement between measured and theoretical performance is generally good except that maximum power may exceed theoretical predictions. Measurements of drive train losses, torque and power ripple, and rotor stresses are discussed. Although peak-to-peak cyclic stress levels are low in relation to fatigue life limits, spectral analysis of stress data indicates that the 3-per-rev component is amplified by near-resonance with the first butterfly blade mode. This resonance was subsequently de-coupled by a damped connection between the blade struts and the central column.

KSC-2012-5577

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - Astronauts Mike Fossum and Cady Coleman, both in blue flight suits, look over the model capsule fit with rotor blades ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center Aerospace Engineer Jeff Hagen, right, fields questions about the project. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

Effect of Control Blade History, and Axial Coolant Density and Burnup Profiles on BWR Burnup Credit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ade, Brian J; Marshall, William BJ J; Martinez-Gonzalez, Jesus S

Oak Ridge National Laboratory (ORNL) and the US Nuclear Regulatory Commission (NRC) have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling water reactor (BWR) fuel in storage and transportation systems (often referred to as casks) and spent fuel pools (SFPs). This work is divided into two main phases. The first phase investigated the applicability of peak reactivity methods currently used in SFPs to transportation and storage casks and the validation of reactivity calculations and spent fuel compositions within these methods. The second phase focuses on extending BUC beyond peak reactivity. This paper documents themore » analysis of the effects of control blade insertion history, and moderator density and burnup axial profiles for extended BWR BUC.« less

Reconstruction method for running shape of rotor blade considering nonlinear stiffness and loads

NASA Astrophysics Data System (ADS)

Wang, Yongliang; Kang, Da; Zhong, Jingjun

2017-10-01

The aerodynamic and centrifugal loads acting on the rotating blade make the blade configuration deformed comparing to its shape at rest. Accurate prediction of the running blade configuration plays a significant role in examining and analyzing turbomachinery performance. Considering nonlinear stiffness and loads, a reconstruction method is presented to address transformation of a rotating blade from cold to hot state. When calculating blade deformations, the blade stiffness and load conditions are updated simultaneously as blade shape varies. The reconstruction procedure is iterated till a converged hot blade shape is obtained. This method has been employed to determine the operating blade shapes of a test rotor blade and the Stage 37 rotor blade. The calculated results are compared with the experiments. The results show that the proposed method used for blade operating shape prediction is effective. The studies also show that this method can improve precision of finite element analysis and aerodynamic performance analysis.

Articulated limiter blade for a tokamak fusion reactor

DOEpatents

Doll, D.W.

1982-10-21

A limiter blade for a large tokomak fusion reactor includes three articulated blade sections for enabling the limiter blade to be adjusted for plasmas of different sizes. Each blade section is formed of a rigid backing plate carrying graphite tiles coated with titanium carbide, and the limiter blade forms a generally elliptic contour in both the poloidal and toroidal directions to uniformly distribute the heat flow to the blade. The limiter blade includes a central blade section movable along the major radius of the vacuum vessel, and upper and lower pivotal blade sections which may be pivoted by linear actuators having rollers held to the back surface of the pivotal blade sections.

Articulated limiter blade for a tokamak fusion reactor

DOEpatents

Doll, David W.

1985-01-01

A limiter blade for a large tokomak fusion reactor includes three articulated blade sections for enabling the limiter blade to be adjusted for plasmas of different sizes. Each blade section is formed of a rigid backing plate carrying graphite tiles coated with titanium carbide, and the limiter blade forms a generally elliptic contour in both the poloidal and toroidal directions to uniformly distribute the heat flow to the blade. The limiter blade includes a central blade section movable along the major radius of the vacuum vessel, and upper and lower pivotal blade sections which may be pivoted by linear actuators having rollers held to the back surface of the pivotal blade sections.

Structural tailoring of engine blades (STAEBL) user's manual

NASA Technical Reports Server (NTRS)

Brown, K. W.

1985-01-01

This User's Manual contains instructions and demonstration case to prepare input data, run, and modify the Structural Tailoring of Engine Blades (STAEBL) computer code. STAEBL was developed to perform engine fan and compressor blade numerical optimizations. This blade optimization seeks a minimum weight or cost design that satisfies realistic blade design constraints, by tuning one to twenty design variables. The STAEBL constraint analyses include blade stresses, vibratory response, flutter, and foreign object damage. Blade design variables include airfoil thickness at several locations, blade chord, and construction variables: hole size for hollow blades, and composite material layup for composite blades.

Large eddy simulation for predicting turbulent heat transfer in gas turbines.

PubMed

Tafti, Danesh K; He, Long; Nagendra, K

2014-08-13

Blade cooling technology will play a critical role in the next generation of propulsion and power generation gas turbines. Accurate prediction of blade metal temperature can avoid the use of excessive compressed bypass air and allow higher turbine inlet temperature, increasing fuel efficiency and decreasing emissions. Large eddy simulation (LES) has been established to predict heat transfer coefficients with good accuracy under various non-canonical flows, but is still limited to relatively simple geometries and low Reynolds numbers. It is envisioned that the projected increase in computational power combined with a drop in price-to-performance ratio will make system-level simulations using LES in complex blade geometries at engine conditions accessible to the design process in the coming one to two decades. In making this possible, two key challenges are addressed in this paper: working with complex intricate blade geometries and simulating high-Reynolds-number (Re) flows. It is proposed to use the immersed boundary method (IBM) combined with LES wall functions. A ribbed duct at Re=20 000 is simulated using the IBM, and a two-pass ribbed duct is simulated at Re=100 000 with and without rotation (rotation number Ro=0.2) using LES with wall functions. The results validate that the IBM is a viable alternative to body-conforming grids and that LES with wall functions reproduces experimental results at a much lower computational cost. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Reciprocal peer review for quality improvement: an ethnographic case study of the Improving Lung Cancer Outcomes Project.

PubMed

Aveling, Emma-Louise; Martin, Graham; Jiménez García, Senai; Martin, Lisa; Herbert, Georgia; Armstrong, Natalie; Dixon-Woods, Mary; Woolhouse, Ian

2012-12-01

Peer review offers a promising way of promoting improvement in health systems, but the optimal model is not yet clear. We aimed to describe a specific peer review model-reciprocal peer-to-peer review (RP2PR)-to identify the features that appeared to support optimal functioning. We conducted an ethnographic study involving observations, interviews and documentary analysis of the Improving Lung Cancer Outcomes Project, which involved 30 paired multidisciplinary lung cancer teams participating in facilitated reciprocal site visits. Analysis was based on the constant comparative method. Fundamental features of the model include multidisciplinary participation, a focus on discussion and observation of teams in action, rather than paperwork; facilitated reflection and discussion on data and observations; support to develop focused improvement plans. Five key features were identified as important in optimising this model: peers and pairing methods; minimising logistic burden; structure of visits; independent facilitation; and credibility of the process. Facilitated RP2PR was generally a positive experience for participants, but implementing improvement plans was challenging and required substantial support. RP2PR appears to be optimised when it is well organised; a safe environment for learning is created; credibility is maximised; implementation and impact are supported. RP2PR is seen as credible and legitimate by lung cancer teams and can act as a powerful stimulus to produce focused quality improvement plans and to support implementation. Our findings have identified how RP2PR functioned and may be optimised to provide a constructive, open space for identifying opportunities for improvement and solutions.

In-Situ Subsurface Coating of Corroded Steel Sheet Pile Structures: Final Report on Project F08-AR06

DTIC Science & Technology

2017-09-01

scraped the sheet pile wall with an excavator. After scraping the out-pans with a flat edge bucket, the contractor welded a blade on the bucket...unusual striations were parallel grooves running at 30 – 45 degrees from the vertical. Some patterns cross each other symmetrically. The stria- tions

76 FR 30341 - Town of Edgartown; Notice of Preliminary Permit Application Accepted for Filing and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-25

...), filed an application for a successive preliminary permit, pursuant to section 4(f) of the Federal Power Act (FPA), proposing to study the feasibility of the Muskeget Channel Tidal Energy Project to be..., and one experimental turbine unit that would be used to test various open- bladed and helical tidal...

Comparison of the effects of 23-gauge and 25-gauge microincision vitrectomy blade designs on incision architecture.

PubMed

Inoue, Makoto; Abulon, Dina Joy K; Hirakata, Akito

2014-01-01

To compare the effects of different 23- and 25-gauge microincision vitrectomy trocar cannula entry systems on incision architecture. We tested one ridged microvitreoretinal (MVR), one non-ridged MVR, one pointed beveled, and one round-tipped beveled blade (n=10 per blade design per incision type). Each blade's straight and oblique incision architecture was assessed in a silicone disc simulating the sclera. Wound leakage under pressure and endoscopic observations were conducted on sclerotomy sites of isolated porcine eyes (n=4 per blade design) after simulated vitrectomy. Differences in blade design created distinct incision architecture. Incisions were linear with the ridged MVR blade, flattened "M-shaped" with the non-ridged MVR blade, asymmetrical chevron-shaped with the pointed beveled blade, and curved with the round-tipped beveled blade. With the exception of oblique entry incision thickness, both MVR blade designs created thinner incisions than the beveled blades at entry and exit sites. Only the ridged MVR blade created incisions with no leakage. Vitreous incarceration was observed with all trocar cannula systems. Wound closure in porcine eyes was similar with all blades despite differences in incision architecture. Wound leakage occurred at low to moderate infusion pressures with most blades; no wound leakage was observed with ridged MVR blades.

Flexible Blades for Wind Turbines

NASA Astrophysics Data System (ADS)

Collins, Madeline Carlisle; Macphee, David; Harris, Caleb

2016-11-01

Previous research has shown that windmills with flexible blades are more efficient than those with rigid blades. Flexibility offers passive pitch control, preferable to active pitch control which is costly and requires maintenance. Flexible blades morph such that the blade more closely resembles its design point at part load and over load. The lift-to-drag ratios on individual blades was investigated. A mold was designed and machined from an acrylic slab for the casting of blades with a NACA 0012 cross section. A flexible blade was cast from silicone and a rigid blade was cast from polyurethane. Each of these blades was tested in a wind tunnel, cantilever mounted, spanning the whole test section. The angle of attack was varied by rotating the mount. All tests were performed at the same wind speed. A load cell within the mount measured forces on the blade, from which the lift and drag forces were calculated. The stall point for the flexible blade occurred later than for the rigid blade, which agrees with previous research. Lift-to-drag ratios were larger for the flexible blade at all angles of attack tested. Flexible blades seem to be a viable option for passive pitch control. Future research will include different airfoil cross sections, wind speeds, and blade materials. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

Estimation of the energy loss at the blades in rowing: common assumptions revisited.

PubMed

Hofmijster, Mathijs; De Koning, Jos; Van Soest, A J

2010-08-01

In rowing, power is inevitably lost as kinetic energy is imparted to the water during push-off with the blades. Power loss is estimated from reconstructed blade kinetics and kinematics. Traditionally, it is assumed that the oar is completely rigid and that force acts strictly perpendicular to the blade. The aim of the present study was to evaluate how reconstructed blade kinematics, kinetics, and average power loss are affected by these assumptions. A calibration experiment with instrumented oars and oarlocks was performed to establish relations between measured signals and oar deformation and blade force. Next, an on-water experiment was performed with a single female world-class rower rowing at constant racing pace in an instrumented scull. Blade kinematics, kinetics, and power loss under different assumptions (rigid versus deformable oars; absence or presence of a blade force component parallel to the oar) were reconstructed. Estimated power losses at the blades are 18% higher when parallel blade force is incorporated. Incorporating oar deformation affects reconstructed blade kinematics and instantaneous power loss, but has no effect on estimation of power losses at the blades. Assumptions on oar deformation and blade force direction have implications for the reconstructed blade kinetics and kinematics. Neglecting parallel blade forces leads to a substantial underestimation of power losses at the blades.

The Sharpness of Blades Used in Dermatologic Surgery.

PubMed

Awadalla, Farah; Hexsel, Camile; Goldberg, Leonard H

2016-01-01

There are numerous blades available for use in dermatologic procedures. There are different advantages that are inhere.nt to different blades due to their shape and size. One aspect of the blade that is instrumental to its performance, but is not objectively defined, is sharpness. This information could be useful when choosing a blade for a particular procedure. This study aims to objectively define the sharpness of blades used in dermatologic surgery. The Sharpness Tester (Cutlery and Allied Trades Research Association, Sheffield, UK) was used to test the force in Newtons a blade requires to cut through a silicone cylinder. New blades were used to determine a standard for the sharpness of new blades. Blades used for surgery were tested to determine the sharpness after use. The sharpest blade is the double-edged razor blade (0.395 N) followed by the dermablade (0.46 N), plastic handled #15 (0.541 N), #15c (0.575 N), #10 (0.647 N), and the #15 blade (0.664 N). The sharpness of a blade is an important factor in its ability to perform a task and should be taken into account when choosing a particular blade for a particular procedure.

Design and fabrication of forward-swept counterrotation blade configuration for wind tunnel testing

NASA Technical Reports Server (NTRS)

Nichols, G. H.

1994-01-01

Work performed by GE Aircraft on advanced counterrotation blade configuration concepts for high speed turboprop system is described. Primary emphasis was placed on theoretically and experimentally evaluating the aerodynamic, aeromechanical, and acoustic performance of GE-defined counterrotating blade concepts. Several blade design concepts were considered. Feasibility studies were conducted to evaluate a forward-swept versus an aft-swept blade application and how the given blade design would affect interaction between rotors. Two blade designs were initially selected. Both designs involved in-depth aerodynamic, aeromechanical, mechanical, and acoustic analyses followed by the fabrication of forward-swept, forward rotor blade sets to be wind tunnel tested with an aft-swept, aft rotor blade set. A third blade set was later produced from a NASA design that was based on wind tunnel test results from the first two blade sets. This blade set had a stiffer outer ply material added to the original blade design, in order to reach the design point operating line. Detailed analyses, feasibility studies, and fabrication procedures for all blade sets are presented.

Counterrotatable booster compressor assembly for a gas turbine engine

NASA Technical Reports Server (NTRS)

Moniz, Thomas Ory (Inventor); Orlando, Robert Joseph (Inventor)

2004-01-01

A counterrotatable booster compressor assembly for a gas turbine engine having a counterrotatable fan section with a first fan blade row connected to a first drive shaft and a second fan blade row axially spaced from the first fan blade row and connected to a second drive shaft, the counterrotatable booster compressor assembly including a first compressor blade row connected to the first drive shaft and a second compressor blade row interdigitated with the first compressor blade row and connected to the second drive shaft. A portion of each fan blade of the second fan blade row extends through a flowpath of the counterrotatable booster compressor so as to function as a compressor blade in the second compressor blade row. The counterrotatable booster compressor further includes a first platform member integral with each fan blade of the second fan blade row at a first location so as to form an inner flowpath for the counterrotatable booster compressor and a second platform member integral with each fan blade of the second fan blade row at a second location so as to form an outer flowpath for the counterrotatable booster compressor.

The effect of forward skewed rotor blades on aerodynamic and aeroacoustic performance of axial-flow fan

NASA Astrophysics Data System (ADS)

Wei, Jun; Zhong, Fangyuan

Based on comparative experiment, this paper deals with using tangentially skewed rotor blades in axial-flow fan. It is seen from the comparison of the overall performance of the fan with skewed bladed rotor and radial bladed rotor that the skewed blades operate more efficiently than the radial blades, especially at low volume flows. Meanwhile, decrease in pressure rise and flow rate of axial-flow fan with skewed rotor blades is found. The rotor-stator interaction noise and broadband noise of axial-flow fan are reduced with skewed rotor blades. Forward skewed blades tend to reduce the accumulation of the blade boundary layer in the tip region resulting from the effect of centrifugal forces. The turning of streamlines from the outer radius region into inner radius region in blade passages due to the radial component of blade forces of skewed blades is the main reason for the decrease in pressure rise and flow rate.

Numerical study of aero-excitation of steam-turbine rotor blade self-oscillations

NASA Astrophysics Data System (ADS)

Galaev, S. A.; Makhnov, V. Yu.; Ris, V. V.; Smirnov, E. M.

2018-05-01

Blade aero-excitation increment is evaluated by numerical solution of the full 3D unsteady Reynolds-averaged Navier-Stokes equations governing wet steam flow in a powerful steam-turbine last stage. The equilibrium wet steam model was adopted. Blade surfaces oscillations are defined by eigen-modes of a row of blades bounded by a shroud. Grid dependency study was performed with a reduced model being a set of blades multiple an eigen-mode nodal diameter. All other computations were carried out for the entire blade row. Two cases are considered, with an original-blade row and with a row of modified (reinforced) blades. Influence of eigen-mode nodal diameter and blade reinforcing on aero-excitation increment is analyzed. It has been established, in particular, that maximum value of the aero-excitation increment for the reinforced-blade row is two times less as compared with the original-blade row. Generally, results of the study point definitely to less probability of occurrence of blade self-oscillations in case of the reinforced blade-row.

Pose determination of a blade implant in three dimensions from a single two-dimensional radiograph.

PubMed

Toti, Paolo; Barone, Antonio; Marconcini, Simone; Menchini-Fabris, Giovanni Battista; Martuscelli, Ranieri; Covani, Ugo

2018-05-01

The aim of the study was to introduce a mathematical method to estimate the correct pose of a blade by evaluating the radiographic features obtained from a single two-dimensional image. Blade-form implant bed preparation was performed using the piezosurgery device, and placement was attained with the use of magnetic mallet. The pose determination of the blade was described by means of three consecutive rotations defined by three angles of orientation (triplet φ, θ and ψ). Retrospective analysis on periapical radiographs was performed. This method was used to compare implant (axial length along the marker, i.e. the implant structure) vs angular correction factor (a trigonometric function of the triplet). The accuracy of the method was tested by generating two-dimensional radiographic simulations of the blades, which were then compared with the images of the implants as appearing on the real radiographs. Two patients had to be excluded from further evaluation because the values of the estimated pose angles showed a too-wide range to be effective for a good standardization of serial radiographs: intrapatient range from baseline to 1-year survey was > of a threshold determined by the clinicians (30°). The linear dependence between implant (CF°) and angular correction factor (CF^) was estimated by a robust linear regression, yielding the following coefficients: slope, 0.908; intercept, -0.092; and coefficient of determination, 0.924. The absolute error in accuracy was -0.29 ± 4.35, 0.23 ± 3.81 and 0.64 ± 1.18°, respectively, for the angles φ, θ and ψ. The present theoretical and experimental study established the possibility of determining, a posteriori, a unique triplet of angles (φ, θ and ψ) which described the pose of a blade upon a single two-dimensional radiograph, and of suggesting a method to detect cases in which the standardized geometric projection failed. The angular correction of the bone level yielded results very close to those obtained with an internal marker related to the implant length.

Upstream Optioneering: Optimising Higher Activity Waste Management

DOE Office of Scientific and Technical Information (OSTI.GOV)

McTeer, Jennifer; Morris, Jenny; Wickham, Stephen

2013-07-01

The Upstream Optioneering project was created by the Nuclear Decommissioning Authority (NDA) Radioactive Waste Management Directorate (RWMD) to support the development and implementation of opportunities to optimise the management of UK higher activity waste, spent fuel and other materials that may be disposed of in a geological disposal facility. The project works in an integrative manner with the NDA, RWMD and waste producers, and was split into three phases: - In Phase 1 waste management opportunities were identified and collated from across the NDA estate. - In Phase 2, opportunities collated during Phase 1, were further consolidated, analysed and prioritisedmore » to develop a three year work programme. Prioritisation ensured that resources were deployed appropriately and opportunities can be realised before the potential benefit diminishes. - Phase 3, which began in April 2012, comprises a three year work programme to address the prioritised opportunities. Work varies from direct implementation of opportunities to scoping studies that may pave the way for more detailed subsequent work by Site Licence Companies. The work programme is flexible and, subject to change control, varies depending on the needs of project sponsors (RWMD, NDA Strategy and NDA Delivery). This paper provides an overview of the Upstream Optioneering project (focusing particularly on Phases 2 and 3), summarises work carried out to date within the three year work programme, and provides some examples of the main findings concerning specific opportunities from Year One of the Phase 3 work programme. (authors)« less

Adjoint-Baed Optimal Control on the Pitch Angle of a Single-Bladed Vertical-Axis Wind Turbine

NASA Astrophysics Data System (ADS)

Tsai, Hsieh-Chen; Colonius, Tim

2017-11-01

Optimal control on the pitch angle of a NACA0018 single-bladed vertical-axis wind turbine (VAWT) is numerically investigated at a low Reynolds number of 1500. With fixed tip-speed ratio, the input power is minimized and mean tangential force is maximized over a specific time horizon. The immersed boundary method is used to simulate the two-dimensional, incompressible flow around a horizontal cross section of the VAWT. The problem is formulated as a PDE constrained optimization problem and an iterative solution is obtained using adjoint-based conjugate gradient methods. By the end of the longest control horizon examined, two controls end up with time-invariant pitch angles of about the same magnitude but with the opposite signs. The results show that both cases lead to a reduction in the input power but not necessarily an enhancement in the mean tangential force. These reductions in input power are due to the removal of a power-damaging phenomenon that occurs when a vortex pair is captured by the blade in the upwind-half region of a cycle. This project was supported by Caltech FLOWE center/Gordon and Betty Moore Foundation.

The environmental impact of the use of large wind turbines

NASA Astrophysics Data System (ADS)

Manning, P. T.

The existing data base on the environmental impact of large wind energy conversion systems (WECS) is explored. The maximum blade throw distance has been calculated at 850 m, with a 5% probability of more than 300 m. Good design and inspection procedures reduce the risk. Ice throw can be prevented by aircraft deicing techniques, but detectors are still necessary. TV interference is ameliorated by the use of composite blades and directional antennas, by relocating the nearst transmission or relay station, or by introduction of cable TV. Microwave transmission effects can be avoided by careful siting of WECS in a favorable line of sight whenever within 1 km of a transmitter. Visual impact studies have produced few adverse opinions. Noise has not proved an intractable problem, although 30 dB levels have been exceeded 2100 m downwind of the Mod 2 WECS. Further studies are necessary on the effects of heightened ground turbulence produced by large WECS. It is expected that few birds will be harmed by slowly rotating blades in the birds' natural domain, a projection confirmed by sporadic studies. Finally, aircraft collisions are regarded as unlikely and actual land use, mostly confined to rural areas, is minimal.

Effects of Rotor Blade Scaling on High-Pressure Turbine Unsteady Loading

NASA Astrophysics Data System (ADS)

Lastiwka, Derek; Chang, Dongil; Tavoularis, Stavros

2013-03-01

The present work is a study of the effects of rotor blade scaling of a single-stage high pressure turbine on the time-averaged turbine performance and on parameters that influence vibratory stresses on the rotor blades and stator vanes. Three configurations have been considered: a reference case with 36 rotor blades and 24 stator vanes, a case with blades upscaled by 12.5%, and a case with blades downscaled by 10%. The present results demonstrate that blade scaling effects were essentially negligible on the time-averaged turbine performance, but measurable on the unsteady surface pressure fluctuations, which were intensified as blade size was increased. In contrast, blade torque fluctuations increased significantly as blade size decreased. Blade scaling effects were also measurable on the vanes.

77 FR 20518 - Airworthiness Directives; Agusta S.p.A. Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-05

... intended to prevent loss of the blade tip weight, loss of a blade, and subsequent loss of control of the... airworthy blade. This AD is prompted by incidents where a blade tip weight separated from a blade in flight... a blade tip weight separating from a blade in flight, and the subsequent investigation showed that...

ICE CONTROL - Towards optimizing wind energy production during icing events

NASA Astrophysics Data System (ADS)

Dorninger, Manfred; Strauss, Lukas; Serafin, Stefano; Beck, Alexander; Wittmann, Christoph; Weidle, Florian; Meier, Florian; Bourgeois, Saskia; Cattin, René; Burchhart, Thomas; Fink, Martin

2017-04-01

Forecasts of wind power production loss caused by icing weather conditions are produced by a chain of physical models. The model chain consists of a numerical weather prediction model, an icing model and a production loss model. Each element of the model chain is affected by significant uncertainty, which can be quantified using targeted observations and a probabilistic forecasting approach. In this contribution, we present preliminary results from the recently launched project ICE CONTROL, an Austrian research initiative on measurements, probabilistic forecasting, and verification of icing on wind turbine blades. ICE CONTROL includes an experimental field phase, consisting of measurement campaigns in a wind park in Rhineland-Palatinate, Germany, in the winters 2016/17 and 2017/18. Instruments deployed during the campaigns consist of a conventional icing detector on the turbine hub and newly devised ice sensors (eologix Sensor System) on the turbine blades, as well as meteorological sensors for wind, temperature, humidity, visibility, and precipitation type and spectra. Liquid water content and spectral characteristics of super-cooled water droplets are measured using a Fog Monitor FM-120. Three cameras document the icing conditions on the instruments and on the blades. Different modelling approaches are used to quantify the components of the model-chain uncertainties. The uncertainty related to the initial conditions of the weather prediction is evaluated using the existing global ensemble prediction system (EPS) of the European Centre for Medium-Range Weather Forecasts (ECMWF). Furthermore, observation system experiments are conducted with the AROME model and its 3D-Var data assimilation to investigate the impact of additional observations (such as Mode-S aircraft data, SCADA data and MSG cloud mask initialization) on the numerical icing forecast. The uncertainty related to model formulation is estimated from multi-physics ensembles based on the Weather Research and Forecasting model (WRF) by perturbing parameters in the physical parameterization schemes. In addition, uncertainties of the icing model and of its adaptations to the rotating turbine blade are addressed. The model forecasts combined with the suite of instruments and their measurements make it possible to conduct a step-wise verification of all the components of the model chain - a novel aspect compared to similar ongoing and completed forecasting projects.

Axial compressor blade design for desensitization of aerodynamic performance and stability to tip clearance

NASA Astrophysics Data System (ADS)

Erler, Engin

Tip clearance flow is the flow through the clearance between the rotor blade tip and the shroud of a turbomachine, such as compressors and turbines. This flow is driven by the pressure difference across the blade (aerodynamic loading) in the tip region and is a major source of loss in performance and aerodynamic stability in axial compressors of modern aircraft engines. An increase in tip clearance, either temporary due to differential radial expansion between the blade and the shroud during transient operation or permanent due to engine wear or manufacturing tolerances on small blades, increases tip clearance flow and results in higher fuel consumption and higher risk of engine surge. A compressor design that can reduce the sensitivity of its performance and aerodynamic stability to tip clearance increase would have a major impact on short and long-term engine performance and operating envelope. While much research has been carried out on improving nominal compressor performance, little had been done on desensitization to tip clearance increase beyond isolated observations that certain blade designs such as forward chordwise sweep, seem to be less sensitive to tip clearance size increase. The current project aims to identify through a computational study the flow features and associated mechanisms that reduces sensitivity of axial compressor rotors to tip clearance size and propose blade design strategies that can exploit these results. The methodology starts with the design of a reference conventional axial compressor rotor followed by a parametric study with variations of this reference design through modification of the camber line and of the stacking line of blade profiles along the span. It is noted that a simple desensitization method would be to reduce the aerodynamic loading of the blade tip which would reduce the tip clearance flow and its proportional contribution to performance loss. However, with the larger part of the work on the flow done in this region, this approach would entail a nominal performance penalty. Therefore, the chosen rotor design philosophy aims to keep the spanwise loading constant to avoid trading performance for desensitization. The rotor designs that resulted from this exercise are simulated in ANSYS CFX at different tip clearance sizes. The change in their performance with respect to tip clearance size (sensitivity) is compared both on an integral level in terms of pressure ratio and adiabatic efficiency, as well as on a detailed level in terms of aerodynamic losses and blockage associated with tip clearance flow. The sensitivity of aerodynamic stability is evaluated either directly through the simulations of the rotor characteristics up to the stall point (expensive in time and resources) for a few designs or indirectly through the position of the interface between the incoming and tip clearance flow with respect to the rotor leading edge plane. The latter approach is based on a generally observed stall criteria in modern axial compressors. The rotor designs are then assessed according to their sensitivity in comparison to that of the reference rotor design to detect features that can explain the trend in sensitivity to tip clearance size. These features can then be validated and the associated flow mechanisms explained through numerical simulations and modelling. Analysis of the database from the rotor parametric study shows that the observed trend in sensitivity cannot be explained by the shifting of the aerodynamic loading along the blade chord, as initially hypothesized based on the literature review. Instead, two flow features are found to reduce sensitivity of performance and stability to tip clearance, namely an increase in incoming meridional momentum in the tip region and a reduction/elimination of double leakage flow. Double leakage flow is the flow that exits the tip clearance of one blade and proceeds into the clearance of the adjacent blade rather than convecting downstream out of the local blade passage. These flow features are isolated and validated based on the reference rotor design through changes in the inlet total pressure condition to alter incoming flow momentum and blade number count to change double leakage rate. In terms of flow mechanism, double leakage is shown to be detrimental to performance and stability, and its proportional increase with tip clearance size explains the sensitivity increase in the presence of double leakage and, conversely, the desensitization effect of reducing or eliminating double leakage. The increase in incoming meridional momentum in the tip region reduces sensitivity to tip clearance through its reduction of double leakage as well as through improved mixing with tip clearance flow, as demonstrated by an analytical model without double leakage flow. The above results imply that any blade design strategy that exploits the two desensitizing flow features would reduce the performance and stability sensitivity to tip clearance size. The increase of the incoming meridional momentum can be achieved through forward chordwise sweep of the blade. The reduction of double leakage without changing blade pitch can be obtained by decreasing the blade stagger angle in the tip region. Examples of blade designs associated with these strategies are shown through CFX simulations to be successful in reducing sensitivity to tip clearance size.

Impact resistant boron/aluminum composites for large fan blades

NASA Technical Reports Server (NTRS)

Oller, T. L.; Salemme, C. T.; Bowden, J. H.; Doble, G. S.; Melnyk, P.

1977-01-01

Blade-like specimens were subjected to static ballistic impact testing to determine their relative FOD impact resistance levels. It was determined that a plus or minus 15 deg layup exhibited good impact resistance. The design of a large solid boron/aluminum fan blade was conducted based on the FOD test results. The CF6 fan blade was used as a baseline for these design studies. The solid boron/aluminum fan blade design was used to fabricate two blades. This effort enabled the assessment of the scale up of existing blade manufacturing details for the fabrication of a large B/Al fan blade. Existing CF6 fan blade tooling was modified for use in fabricating these blades.

Improving linear transport infrastructure efficiency by automated learning and optimised predictive maintenance techniques (INFRALERT)

NASA Astrophysics Data System (ADS)

Jiménez-Redondo, Noemi; Calle-Cordón, Alvaro; Kandler, Ute; Simroth, Axel; Morales, Francisco J.; Reyes, Antonio; Odelius, Johan; Thaduri, Aditya; Morgado, Joao; Duarte, Emmanuele

2017-09-01

The on-going H2020 project INFRALERT aims to increase rail and road infrastructure capacity in the current framework of increased transportation demand by developing and deploying solutions to optimise maintenance interventions planning. It includes two real pilots for road and railways infrastructure. INFRALERT develops an ICT platform (the expert-based Infrastructure Management System, eIMS) which follows a modular approach including several expert-based toolkits. This paper presents the methodologies and preliminary results of the toolkits for i) nowcasting and forecasting of asset condition, ii) alert generation, iii) RAMS & LCC analysis and iv) decision support. The results of these toolkits in a meshed road network in Portugal under the jurisdiction of Infraestruturas de Portugal (IP) are presented showing the capabilities of the approaches.

Air-Cooled Turbine Blades with Tip Cap For Improved Leading-Edge Cooling

NASA Technical Reports Server (NTRS)

Calvert, Howard F.; Meyer, Andre J., Jr.; Morgan, William C.

1959-01-01

An investigation was conducted in a modified turbojet engine to determine the cooling characteristics of the semistrut corrugated air- cooled turbine blade and to compare and evaluate a leading-edge tip cap as a means for improving the leading-edge cooling characteristics of cooled turbine blades. Temperature data were obtained from uncapped air-cooled blades (blade A), cooled blades with the leading-edge tip area capped (blade B), and blades with slanted corrugations in addition to leading-edge tip caps (blade C). All data are for rated engine speed and turbine-inlet temperature (1660 F). A comparison of temperature data from blades A and B showed a leading-edge temperature reduction of about 130 F that could be attributed to the use of tip caps. Even better leading-edge cooling was obtained with blade C. Blade C also operated with the smallest chordwise temperature gradients of the blades tested, but tip-capped blade B operated with the lowest average chordwise temperature. According to a correlation of the experimental data, all three blade types 0 could operate satisfactorily with a turbine-inlet temperature of 2000 F and a coolant flow of 3 percent of engine mass flow or less, with an average chordwise temperature limit of 1400 F. Within the range of coolant flows investigated, however, only blade C could maintain a leading-edge temperature of 1400 F for a turbine-inlet temperature of 2000 F.

Seagrass blade motion under waves and its impact on wave decay

NASA Astrophysics Data System (ADS)

Luhar, M.; Infantes, E.; Nepf, H.

2017-05-01

The hydrodynamic drag generated by seagrass meadows can dissipate wave-energy, causing wave decay. It is well known that this drag depends on the relative motion between the water and the seagrass blades, yet the impact of blade motion on drag and wave-energy dissipation remains to be fully characterized. In this experimental study, we examined the impact of blade motion on wave decay by concurrently recording blade posture during a wave cycle and measuring wave decay over a model seagrass meadow. We also identified a scaling law that predicts wave decay over the model meadow for a range of seagrass blade density, wave period, wave height, and water depth scaled from typical field conditions. Blade flexibility led to significantly lower drag and wave decay relative to theoretical predictions for rigid, upright blades. To quantify the impact of blade motion on wave decay, we employed an effective blade length, le, defined as the rigid blade length that leads to equivalent wave-energy dissipation. We estimated le directly from images of blade motion. Consistent with previous studies, these estimates showed that the effective blade length depends on the dimensionless Cauchy number, which describes the relative magnitude of the wave hydrodynamic drag and the restoring force due to blade rigidity. As the hydrodynamic forcing increases, the blades exhibit greater motion. Greater blade motion leads to smaller relative velocities, reducing drag, and wave-energy dissipation (i.e., smaller le).

How kelp produce blade shapes suited to different flow regimes: A new wrinkle.

PubMed

Koehl, M A R; Silk, W K; Liang, H; Mahadevan, L

2008-12-01

Many species of macroalgae have flat, strap-like blades in habitats exposed to rapidly flowing water, but have wide, ruffled "undulate" blades at protected sites. We used the giant bull kelp, Nereocystis luetkeana, to investigate how these ecomorphological differences are produced. The undulate blades of N. luetkeana from sites with low flow remain spread out and flutter erratically in moving water, thereby not only enhancing interception of light, but also increasing drag. In contrast, strap-like blades of kelp from habitats with rapid flow collapse into streamlined bundles and flutter at low amplitude in flowing water, thus reducing both drag and interception of light. Transplant experiments in the field revealed that shape of the blade in N. luetkeana is a plastic trait. Laboratory experiments in which growing blades from different sites were subjected to tensile forces that mimicked the hydrodynamic drag experienced by blades in different flow regimes showed that change in shape is induced by mechanical stress. During growth experiments in the field and laboratory, we mapped the spatial distribution of growth in both undulate and strap-like blades to determine how these different morphologies were produced. The highest growth rates occur near the proximal ends of N. luetkeana blades of both morphologies, but the rates of transverse growth of narrow, strap-like blades are lower than those of wide, undulate blades. If rates of longitudinal growth at the edges of a blade exceed the rate of longitudinal growth along the midline of the blade, ruffles along the edges of the blade are produced by elastic buckling. In contrast, flat blades are produced when rates of longitudinal growth are similar across the width of a blade. Because ruffles are the result of elastic buckling, a compliant undulate N. luetkeana blade can easily be pushed into different configurations (e.g., the wavelengths of the ruffles along the edges of the blade can change, and the whole blade can twist into left- and right-handed helicoidal shapes), which may enhance movements of the blade in flowing water that reduce self-shading and increase mass exchange along blade surfaces.

Future of the Pacific: Inspiring the Next Generation of Scientists and Engineers Through Place-Based Problem-Solving Using Innovative STEM Curriculum and Technology Tools

DTIC Science & Technology

2016-03-30

lesson 8.4, " Wind Turbine Design Inquiry." 13 The goal of her project was to combine a1t and science in project-based learning. Although pmt of an...challenged to design, test, and redesign wind turbine blades, defining variables and measuring performance. Their goal was to optimize perfonnance through...hydroelectric. In each model there are more than one variable. For example, the wind farm activity enables the user to select number of turbines

Comparison of the effects of 23-gauge and 25-gauge microincision vitrectomy blade designs on incision architecture

PubMed Central

Inoue, Makoto; Abulon, Dina Joy K; Hirakata, Akito

2014-01-01

Purpose To compare the effects of different 23- and 25-gauge microincision vitrectomy trocar cannula entry systems on incision architecture. Methods We tested one ridged microvitreoretinal (MVR), one non-ridged MVR, one pointed beveled, and one round-tipped beveled blade (n=10 per blade design per incision type). Each blade’s straight and oblique incision architecture was assessed in a silicone disc simulating the sclera. Wound leakage under pressure and endoscopic observations were conducted on sclerotomy sites of isolated porcine eyes (n=4 per blade design) after simulated vitrectomy. Results Differences in blade design created distinct incision architecture. Incisions were linear with the ridged MVR blade, flattened “M-shaped” with the non-ridged MVR blade, asymmetrical chevron-shaped with the pointed beveled blade, and curved with the round-tipped beveled blade. With the exception of oblique entry incision thickness, both MVR blade designs created thinner incisions than the beveled blades at entry and exit sites. Only the ridged MVR blade created incisions with no leakage. Vitreous incarceration was observed with all trocar cannula systems. Conclusion Wound closure in porcine eyes was similar with all blades despite differences in incision architecture. Wound leakage occurred at low to moderate infusion pressures with most blades; no wound leakage was observed with ridged MVR blades. PMID:25429201

The RITA spectrometer at Risø - design considerations and recent results

NASA Astrophysics Data System (ADS)

Clausen, K. N.; McMorrow, D. F.; Lefmann, K.; Aeppli, G.; Mason, T. E.; Schröder, A.; Issikii, M.; Nohara, M.; Takagi, H.

In the new cold triple axis spectrometer RITA at Risø we have improved the front end by extensive use of state of the art optical elements and better shielding material. The analyser system is situated in one large open tank and consists of seven individually orientable PG(002) crystal analyser blades, and a 170 mm by 120 mm 2 areas sensitive micro-strip detector. In comparison to the old TAS6 spectrometer we have obtained a factor 2-5 gain in intensity on the sample, a substantially lower background, much more flexibility for optimising the instrument and the possibility to go beyond simple point-by-point inspection. The excellent performance of RITA in the standard TAS mode is exemplified by a study of the dynamics of ≈ 15 nm hematite (α-Fe 2O 3) nano-particles, and utilisation of horizontal and vertical focusing modes to study two dimensional systems is illustrated by a study of the spin fluctuations in the high Tc superconductor La 1.83Sr 0.17CuO 4.

Coastal Ohio Wind Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorsevski, Peter; Afjeh, Abdollah; Jamali, Mohsin

The Coastal Ohio Wind Project intends to address problems that impede deployment of wind turbines in the coastal and offshore regions of Northern Ohio. The project evaluates different wind turbine designs and the potential impact of offshore turbines on migratory and resident birds by developing multidisciplinary research, which involves wildlife biology, electrical and mechanical engineering, and geospatial science. Firstly, the project conducts cost and performance studies of two- and three-blade wind turbines using a turbine design suited for the Great Lakes. The numerical studies comprised an analysis and evaluation of the annual energy production of two- and three-blade wind turbinesmore » to determine the levelized cost of energy. This task also involved wind tunnel studies of model wind turbines to quantify the wake flow field of upwind and downwind wind turbine-tower arrangements. The experimental work included a study of a scaled model of an offshore wind turbine platform in a water tunnel. The levelized cost of energy work consisted of the development and application of a cost model to predict the cost of energy produced by a wind turbine system placed offshore. The analysis found that a floating two-blade wind turbine presents the most cost effective alternative for the Great Lakes. The load effects studies showed that the two-blade wind turbine model experiences less torque under all IEC Standard design load cases considered. Other load effects did not show this trend and depending on the design load cases, the two-bladed wind turbine showed higher or lower load effects. The experimental studies of the wake were conducted using smoke flow visualization and hot wire anemometry. Flow visualization studies showed that in the downwind turbine configuration the wake flow was insensitive to the presence of the blade and was very similar to that of the tower alone. On the other hand, in the upwind turbine configuration, increasing the rotor blade angle of attack reduced the wake size and enhanced the vortices in the flow downstream of the turbine-tower compared with the tower alone case. Mean and rms velocity distributions from hot wire anemometer data confirmed that in a downwind configuration, the wake of the tower dominates the flow, thus the flow fields of a tower alone and tower-turbine combinations are nearly the same. For the upwind configuration, the mean velocity shows a narrowing of the wake compared with the tower alone case. The downwind configuration wake persisted longer than that of an upwind configuration; however, it was not possible to quantify this difference because of the size limitation of the wind tunnel downstream of the test section. The water tunnel studies demonstrated that the scale model studies could be used to adequately produce accurate motions to model the motions of a wind turbine platform subject to large waves. It was found that the important factors that affect the platform is whether the platform is submerged or surface piercing. In the former, the loads on the platform will be relatively reduced whereas in the latter case, the structure pierces the wave free surface and gains stiffness and stability. The other important element that affects the movement of the platform is depth of the sea in which the wind turbine will be installed. Furthermore, the wildlife biology component evaluated migratory patterns by different monitoring systems consisting of marine radar, thermal IR camera and acoustic recorders. The types of radar used in the project are weather surveillance radar and marine radar. The weather surveillance radar (1988 Doppler), also known as Next Generation Radar (NEXRAD), provides a network of weather stations in the US. Data generated from this network were used to understand general migratory patterns, migratory stopover habitats, and other patterns caused by the effects of weather conditions. At a local scale our marine radar was used to complement the datasets from NEXRAD and to collect additional monitoring parameters such as passage rates, flight paths, flight directions, and flight altitudes of nocturnal migrating species. Our work focused on the design and development of custom built marine radar that used t-bar and parabolic dish antennas. The marine radar used in the project was Furuno (XANK250) which was coupled with a XIR3000B digitizing card from Russell Technologies for collection of the radar data. The radar data was processed by open source radR processing software using different computational techniques and methods. Additional data from thermal IR imaging cameras were collected to detect heat emitted from objects and provide information on movements of birds and bats, data which we used for different animal flight behavior analysis. Lastly, the data from the acoustic recorders were used to provide the number of bird calls for assessing patterns and peak passage rates during migration. The development of the geospatial database included collection of different data sources that are used to support offshore wind turbine development. Many different data sets were collected and organized using initial version of web-based repository software tools that can accommodate distribution of rectified pertinent data sets such as the lake depth, lake bottom engineering parameters, extent of ice, navigation pathways, wind speed, important bird habitats, fish efforts and other layers that are relevant for supporting robust offshore wind turbine developments. Additional geospatial products developed during the project included few different prototypes for offshore wind farm suitability which can involve different stakeholders and participants for solving complex planning problems and building consensus. Some of the prototypes include spatial decision support system (SDSS) for collaborative decision making, a web-based Participatory Geographic Information System (PGIS) framework for evaluating importance of different decision alternatives using different evaluation criteria, and an Android application for collection of field data using mobile and tablet devices . In summary, the simulations of two- and three-blade wind turbines suggested that two-bladed machines could produce comparable annual energy as the three-blade wind turbines but have a lighter tower top weight, which leads to lower cost of energy. In addition, the two-blade rotor configuration potentially costs 20% less than a three blade configuration that produces the same power at the same site. The cost model analysis predicted a potential cost savings of approximately 15% for offshore two-blade wind turbines. The foundation design for a wind turbine in Lake Erie is likely to be driven by ice loads based on the currently available ice data and ice mechanics models. Hence, for Lake Eire, the cost savings will be somewhat smaller than the other lakes in the Great Lakes. Considering the size of cranes and vessels currently available in the Great Lakes, the cost optimal wind turbine size should be 3 MW, not larger. The surveillance data from different monitoring systems suggested that bird and bat passage rates per hour were comparable during heavy migrations in both spring and fall seasons while passage rates were significantly correlated to wind directions and wind speeds. The altitude of migration was higher during heavy migrations and higher over water relative to over land. Notable portions of migration on some spring nights occurred parallel the shoreline, often moving perpendicular to southern winds. The birds approaching the Western basin have a higher propensity to cross than birds approaching the Central basin of Lake Erie and as such offshore turbine development might be a better option further east towards Cleveland than in the Western basin. The high stopover density was more strongly associated with migration volume the following night rather than the preceding night. The processed mean scalar wind speeds with temporal resolutions as fine as 10-minute intervals near turbine height showed that August is the month with the weakest winds while December is the month, which typically has the strongest winds. The ice data suggests that shallow western basin of Lake Erie has higher ice cover duration many times exceeding 90 days during some winters.« less

Certification of CFD heat transfer software for turbine blade analysis

NASA Technical Reports Server (NTRS)

Jordan, William A.

2004-01-01

Accurate modeling of heat transfer effects is a critical component of the Turbine Branch of the Turbomachinery and Propulsion Systems Division. Being able to adequately predict and model heat flux, coolant flows, and peak temperatures are necessary for the analysis of high pressure turbine blades. To that end, the primary goal of my internship this summer will be to certify the reliability of the CFD program GlennHT for the purpose of turbine blade heat transfer analysis. GlennHT is currently in use by the engineers in the Turbine Branch who use the FORTRAN 77 version of the code for analysis. The program, however, has been updated to a FORTRAN 90 version which is more robust than the older code. In order for the new code to be distributed for use, its reliability must first be certified. Over the course of my internship I will create and run test cases using the FORTRAN 90 version of GlennHT and compare the results to older cases which are known to be accurate, If the results of the new code match those of the sample cases then the newer version will be one step closer to certification for distribution. In order to complete these it will first be necessary to become familiar with operating a number of other programs. Among them are GridPro, which is used to create a grid mesh around a blade geometry, and FieldView, whose purpose is to graphically display the results from the GlennHT program. Once enough familiarity is established with these programs to render them useful, then the work of creating and running test scenarios will begin. The work is additionally complicated by a transition in computer hardware. Most of the working computers in the Turbine Branch are Silicon Graphics machines, which will soon be replaced by LINUX PC's. My project is one of the first to make use the new PC's. The change in system architecture however, has created several software related issues which have greatly increased the time and effort investments required by the project.Although complications with the project continue to arise, it is expected that the goal of my internship can still be achieved within the remaining time period. Critical steps have been achieved and test scenarios can now be designed and run. At the completion of my internship, the FORTRAN 90 version of GlennHT should be well on its way to certification.

Cooled snubber structure for turbine blades

DOEpatents

Mayer, Clinton A.; Campbell, Christian X.; Whalley, Andrew; Marra, John J.

2014-04-01

A turbine blade assembly in a turbine engine. The turbine blade assembly includes a turbine blade and a first snubber structure. The turbine blade includes an internal cooling passage containing cooling air. The first snubber structure extends outwardly from a sidewall of the turbine blade and includes a hollow interior portion that receives cooling air from the internal cooling passage of the turbine blade.

Materials, Manufacturing and Test Development of a Composite Fan Blade Leading Edge Subcomponent for Improved Impact Resistance

NASA Technical Reports Server (NTRS)

Handschuh, Katherine M.; Miller, Sandi G.; Sinnott, Matthew J.; Kohlman, Lee W.; Roberts, Gary D.; Pereira, J. Michael; Ruggeri, Charles R.

2014-01-01

Application of polymer matrix composite materials for jet engine fan blades is becoming attractive as an alternative to metallic blades; particularly for large engines where significant weight savings are recognized on moving to a composite structure. However, the weight benefit of the composite of is offset by a reduction of aerodynamic efficiency resulting from a necessary increase in blade thickness; relative to the titanium blades. Blade dimensions are largely driven by resistance to damage on bird strike. Further development of the composite material is necessary to allow composite blade designs to approximate the dimensions of a metallic fan blade. The reduction in thickness over the state of the art composite blades is expected to translate into structural weight reduction, improved aerodynamic efficiency, and therefore reduced fuel consumption. This paper presents test article design, subcomponent blade leading edge fabrication, test method development, and initial results from ballistic impact of a gelatin projectile on the leading edge of composite fan blades. The simplified test article geometry was developed to realistically simulate a blade leading edge while decreasing fabrication complexity. Impact data is presented on baseline composite blades and toughened blades; where a considerable improvement to impact resistance was recorded.

Materials, Manufacturing, and Test Development of a Composite Fan Blade Leading Edge Subcomponent for Improved Impact Resistance

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Handschuh, Katherine; Sinnott, Matthew J.; Kohlman, Lee W.; Roberts, Gary D.; Martin, Richard E.; Ruggeri, Charles R.; Pereira, J. Michael

2015-01-01

Application of polymer matrix composite materials for jet engine fan blades is becoming attractive as an alternative to metallic blades; particularly for large engines where significant weight savings are recognized on moving to a composite structure. However, the weight benefit of the composite is offset by a reduction of aerodynamic efficiency resulting from a necessary increase in blade thickness; relative to the titanium blades. Blade dimensions are largely driven by resistance to damage on bird strike. Further development of the composite material is necessary to allow composite blade designs to approximate the dimensions of a metallic fan blade. The reduction in thickness over the state of the art composite blades is expected to translate into structural weight reduction, improved aerodynamic efficiency, and therefore reduced fuel consumption. This paper presents test article design, subcomponent blade leading edge fabrication, test method development, and initial results from ballistic impact of a gelatin projectile on the leading edge of composite fan blades. The simplified test article geometry was developed to realistically simulate a blade leading edge while decreasing fabrication complexity. Impact data is presented on baseline composite blades and toughened blades; where a considerable improvement to impact resistance was recorded.

Optimisation of dispersion parameters of Gaussian plume model for CO₂ dispersion.

PubMed

Liu, Xiong; Godbole, Ajit; Lu, Cheng; Michal, Guillaume; Venton, Philip

2015-11-01

The carbon capture and storage (CCS) and enhanced oil recovery (EOR) projects entail the possibility of accidental release of carbon dioxide (CO2) into the atmosphere. To quantify the spread of CO2 following such release, the 'Gaussian' dispersion model is often used to estimate the resulting CO2 concentration levels in the surroundings. The Gaussian model enables quick estimates of the concentration levels. However, the traditionally recommended values of the 'dispersion parameters' in the Gaussian model may not be directly applicable to CO2 dispersion. This paper presents an optimisation technique to obtain the dispersion parameters in order to achieve a quick estimation of CO2 concentration levels in the atmosphere following CO2 blowouts. The optimised dispersion parameters enable the Gaussian model to produce quick estimates of CO2 concentration levels, precluding the necessity to set up and run much more complicated models. Computational fluid dynamics (CFD) models were employed to produce reference CO2 dispersion profiles in various atmospheric stability classes (ASC), different 'source strengths' and degrees of ground roughness. The performance of the CFD models was validated against the 'Kit Fox' field measurements, involving dispersion over a flat horizontal terrain, both with low and high roughness regions. An optimisation model employing a genetic algorithm (GA) to determine the best dispersion parameters in the Gaussian plume model was set up. Optimum values of the dispersion parameters for different ASCs that can be used in the Gaussian plume model for predicting CO2 dispersion were obtained.

Rotor blade assembly having internal loading features

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soloway, Daniel David

Rotor blade assemblies and wind turbines are provided. A rotor blade assembly includes a rotor blade having exterior surfaces defining a pressure side, a suction side, a leading edge and a trailing edge each extending between a tip and a root, the rotor blade defining a span and a chord, the exterior surfaces defining an interior of the rotor blade. The rotor blade assembly further includes a loading assembly, the loading assembly including a weight disposed within the interior and movable generally along the span of the rotor blade, the weight connected to a rotor blade component such that movementmore » of the weight towards the tip causes application of a force to the rotor blade component by the weight. Centrifugal force due to rotation of the rotor blade biases the weight towards the tip.« less

Mach number scaling of helicopter rotor blade/vortex interaction noise

NASA Technical Reports Server (NTRS)

Leighton, Kenneth P.; Harris, Wesley L.

1985-01-01

A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.

Impact absorbing blade mounts for variable pitch blades

NASA Technical Reports Server (NTRS)

Ravenhall, R.; Salemme, C. T.; Adamson, A. P. (Inventor)

1977-01-01

A variable pitch blade and blade mount are reported that are suitable for propellers, fans and the like and which have improved impact resistance. Composite fan blades and blade mounting arrangements permit the blades to pivot relative to a turbine hub about an axis generally parallel to the centerline of the engine upon impact of a large foreign object, such as a bird. Centrifugal force recovery becomes the principal energy absorbing mechanism and a blade having improved impact strength is obtained.

Blade row interaction effects on flutter and forced response

NASA Technical Reports Server (NTRS)

Buffum, Daniel H.

1993-01-01

In the flutter or forced response analysis of a turbomachine blade row, the blade row in question is commonly treated as if it is isolated from the neigboring blade rows. Disturbances created by vibrating blades are then free to propagate away from this blade row without being disturbed. In reality, neighboring blade rows will reflect some portion of this wave energy back toward the vibrating blades, causing additional unsteady forces on them. It is of fundamental importance to determine whether or not these reflected waves can have a significant effect on the aeroelastic stability or forced response of a blade row. Therefore, a procedure to calculate intra-blade-row unsteady aerodynamic interactions was developed which relies upon results available from isolated blade row unsteady aerodynamic analyses. In addition, an unsteady aerodynamic influence coefficient technique is used to obtain a model for the vibratory response in which the neighboring blade rows are also flexible. The flutter analysis shows that interaction effects can be destabilizing, and the forced response analysis shows that interaction effects can result in a significant increase in the resonant response of a blade row.

Method for maintaining a cutting blade centered in a kerf

DOEpatents

Blaedel, Kenneth L.; Davis, Pete J.; Landram, Charles S.

2002-01-01

A saw having a self-pumped hydrodynamic blade guide or bearing for retaining the saw blade in a centered position in the saw kerf (width of cut made by the saw). The hydrodynamic blade guide or bearing utilizes pockets or grooves incorporated into the sides of the blade. The saw kerf in the workpiece provides the guide or bearing stator surface. Both sides of the blade entrain cutting fluid as the blade enters the kerf in the workpiece, and the trapped fluid provides pressure between the blade and the workpiece as an inverse function of the gap between the blade surface and the workpiece surface. If the blade wanders from the center of the kerf, then one gap will increase and one gap will decrease and the consequent pressure difference between the two sides of the blade will cause the blade to re-center itself in the kerf. Saws using the hydrodynamic blade guide or bearing have particular application in slicing slabs from boules of single crystal materials, for example, as well as for cutting other difficult to saw materials such as ceramics, glass, and brittle composite materials.

Hydrodynamic blade guide

DOEpatents

Blaedel, Kenneth L.; Davis, Pete J.; Landram, Charles S.

2000-01-01

A saw having a self-pumped hydrodynamic blade guide or bearing for retaining the saw blade in a centered position in the saw kerf (width of cut made by the saw). The hydrodynamic blade guide or bearing utilizes pockets or grooves incorporated into the sides of the blade. The saw kerf in the workpiece provides the guide or bearing stator surface. Both sides of the blade entrain cutting fluid as the blade enters the kerf in the workpiece, and the trapped fluid provides pressure between the blade and the workpiece as an inverse function of the gap between the blade surface and the workpiece surface. If the blade wanders from the center of the kerf, then one gap will increase and one gap will decrease and the consequent pressure difference between the two sides of the blade will cause the blade to re-center itself in the kerf. Saws using the hydrodynamic blade guide or bearing have particular application in slicing slabs from boules of single crystal materials, for example, as well as for cutting other difficult to saw materials such as ceramics, glass, and brittle composite materials.

Novel Engineering and Fabrication Techniques Tested in Low-Noise- Research Fan Blades

NASA Technical Reports Server (NTRS)

Cunningham, Cameron C.

2003-01-01

A major source of fan noise in commercial turbofan engines is the interaction of the wake from the fan blades with the stationary vanes (stators) directly behind them. The Trailing Edge Blowing (TEB) project team at the NASA Glenn Research Center designed and fabricated new fan blades to study the effects of fan trailing edge blowing as a potential noise-reduction concept. The intent is to fill the rotor wake by supplying air to the rotor blade trailing edge at the proper conditions to minimize the wake deficit, and thus generate less noise. The TEB hardware is designed for the Active Noise Control Fan (ANCF) test rig in Glenn's Aeroacoustic Propulsion Laboratory. For this test, the air is fed from an external supply through the shaft of the rig. It is distributed to the base of each blade through an impeller, where it is forced into a plenum at the core of each blade. In actual engine configuration, air would most likely be bled from the compressor, but only at times when noise is an issue, such as takeoffs and landings. Glenn researchers designed and manufactured the blades in-house, using new techniques and concepts. The skins, which were designed for maximum strength in the directions of highest stress, were molded from multiple layers of carbon fiber. Considerable use was made of rapid prototyping techniques, such as laser sintering. The core was sintered from a lightweight polymer, and the retainer was CNC-machined (computer numerical control machined) from aluminum. All the components were joined with a cold-cure aerospace adhesive. These techniques and processes reduced the overall cost and allowed the new concept to be studied much sooner than would be possible using traditional fabrication methods. Since this test rig did not support the use of blade-monitoring techniques such as strain gauges, extensive bench testing was required to qualify the design. The blades were examined using a variety of methods including holography, pull tests (cyclic and failure), shake tests, rap tests, and nondestructive inspection. Acoustic testing of the ANCF fan using TEB has been ongoing since January of 2001. The fan has completed about 100 hr of testing with no structural, vibrational, or fatigue problems. Far-field acoustic measurements, in-duct mode measurements, precise hot wire surveys, and detailed performance measurements are providing data for evaluating the concept. The far-field noise data show that tone noise was reduced significantly with the initial ANCF TEB fan design. In addition, a significant reduction in unsteady stator loading has been measured, indicating the potential for stator broadband noise reduction. The acoustic benefits will be assessed and important design parameters identified to improve the ability to fully exploit any benefit provided by this technique. On the basis of the success of trailing edge blowing, Glenn plans to continue this research with a higher speed, higher pressure ratio fan operating in an acoustic wind tunnel to simulate flight conditions.

Effect of linear and non-linear blade modelling techniques on simulated fatigue and extreme loads using Bladed

NASA Astrophysics Data System (ADS)

Beardsell, Alec; Collier, William; Han, Tao

2016-09-01

There is a trend in the wind industry towards ever larger and more flexible turbine blades. Blade tip deflections in modern blades now commonly exceed 10% of blade length. Historically, the dynamic response of wind turbine blades has been analysed using linear models of blade deflection which include the assumption of small deflections. For modern flexible blades, this assumption is becoming less valid. In order to continue to simulate dynamic turbine performance accurately, routine use of non-linear models of blade deflection may be required. This can be achieved by representing the blade as a connected series of individual flexible linear bodies - referred to in this paper as the multi-part approach. In this paper, Bladed is used to compare load predictions using single-part and multi-part blade models for several turbines. The study examines the impact on fatigue and extreme loads and blade deflection through reduced sets of load calculations based on IEC 61400-1 ed. 3. Damage equivalent load changes of up to 16% and extreme load changes of up to 29% are observed at some turbine load locations. It is found that there is no general pattern in the loading differences observed between single-part and multi-part blade models. Rather, changes in fatigue and extreme loads with a multi-part blade model depend on the characteristics of the individual turbine and blade. Key underlying causes of damage equivalent load change are identified as differences in edgewise- torsional coupling between the multi-part and single-part models, and increased edgewise rotor mode damping in the multi-part model. Similarly, a causal link is identified between torsional blade dynamics and changes in ultimate load results.

Towards Personalising Learning in School Science: Making This Learning More Relevant

ERIC Educational Resources Information Center

Prain, Vaughan; Waldrip, Bruce; Sbaglia, Rob; Lovejoy, Val

2017-01-01

In this paper, we report on a case study of how three teachers personalised learning in science through supporting a group of Year 8 students to engage in individual inquiry projects. The case study demonstrated how heavily transmissive teaching can be avoided by restructuring classes to optimise student group and individual work and timely…

Does the Miller blade truly provide a better laryngoscopic view and intubating conditions than the Macintosh blade in small children?

PubMed

Varghese, Elsa; Kundu, Ratul

2014-08-01

Both Miller and Macintosh blades are widely used for laryngoscopy in small children, though the Miller blade is more commonly recommended in pediatric anesthetic literature. The aim of this study was to compare laryngoscopic views and ease and success of intubation with Macintosh and Miller blades in small children under general anesthesia. One hundred and twenty children aged 1-24 months were randomized for laryngoscopy to be performed in a crossover manner with either the Miller or the Macintosh blade first, following induction of anesthesia and neuromuscular blockade. The tips of both the blades were placed at the vallecula. Intubation was performed following the second laryngoscopy. The glottic views with and without external laryngeal maneuver (ELM) and ease of intubation were observed. Similar glottic views with both blades were observed in 52/120 (43%) children, a better view observed with the Miller blade in 35/120 (29%) children, and with the Macintosh blade in 33/120 (28%). Laryngoscopy was easy in 65/120 (54%) children with both the blades. Restricted laryngoscopy was noted in 55 children: in 27 children with both the blades, 15 with Miller, and 13 with Macintosh blade. Laryngoscopic view improved following ELM with both the blades. In children aged 1-24 months, the Miller and the Macintosh blades provide similar laryngoscopic views and intubating conditions. When a restricted view is obtained, a change of blade may provide a better view. Placing the tip of the Miller blade in the vallecula provides satisfactory intubating conditions in this age group. © 2014 John Wiley & Sons Ltd.

Definition of a 5MW/61.5m wind turbine blade reference model.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Resor, Brian Ray

2013-04-01

A basic structural concept of the blade design that is associated with the frequently utilized %E2%80%9CNREL offshore 5-MW baseline wind turbine%E2%80%9D is needed for studies involving blade structural design and blade structural design tools. The blade structural design documented in this report represents a concept that meets basic design criteria set forth by IEC standards for the onshore turbine. The design documented in this report is not a fully vetted blade design which is ready for manufacture. The intent of the structural concept described by this report is to provide a good starting point for more detailed and targeted investigationsmore » such as blade design optimization, blade design tool verification, blade materials and structures investigations, and blade design standards evaluation. This report documents the information used to create the current model as well as the analyses used to verify that the blade structural performance meets reasonable blade design criteria.« less

Cooling of Gas Turbines. 2; Effectiveness of Rim Cooling of Blades

NASA Technical Reports Server (NTRS)

Wolfenstein, Lincoln; Meyer, Gene L.; McCarthy, John S.

1947-01-01

An analysis is presented of rim cooling of gas-turbine blades; that is, reducing the temperature at the base of the blade (wheel rim), which cools the blade by conduction alone. Formulas for temperature and stress distributions along the blade are derived and, by the use of experimental stress-rupture data for a typical blade alloy, a relation is established between blade life (time for rupture), operating speed, and amount of rim cooling for several gas temperatures. The effect of blade parameter combining the effects of blade dimensions, blade thermal conductivity, and heat-transfer coefficient is determined. The effect of radiation on the results is approximated. The gas temperatures ranged from 1300F to 1900F and the rim temperature, from 0F to 1000F below the gas temperature. This report is concerned only with blades of uniform cross section, but the conclusions drawn are generally applicable to most modern turbine blades. For a typical rim-cooled blade, gas temperature increases are limited to about 200F for 500F of cooling of the blade base below gas temperature, and additional cooling brings progressively smaller increases. In order to obtain large increases in thermal conductivity or very large decreases in heat-transfer coefficient or blade length or necessary. The increases in gas temperature allowable with rim cooling are particularly small for turbines of large dimensions and high specific mass flows. For a given effective gas temperature, substantial increases in blade life, however, are possible with relatively small amounts of rim cooling.

Computing Shapes Of Cascade Diffuser Blades

NASA Technical Reports Server (NTRS)

Tran, Ken; Prueger, George H.

1993-01-01

Computer program generates sizes and shapes of cascade-type blades for use in axial or radial turbomachine diffusers. Generates shapes of blades rapidly, incorporating extensive cascade data to determine optimum incidence and deviation angle for blade design based on 65-series data base of National Advisory Commission for Aeronautics and Astronautics (NACA). Allows great variability in blade profile through input variables. Also provides for design of three-dimensional blades by allowing variable blade stacking. Enables designer to obtain computed blade-geometry data in various forms: as input for blade-loading analysis; as input for quasi-three-dimensional analysis of flow; or as points for transfer to computer-aided design.

Steady State Structural Analysis of High Pressure Gas Turbine Blade using Finite Element Analysis

NASA Astrophysics Data System (ADS)

Mazarbhuiya, Hussain Mahamed Sahed Mostafa; Murari Pandey, Krishna

2017-08-01

In gas turbines the major portion of performance dependency lies upon turbine blade design. Turbine blades experience very high centrifugal, axial and tangential force during power generation. While withstanding these forces blades undergo elongation. Different methods have proposed for better enhancement of the mechanical properties of blade to withstand in extreme condition. Present paper describes the stress and elongation for blades having properties of different materials. Steady state structural analysis have performed in the present work for different materials (In 625, In 718, In 738, In 738 LC, MAR M246, Ni-Cr, Ti-alloy, Ti-Al, Ti-T6, U500). Remarkable finding is that the root of the blade is subjected to maximum stress for all blade materials and the blade made of MAR M246 has less stress and deformation among all other blade materials which can be selected as a suitable material for gas turbine blade.

Helicopter far-field acoustic levels as a function of reduced rotor speeds

NASA Technical Reports Server (NTRS)

Mueller, Arnold W.; Lemasurier, Philip; Smith, Charles D.

1990-01-01

This paper will present far-field measured noise levels relative to tests conducted with a model S-76A helicopter. The project was designed to provide supplemental experimental flight data which may be used to further study reduced helicopter rotor speeds (and thus, advancing blade-tip Mach number) effects on far-field acoustic levels. The aircraft was flown in straight and level flight while operating with both the rotor speed and flight speed as test variables. The rotor speed was varied over the range of 107 percent of the main-rotor speed (NR) to 90 percent NR and with the forward flight speed varied over the range of 155 to 35 knots indicated air speed. These conditions produced a wide range of advancing blade-tip Mach numbers to which the noise data are related.

Structural Load Alleviation Applied to Next Generation Aircraft and Wind Turbines

NASA Technical Reports Server (NTRS)

Frost, Susan

2011-01-01

Reducing the environmental impact of aviation is a goal of the Subsonic Fixed Wing Project under the Fundamental Aeronautics Program of NASAs Aeronautics Research Mission Directorate. Environmental impact of aviation is being addressed by novel aircraft configurations and materials that reduce aircraft weight and increase aerodynamic efficiency. NASA is developing tools to address the challenges of increased airframe flexibility created by wings constructed with reduced structural material and novel light-weight materials. This talk will present a framework and demonstration of a flight control system using optimal control allocation with structural load feedback and constraints to achieve safe aircraft operation. As wind turbines age, they become susceptible to many forms of blade degradation. Results will be presented on work in progress that uses adaptive contingency control for load mitigation in a wind turbine simulation with blade damage progression modeled.

Theoretical Evaluation of Methods of Cooling the Blades of Gas Turbines

NASA Technical Reports Server (NTRS)

Sanders, J. C.; Mendelson, Alexander

1947-01-01

A study was made of heat transfer in turbine blades and the effects on blade temperature of cooling the blade root and tip, changing the dimensions of the blades, raising the cycle temperatures, insulating with ceramics, and cooling by circulation of air or water through hollow blades.

Ceramic blade attachment system

DOEpatents

Boyd, Gary L.

1995-01-01

A retainer ring is arranged to mount turbine blades to a turbine disk so that aerodynamic forces produced by a gas turbine engine are transferred from the turbine blades to the turbine disk to cause the turbine blades and turbine disk to rotate, but so that centrifugal forces of the turbine blades resulting from the rotation of the turbine blades and turbine disk are not transferred from the turbine blades to the turbine disk.

Experimental Investigation of the Vibration Characteristics of Four Designs of Turbine Blades and of the Effect Produced by Varying the Axial Spacing Between Nozzle Blades and Turbine Blades.

NASA Technical Reports Server (NTRS)

Morgan, W C; Morse, C R

1952-01-01

An investigation was made to determine the effects of varying the spacing between the nozzle blades and the turbine blades of a turbo-jet engine on turbine-blade vibration for four turbine-blade designs of different degrees of stiffness. In general, there was a tendency toward increase in occurrence of vibration with decrease in spacing. The effect was most evident in the case of the turbine blades that had greater stiffness.

Low-cost composite blades for the Mod-0A wind turbines

NASA Technical Reports Server (NTRS)

Weingart, O.

1982-01-01

Low cost approaches to the design and fabrication of blades for a two-bladed 200 kW wind turbine were identified and the applicability of the techniques to larger and smaller blades was assessed. Blade tooling was designed and fabricated. Two complete blades and a partial blade for tool tryout were built. The patented TFT process was used to wind the entire blade. This process allows rapid winding of an axially oriented composite onto a tapered mandrel, with tapered wall thickness. The blade consists of a TFT glass-epoxy airfoil structure filament wound onto a steel root end fitting. The fitting is, in turn, bolted to a conical steel adapter section to provide for mounting attachment to the hub. Structural analysis, blade properties, and cost and weight analysis are described.

Experimental Investigation of Inter-Blade Vortices in a Model Francis Turbine

NASA Astrophysics Data System (ADS)

LIU, Demin; LIU, Xiaobing; ZHAO, Yongzhi

2017-07-01

The inter-blade vortex in a Francis turbine becomes one of the main hydraulic factors that are likely to cause blade erosion at deep part load operating conditions. However, the causes and the mechanism of inter-blade vortex are still under investigation according to present researches. Thus the causes of inter-blade vortex and the effect of different hydraulic parameters on the inter-blade vortex are investigated experimentally. The whole life cycle of the inter-blade vortex is observed by a high speed camera. The test results illustrate the whole life cycle of the inter-blade vortex from generation to separation and even to fading. It is observed that the inter-blade vortex becomes stronger with the decreasing of flow and head, which leads to pressure fluctuation. Meanwhile, the pressure fluctuations in the vane-less area and the draft tube section become stronger when inter-blade vortices exist in the blade channel. The turbine will be damaged if operating in the inter-blade vortex zone, so its operating range must be far away from that zone. This paper reveals the main cause of the inter-blade vortex which is the larger incidence angle between the inflow angle and the blade angle on the leading edge of the runner at deep part load operating conditions.

Ice friction of flared ice hockey skate blades.

PubMed

Federolf, Peter A; Mills, Robert; Nigg, Benno

2008-09-01

In ice hockey, skating performance depends on the skill and physical conditioning of the players and on the characteristics of their equipment. CT Edge have recently designed a new skate blade that angles outward near the bottom of the blade. The objective of this study was to compare the frictional characteristics of three CT Edge blades (with blade angles of 4 degrees, 60, and 8 degrees, respectively) with the frictional characteristics of a standard skate blade. The friction coefficients of the blades were determined by measuring the deceleration of an aluminium test sled equipped with three test blades. The measurements were conducted with an initial sled speed of 1.8 m s(-1) and with a load of 53 kg on each blade. The friction coefficient of the standard blades was 0.0071 (s = 0.0005). For the CT Edge blades with blade angles of 4 degrees, 6 degrees, and 8 degrees, friction coefficients were lower by about 13%, 21%, and 22%, respectively. Furthermore, the friction coefficients decreased with increasing load. The results of this study show that widely accepted paradigms such as "thinner blades cause less friction" need to be revisited. New blade designs might also be able to reduce friction in speed skating, figure skating, bobsledding, and luge.

Aeroelastic stability and response of rotating structures

NASA Technical Reports Server (NTRS)

Keith, Theo G., Jr.

1993-01-01

A summary of the work performed during the progress period is presented. Analysis methods for predicting loads and instabilities of wind turbines were developed. Three new areas of research to aid the Advanced Turboprop Project (ATP) were initiated and developed. These three areas of research are aeroelastic analysis methods for cascades including blade and disk flexibility; stall flutter analysis; and computational aeroelasticity.

77 FR 58369 - York Haven Power Company, LLC; Notice of Application Tendered for Filing With the Commission and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-20

... end of the headrace where it runs diagonally across the main channel of the river approximately 4,970... not used under normal run-of-river operation. The normal water surface elevation of the project...-3 are vertical-shaft, fixed-blade, Kaplan turbines; unit 4 is a vertical-shaft, manually adjustable...

78 FR 26345 - York Haven Power Company, LLC; Notice of Application Accepted for Filing, Soliciting Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-06

... it runs diagonally across the main channel of the river approximately 4,970 feet to the west shore of... normal run-of-river operation. The normal water surface elevation of the project impoundment is 276.5... appurtenant equipment. The hydraulic equipment for units 1-3 are vertical-shaft, fixed-blade, Kaplan turbines...

The NASA Environmentally Responsible Aviation Project/General Electric Open Rotor Test Campaign

NASA Technical Reports Server (NTRS)

Van Zante, Dale

2013-01-01

The Open Rotor is a modern version of the UnDucted Fan (UDF) that was flight tested in the late 1980's through a partnership between NASA and General Electric (GE). Tests were conducted in the 9'x15' Low Speed Wind Tunnel and the 8'x6' Supersonic Wind Tunnel starting in late 2009 and completed in early 2012. Aerodynamic and acoustic data were obtained for takeoff, approach and cruise simulations. GE was the primary partner, but other organizations were involved such as Boeing and Airbus who provided additional hardware for fuselage simulations. This test campaign provided the acoustic and performance characteristics for modern open rotor blades designs." NASA and GE conducted joint systems analysis to evaluate how well new blade designs would perform on a B737 class aircraft, and compared the results to an advanced higher bypass ratio turbofan." Acoustic shielding experiments were performed at NASA GRC and Boeing LSAF facilities to provide data for noise estimates of unconventional aircraft configurations with Open Rotor propulsion systems." The work was sponsored by NASA's aeronautics programs, including the Subsonic Fixed Wing (SFW) and the Environmentally Responsible Aviation (ERA) projects."

Numerical simulation of blade-passage noise.

PubMed

Yauwenas, Yendrew; Zajamšek, Branko; Reizes, John; Timchenko, Victoria; Doolan, Con J

2017-09-01

Numerical simulations are used to investigate the noise generated by the passage of a rotor blade past a fixed object (the blade-passage effects), which was studied by simulating a three-bladed rotor that is supported by a vertical cylindrical tower. To isolate the blade-passage effects, no incoming wind was introduced in the simulation. The symmetric blade was set to zero pitch angle relative to the plane of rotation and two blade-tower distances were investigated. The sliding mesh method was used to simulate the rotation of the blades and Curle's acoustic analogy was used to predict the noise generated from the simulated flow data. Intense force fluctuations occur during the interaction on both the tower and the passing blade, and these are the primary sources of blade-passage noise. The contribution of the force fluctuations on the support tower to blade-passage noise, which previously had been ignored, was revealed to be more significant than that of the blades. The numerical model successfully predicts the noise spectra, which are validated by the very good agreement with experimental measurements. The simulations provide a framework to better understand blade-tower interaction noise in various applications.

Three-dimensional flow in radial turbomachinery and its impact on design

NASA Technical Reports Server (NTRS)

Tan, Choon S.; Hawthorne, William

1993-01-01

In the two papers on the 'Theory of Blade Design for Large Deflections' published in 1984, a new inverse design technique was presented for designing the shape of turbomachinery blades in three-dimensional flow. The technique involves the determination of the blade profile from the specification of a distribution of the product of the radius and the pitched averaged tangential velocity (i.e., r bar-V(sub theta), the mean swirl schedule) within the bladed region. This is in contrast to the conventional inverse design technique for turbomachinery blading in two dimensional flow in which the blade surface pressure or velocity distribution is specified and the blade profile determined as a result; this is feasible in two-dimensional flow because the streamlines along the blade surfaces are known a priori. However, in three-dimensional flow, the stream surface is free to deform within the blade passage so that the streamlines on the blade surfaces are not known a priori; thus it is difficult and not so useful to prescribe the blade surface pressure or velocity distribution and determine the resulting blade profile. It therefore seems logical to prescribe the swirl schedule within the bladed region for designing a turbomachinery blade profile in three-dimensional flow. Furthermore, specifying r bar-V(sub theta) has the following advantages: (1) it is related to the circulation around the blade (i.e., it is an aerodynamic quantity); (2) the work done or extracted is approximately proportional to the overall change in r bar-V(sub theta) across a given blade row (Euler turbine equation); and (3) the rate of change of r bar-V(sub theta) along the mean streamline at the blade is related to the pressure jump across the blade and therefore the blade loading. Since the publications of those two papers, the technique has been applied to the design of a low speed as well as a high speed radial inflow turbine (for turbocharger applications) both of which showed definite improvements in performance over that of wheels of conventional designs, the design study of a high pressure ratio radial inflow turbine with and without splitter blades.

Use of Blade Lean in Turbomachinery Redesign

NASA Technical Reports Server (NTRS)

Moore, John; Moore, Joan G.; Lupi, Alex

1993-01-01

Blade lean is used to improve the uniformity of exit flow distributions from turbomachinery blading. In turbines, it has been used to control secondary flows by tailoring blade turning to reduce flow overturning and underturning and to create more uniform loss distributions from hub to shroud. In the present study, the Pump Consortium centrifugal impeller has been redesigned using blade lean. The flow at the exit of the baseline impeller had large blade-to-blade variations, creating a highly unsteady flow for the downstream diffuser. Blade lean is used to redesign the flow to move the high loss fluid from the suction side to the hub, significantly reducing blade-toblade variations at the exit.

The Cardiff paediatric laryngoscope blade: a comparison with the Miller size 1 and Macintosh size 2 laryngoscope blades.

PubMed

Jones, R M; Jones, P L; Gildersleve, C D; Hall, J E; Harding, L J E; Chawathe, M S

2004-10-01

The Cardiff paediatric laryngoscope blade is a single blade that has been designed for use in children from birth to adolescence. This open, randomised, crossover study compared the Cardiff blade with the straight, size 1, Miller laryngoscope blade in 39 infants under 1 years of age and the curved, size 2, Macintosh blade in 39 children aged 1-16 years. The same laryngoscopic view was obtained with the Cardiff and Miller blades in 26 patients; the view was better with the Cardiff blade in seven patients and better with the Miller blade in six (median (IQR [range]) grade of laryngoscopy 1 (1-2 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.405). The Cardiff blade was faster at gaining a view than the Miller blade (mean (SD) time 8.5 (2.9) s vs. 10.2 (3.5) s, respectively; 95% CI for difference -2.8 to -0.4; p = 0.009). The Cardiff and Macintosh blades produced the same view in 32 patients; the view was better with the Cardiff blade in seven patients (median (IQR [range]) grade of laryngoscopy 1 (1-1 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.008). There was no difference in time to gain these views: mean (SD) 8.7 (3.0) s vs. 9.3 (2.7) s, respectively (95% CI for difference -1.58 to 0.40; p = 0.237). The Cardiff paediatric laryngoscope blade compares favourably with these two established laryngoscope blades in children.

Aerodynamics and Optimal Design of Biplane Wind Turbine Blades

NASA Astrophysics Data System (ADS)

Chiu, Phillip

In order to improve energy capture and reduce the cost of wind energy, in the past few decades wind turbines have grown significantly larger. As their blades get longer, the design of the inboard region (near the blade root) becomes a trade-off between competing structural and aerodynamic requirements. State-of-the-art blades require thick airfoils near the root to efficiently support large loads inboard, but those thick airfoils have inherently poor aerodynamic performance. New designs are required to circumvent this design compromise. One such design is the "biplane blade", in which the thick airfoils in the inboard region are replaced with thinner airfoils in a biplane configuration. This design was shown previously to have significantly increased structural performance over conventional blades. In addition, the biplane airfoils can provide increased lift and aerodynamic efficiency compared to thick monoplane inboard airfoils, indicating a potential for increased power extraction. This work investigates the fundamental aerodynamic aspects, aerodynamic design and performance, and optimal structural design of the biplane blade. First, the two-dimensional aerodynamics of biplanes with relatively thick airfoils are investigated, showing unique phenomena which arise as a result of airfoil thickness. Next, the aerodynamic design of the full biplane blade is considered. Two biplane blades are designed for optimal aerodynamic loading, and their aerodynamic performance quantified. Considering blades with practical chord distributions and including the drag of the mid-blade joint, it is shown that biplane blades have comparable power output to conventional monoplane designs. The results of this analysis also show that the biplane blades can be designed with significantly less chord than conventional designs, a characteristic which enables larger blade designs. The aerodynamic loads on the biplane blades are shown to be increased in gust conditions and decreased under extreme conditions. Finally, considering these aerodynamic loads, the blade mass reductions achievable by biplane blades are quantified. The internal structure of the biplane blades are designed using a multi-disciplinary optimization which seeks to minimize mass, subject to constraints which represent realistic design requirements. Using this approach, it is shown that biplane blades can be built more than 45% lighter than a similarly-optimized conventional blade; the reasons for these mass reductions are examined in detail. As blade length is increased, these mass reductions are shown to be even more significant. These large mass reductions are indicative of significant cost of electricity reductions from rotors fitted with biplane blades. Taken together, these results show that biplane blades are a concept which can enable the next generation of larger wind turbine rotors.

Metal spar/superhybrid shell composite fan blades. [for application to turbofan engins

NASA Technical Reports Server (NTRS)

Salemme, C. T.; Murphy, G. C.

1979-01-01

The use of superhybrid materials in the manufacture and testing of large fan blades is analyzed. The FOD resistance of large metal spar/superhybrid fan blades is investigated. The technical effort reported was comprised of: (1) preliminary blade design; (2) detailed analysis of two selected superhybrid blade designs; (3) manufacture of two process evaluation blades and destructive evaluation; and (4) manufacture and whirligig testing of six prototype superhybrid blades.

Ceramic blade attachment system

DOEpatents

Boyd, G.L.

1995-04-11

A retainer ring is arranged to mount turbine blades to a turbine disk so that aerodynamic forces produced by a gas turbine engine are transferred from the turbine blades to the turbine disk to cause the turbine blades and turbine disk to rotate, but so that centrifugal forces of the turbine blades resulting from the rotation of the turbine blades and turbine disk are not transferred from the turbine blades to the turbine disk. 6 figures.

Evaluation of Rotor Structural and Aerodynamic Loads using Measured Blade Properties

NASA Technical Reports Server (NTRS)

Jung, Sung N.; You, Young-Hyun; Lau, Benton H.; Johnson, Wayne; Lim, Joon W.

2012-01-01

The structural properties of Higher harmonic Aeroacoustic Rotor Test (HART I) blades have been measured using the original set of blades tested in the wind tunnel in 1994. A comprehensive rotor dynamics analysis is performed to address the effect of the measured blade properties on airloads, blade motions, and structural loads of the rotor. The measurements include bending and torsion stiffness, geometric offsets, and mass and inertia properties of the blade. The measured properties are correlated against the estimated values obtained initially by the manufacturer of the blades. The previously estimated blade properties showed consistently higher stiffnesses, up to 30% for the flap bending in the blade inboard root section. The measured offset between the center of gravity and the elastic axis is larger by about 5% chord length, as compared with the estimated value. The comprehensive rotor dynamics analysis was carried out using the measured blade property set for HART I rotor with and without HHC (Higher Harmonic Control) pitch inputs. A significant improvement on blade motions and structural loads is obtained with the measured blade properties.

Laryngoscope plastic blades in scheduled general anesthesia patients: a comparative randomized study.

PubMed

Galinski, Michel; Catineau, Jean; Rayeh, Fatima; Muret, Jane; Ciebiera, Jean-Pierre; Plantevin, Frédéric; Foucrier, Arnaud; Tual, Loic; Combes, Xavier; Adnet, Frédéric

2011-03-01

To compare two brands of disposable plastic laryngoscope blades, Vital View plastic blades and Heine XP plastic blades, with the reusable Heine Classic+ Macintosh metal blades. Prospective randomized, controlled, single-blinded study. Operating room of a university-affiliated hospital. 519 patients without criteria for predicted difficult intubation, undergoing scheduled surgery during general anesthesia. Patients were randomized to three groups according to laryngoscope blade brand. Difficult tracheal intubation was evaluated by the Intubation Difficulty Scale (IDS) (IDS > 5 = procedure involving moderate to major difficulty). The percentage of intubations with an IDS > 5 was 3.1% in Group M (metal blade group), 5.1% in Group V (Vital View plastic blade group), and 10.0% in Group H (Heine plastic blade group). A significant difference was noted between Groups M and H (P = 0.02) but not between Groups M and V. Intubation may be more challenging when using Heine XP plastic blades but no significant difference exists between Vital-View plastic blades and Heine Classic+ metal blades. Copyright © 2011 Elsevier Inc. All rights reserved.

Choosing the appropriate forecasting model for predictive parameter control.

PubMed

Aleti, Aldeida; Moser, Irene; Meedeniya, Indika; Grunske, Lars

2014-01-01

All commonly used stochastic optimisation algorithms have to be parameterised to perform effectively. Adaptive parameter control (APC) is an effective method used for this purpose. APC repeatedly adjusts parameter values during the optimisation process for optimal algorithm performance. The assignment of parameter values for a given iteration is based on previously measured performance. In recent research, time series prediction has been proposed as a method of projecting the probabilities to use for parameter value selection. In this work, we examine the suitability of a variety of prediction methods for the projection of future parameter performance based on previous data. All considered prediction methods have assumptions the time series data has to conform to for the prediction method to provide accurate projections. Looking specifically at parameters of evolutionary algorithms (EAs), we find that all standard EA parameters with the exception of population size conform largely to the assumptions made by the considered prediction methods. Evaluating the performance of these prediction methods, we find that linear regression provides the best results by a very small and statistically insignificant margin. Regardless of the prediction method, predictive parameter control outperforms state of the art parameter control methods when the performance data adheres to the assumptions made by the prediction method. When a parameter's performance data does not adhere to the assumptions made by the forecasting method, the use of prediction does not have a notable adverse impact on the algorithm's performance.

Jet Flap Stator Blade Test in the High Reaction Turbine Blade Cascade Tunnel

NASA Image and Video Library

1970-03-21

A researcher examines the setup of a jet flap blade in the High Reaction Turbine Blade Cascade Tunnel at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Lewis researchers were seeking ways to increase turbine blade loading on aircraft engines in an effort to reduce the overall size and weight of engines. The ability of each blade to handle higher loads meant that fewer stages and fewer blades were required. This study analyzed the performance of a turbine blade using a jet flap and high loading. A jet of air was injected into the main stream from the pressure surface near the trailing edge. The jet formed an aerodynamic flap which deflected the flow and changed the circulation around the blade and thus increased the blade loading. The air jet also reduced boundary layer thickness. The jet-flap blade design was appealing because the cooling air may also be used for the jet. The performance was studied in a two-dimensional cascade including six blades. The researcher is checking the jet flat cascade with an exit survey probe. The probe measured the differential pressure that was proportional to the flow angle. The blades were tested over a range of velocity ratios and three jet flow conditions. Increased jet flow improved the turning and decreased both the weight flow and the blade loading. However, high blade loadings were obtained at all jet flow conditions.

Accurate and automatic extrinsic calibration method for blade measurement system integrated by different optical sensors

NASA Astrophysics Data System (ADS)

He, Wantao; Li, Zhongwei; Zhong, Kai; Shi, Yusheng; Zhao, Can; Cheng, Xu

2014-11-01

Fast and precise 3D inspection system is in great demand in modern manufacturing processes. At present, the available sensors have their own pros and cons, and hardly exist an omnipotent sensor to handle the complex inspection task in an accurate and effective way. The prevailing solution is integrating multiple sensors and taking advantages of their strengths. For obtaining a holistic 3D profile, the data from different sensors should be registrated into a coherent coordinate system. However, some complex shape objects own thin wall feather such as blades, the ICP registration method would become unstable. Therefore, it is very important to calibrate the extrinsic parameters of each sensor in the integrated measurement system. This paper proposed an accurate and automatic extrinsic parameter calibration method for blade measurement system integrated by different optical sensors. In this system, fringe projection sensor (FPS) and conoscopic holography sensor (CHS) is integrated into a multi-axis motion platform, and the sensors can be optimally move to any desired position at the object's surface. In order to simple the calibration process, a special calibration artifact is designed according to the characteristics of the two sensors. An automatic registration procedure based on correlation and segmentation is used to realize the artifact datasets obtaining by FPS and CHS rough alignment without any manual operation and data pro-processing, and then the Generalized Gauss-Markoff model is used to estimate the optimization transformation parameters. The experiments show the measurement result of a blade, where several sampled patches are merged into one point cloud, and it verifies the performance of the proposed method.

Modeling Smart Structure of Wind Turbine Blade

NASA Astrophysics Data System (ADS)

Qiao, Yin-hu; Han, Jiang; Zhang, Chun-yan; Chen, Jie-ping

2012-06-01

With the increasing size of wind turbine blades, the need for more sophisticated load control techniques has induced the interest for aerodynamic control systems with build-in intelligence on the blades. The paper aims to provide a way for modeling the adaptive wind turbine blades and analyze its ability for vibration suppress. It consists of the modeling of the adaptive wind turbine blades with the wire of piezoelectric material embedded in blade matrix, and smart sandwich structure of wind turbine blade. By using this model, an active vibration method which effectively suppresses the vibrations of the smart blade is designed.

Study on Determination Method of Fatigue Testing Load for Wind Turbine Blade

NASA Astrophysics Data System (ADS)

Liao, Gaohua; Wu, Jianzhong

2017-07-01

In this paper, the load calculation method of the fatigue test was studied for the wind turbine blade under uniaxial loading. The characteristics of wind load and blade equivalent load were analyzed. The fatigue property and damage theory of blade material were studied. The fatigue load for 2MW blade was calculated by Bladed, and the stress calculated by ANSYS. Goodman modified exponential function S-N curve and linear cumulative damage rule were used to calculate the fatigue load of wind turbine blades. It lays the foundation for the design and experiment of wind turbine blade fatigue loading system.

Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

NASA Technical Reports Server (NTRS)

Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

2012-01-01

Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

Structural Testing of the Blade Reliability Collaborative Effect of Defect Wind Turbine Blades

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desmond, M.; Hughes, S.; Paquette, J.

Two 8.3-meter (m) wind turbine blades intentionally constructed with manufacturing flaws were tested to failure at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) south of Boulder, Colorado. Two blades were tested; one blade was manufactured with a fiberglass spar cap and the second blade was manufactured with a carbon fiber spar cap. Test loading primarily consisted of flap fatigue loading of the blades, with one quasi-static ultimate load case applied to the carbon fiber spar cap blade. Results of the test program were intended to provide the full-scale test data needed for validation ofmore » model and coupon test results of the effect of defects in wind turbine blade composite materials. Testing was part of the Blade Reliability Collaborative (BRC) led by Sandia National Laboratories (SNL). The BRC seeks to develop a deeper understanding of the causes of unexpected blade failures (Paquette 2012), and to develop methods to enable blades to survive to their expected operational lifetime. Recent work in the BRC includes examining and characterizing flaws and defects known to exist in wind turbine blades from manufacturing processes (Riddle et al. 2011). Recent results from reliability databases show that wind turbine rotor blades continue to be a leading contributor to turbine downtime (Paquette 2012).« less

78 FR 69987 - Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters (Type Certificate...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

... to require recurring checks of the Blade Inspection Method (BIM) indicator on each blade to determine whether the BIM indicator is signifying that the blade pressure may have been compromised by a blade crack... check procedures for BIM blades installed on the Model S-64E and S-64F helicopters. Several blade spars...

Wind blade spar cap and method of making

DOEpatents

Mohamed, Mansour H [Raleigh, NC

2008-05-27

A wind blade spar cap for strengthening a wind blade including an integral, unitary three-dimensional woven material having a first end and a second end, corresponding to a root end of the blade and a tip end of the blade, wherein the material tapers in width from the first to the second end while maintaining a constant thickness and decreasing weight therebetween, the cap being capable of being affixed to the blade for providing increased strength with controlled variation in weight from the root end to the tip end based upon the tapered width of the material thereof. The present inventions also include the method of making the wind blade spar cap and a wind blade including the wind blade spar cap.

Reduction of turbomachinery noise

NASA Technical Reports Server (NTRS)

Waitz, Ian A. (Inventor); Hayden, Belva J. (Inventor); Ingard, K. Uno (Inventor); Brookfield, John M. (Inventor); Sell, Julian (Inventor)

1999-01-01

In the invention, propagating broad band and tonal acoustic components of noise characteristic of interaction of a turbomachine blade wake, produced by a turbomachine blade as the blade rotates, with a turbomachine component downstream of the rotating blade, are reduced. This is accomplished by injection of fluid into the blade wake through a port in the rotor blade. The mass flow rate of the fluid injected into the blade wake is selected to reduce the momentum deficit of the wake to correspondingly increase the time-mean velocity of the wake and decrease the turbulent velocity fluctuations of the wake. With this fluid injection, reduction of both propagating broad band and tonal acoustic components of noise produced by interaction of the blade wake with a turbomachine component downstream of the rotating blade is achieved. In a further noise reduction technique, boundary layer fluid is suctioned into the turbomachine blade through a suction port on the side of the blade that is characterized as the relatively low-pressure blade side. As with the fluid injection technique, the mass flow rate of the fluid suctioned into the blade is here selected to reduce the momentum deficit of the wake to correspondingly increase the time-mean velocity of the wake and decrease the turbulent velocity fluctuations of the wake; reduction of both propagating broad band and tonal acoustic components of noise produced by interaction of the blade wake with a turbomachine component downstream of the rotating blade is achieved with this suction technique. Blowing and suction techniques are also provided in the invention for reducing noise associated with the wake produced by fluid flow around a stationary blade upstream of a rotating turbomachine.

On the transonic aerodynamics of a compressor blade row

NASA Technical Reports Server (NTRS)

Erickson, J. C., Jr.; Lordi, J. A.; Rae, W. J.

1971-01-01

Linearized analyses have been carried out for the induced velocity and pressure fields within a compressor blade row operating in an infinite annulus at transonic Mach numbers of the flow relative to the blades. In addition, the relationship between the induced velocity and the shape of the mean blade surface has been determined. A computational scheme has been developed for evaluating the blade mean surface ordinates and surface pressure distributions. The separation of the effects of a specified blade thickness distribution from the effects of a specified distribution of the blade lift has been established. In this way, blade mean surface shapes that are necessary for the blades to be locally nonlifting have been computed and are presented for two examples of blades with biconvex parabolic arc sections of radially tapering thickness. Blade shapes that are required to achieve a zero thickness, uniform chordwise loading, constant work spanwise loading are also presented for two examples. In addition, corresponding surface pressure distributions are given. The flow relative to the blade tips has a high subsonic Mach number in the examples that have been computed. The results suggest that at near-sonic relative tip speeds the effective blade shape is dominated by the thickness distribution, with the lift distribution playing only a minor role.

Developing a passive load reduction blade for the DTU 10 MW reference turbine

NASA Astrophysics Data System (ADS)

de Vaal, J. B.; Nygaard, T. A.; Stenbro, R.

2016-09-01

This paper presents the development of a passive load reduction blade for the DTU 10 MW reference wind turbine, using the aero-hydro-servo-elastic analysis tool 3DFloat. Passive load reduction is achieved by introducing sweep to the path of the blade elastic axis, so that out-of-plane bending deflections result in load alleviating torsional deformations of the blade. Swept blades are designed to yield similar annual energy production as a rotor with a reference straight blade. This is achieved by modifying the aerodynamic twist distribution for swept blades based on non-linear blade deflection under steady state loads. The passive load reduction capability of a blade design is evaluated by running a selection of fatigue- and extreme load cases with the analysis tool 3DFloat and determining equivalent fatigue loads, fatigue damage and extreme loads at the blade root and tower base. The influence of sweep on the flutter speed of a blade design is also investigated. A large number of blade designs are evaluated by varying the parameters defining the sweep path of a blade's elastic axis. Results show that a moderate amount of sweep can effectively reduce equivalent fatigue damage and extreme loads, without significantly reducing the flutter speed, or compromising annual energy production.

Optimization of an Active Twist Rotor Blade Planform for Improved Active Response and Forward Flight Performance

NASA Technical Reports Server (NTRS)

Sekula, Martin K; Wilbur, Matthew L.

2014-01-01

A study was conducted to identify the optimum blade tip planform for a model-scale active twist rotor. The analysis identified blade tip design traits which simultaneously reduce rotor power of an unactuated rotor while leveraging aeromechanical couplings to tailor the active response of the blade. Optimizing the blade tip planform for minimum rotor power in forward flight provided a 5 percent improvement in performance compared to a rectangular blade tip, but reduced the vibration control authority of active twist actuation by 75 percent. Optimizing for maximum blade twist response increased the vibration control authority by 50 percent compared to the rectangular blade tip, with little effect on performance. Combined response and power optimization resulted in a blade tip design which provided similar vibration control authority to the rectangular blade tip, but with a 3.4 percent improvement in rotor performance in forward flight.

Study on the Influence of the Main Parameters of Woodworking Saw Blade on the Illumination Value of Band Saw Blade (1)

NASA Astrophysics Data System (ADS)

Gao, Jin-gui; Zhao, Hong-gang; Luo, Lai-peng

2017-04-01

In this paper, MJ3310A band saw machine as the research object, through the Beijing VIBSYS vibration signal acquisition and analysis software illumination value analysis, analysis of different circumstances to find good and crack band saw blade illumination value of the law. The results show that the illuminance of the cracked band saw blade is significantly higher than that of the complete band saw blade illumination value. Under the optimum working conditions, if the band saw blade illumination value exceeds 286 Lux, it can be determined that the band saw blade has at least one crack length greater than 1.68 mm Of the defects, the need for timely replacement band saw blade. So as to rational use of band saw blade, band saw blade on-line fault diagnosis provides a technical basis.

Large, low cost composite wind turbine blades

NASA Technical Reports Server (NTRS)

Gewehr, H. W.

1979-01-01

A woven roving E-glass tape, having all of its structural fibers oriented across the tape width was used in the manufacture of the spar for a wind turbine blade. Tests of a 150 ft composite blade show that the transverse filament tape is capable of meeting structural design requirements for wind turbine blades. Composite blades can be designed for interchangeability with steel blades in the MOD-1 wind generator system. The design, analysis, fabrication, and testing of the 150 ft blade are discussed.

Determination of HART I Blade Structural Properties by Laboratory Testing

NASA Technical Reports Server (NTRS)

Jung, Sung N.; Lau, Benton H.

2012-01-01

The structural properties of higher harmonic Aeroacoustic Rotor Test (HART I) blades were measured using the original set of blades tested in the German-dutch wind tunnel (DNW) in 1994. the measurements include bending and torsion stiffness, geometric offsets, and mass and inertia properties of the blade. the measured properties were compared to the estimated values obtained initially from the blade manufacturer. The previously estimated blade properties showed consistently higher stiffness, up to 30 percent for the flap bending in the blade inboard root section.

Obstacles to implementation of an intervention to improve surgical services in an Ethiopian hospital: a qualitative study of an international health partnership project.

PubMed

Aveling, Emma-Louise; Zegeye, Desalegn Tegabu; Silverman, Michael

2016-08-17

Access to safe surgical care represents a critical gap in healthcare delivery and development in many low- and middle-income countries, including Ethiopia. Quality improvement (QI) initiatives at hospital level may contribute to closing this gap. Many such quality improvement initiatives are carried out through international health partnerships. Better understanding of how to optimise quality improvement in low-income settings is needed, including through partnership-based approaches. Drawing on a process evaluation of an intervention to improve surgical services in an Ethiopian hospital, this paper offers lessons to help meet this need. We conducted a qualitative process evaluation of a quality improvement project which aimed to improve access to surgical services in an Ethiopian referral hospital through better management. Data was collected longitudinally and included: 66 in-depth interviews with surgical staff and project team members; observation (135 h) in the surgery department and of project meetings; project-related documentation. Thematic analysis, guided by theoretical constructs, focused on identifying obstacles to implementation. The project largely failed to achieve its goals. Key barriers related to project design, partnership working and the implementation context, and included: confusion over project objectives and project and partner roles and responsibilities; logistical challenges concerning overseas visits; difficulties in communication; gaps between the time and authority team members had and that needed to implement and engage other staff; limited strategies for addressing adaptive-as opposed to technical-challenges; effects of hierarchy and resource scarcity on QI efforts. While many of the obstacles identified are common to diverse settings, our findings highlight ways in which some features of low-income country contexts amplify these common challenges. We identify lessons for optimising the design and planning of quality improvement interventions within such challenging healthcare contexts, with specific reference to international partnership-based approaches. These include: the need for a funded lead-in phase to clarify and agree goals, roles, mutual expectations and communication strategies; explicitly incorporating adaptive, as well as technical, solutions; transparent management of resources and opportunities; leadership which takes account of both formal and informal power structures; and articulating links between project goals and wider organisational interests.

On the inverse problem of blade design for centrifugal pumps and fans

NASA Astrophysics Data System (ADS)

Kruyt, N. P.; Westra, R. W.

2014-06-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated.

Light intensity of curved laryngoscope blades in Philadelphia emergency departments.

PubMed

Levitan, Richard M; Kelly, John J; Kinkle, William C; Fasano, Charles

2007-09-01

Laryngoscopy and tracheal intubation requires laryngeal exposure and illumination. The objective of this study is to assess variation in laryngoscope lights across different emergency departments (EDs). A convenience sample of 3 Mac #4 blade and handle pairs in each of 17 Philadelphia area EDs was tested with a digital light meter to derive the median lux at the distal tip. For each blade tested, we characterized blade design (American, English, or German) and light type (fiber-illuminated versus conventional bulb-on-blade) and measured light-to-tip distance. A total of 50 blades and handle pairs were tested (one ED had only 2 Mac #4 blades). American designs were the most common (38/50), followed by English (6/50) and German (3/50) designs. Three blades had hybrid design features and acrylic light-conducting fibers. Median luminance varied from 11 lux to 5,627 lux. The glass fiber-illuminated blades (n=13) produced greater luminance (median 1,205 lux; interquartile range [IQR] 726 to 2,176 lux) than bulb-on-blade designs (median 689 lux; IQR 290 to 906 lux). German fiber-illuminated blades produced the highest luminance (median 1,937 lux; IQR 1,453 to 3,782 lux). English bulb-on-blade designs produced more luminance (median 915 lux; IQR 745 to 1270 lux) than American (median 689 lux; IQR 269 to 807 lux). German and English blades had shorter light-to-tip distances (median 51 mm and 47 mm, respectively) than American blades (65 mm). Curved laryngoscope blades in different EDs have marked variation in light intensity. The contribution of luminance to laryngoscopy performance warrants investigation.

The Social Essentials of Learning: An Experimental Investigation of Collaborative Problem Solving and Knowledge Construction in Mathematics Classrooms in Australia and China

ERIC Educational Resources Information Center

Chan, Man Ching Esther; Clarke, David; Cao, Yiming

2018-01-01

Interactive problem solving and learning are priorities in contemporary education, but these complex processes have proved difficult to research. This project addresses the question "How do we optimise social interaction for the promotion of learning in a mathematics classroom?" Employing the logic of multi-theoretic research design,…

Protocol for a national blood transfusion data warehouse from donor to recipient

PubMed Central

van Hoeven, Loan R; Hooftman, Babette H; Janssen, Mart P; de Bruijne, Martine C; de Vooght, Karen M K; Kemper, Peter; Koopman, Maria M W

2016-01-01

Introduction Blood transfusion has health-related, economical and safety implications. In order to optimise the transfusion chain, comprehensive research data are needed. The Dutch Transfusion Data warehouse (DTD) project aims to establish a data warehouse where data from donors and transfusion recipients are linked. This paper describes the design of the data warehouse, challenges and illustrative applications. Study design and methods Quantitative data on blood donors (eg, age, blood group, antibodies) and products (type of product, processing, storage time) are obtained from the national blood bank. These are linked to data on the transfusion recipients (eg, transfusions administered, patient diagnosis, surgical procedures, laboratory parameters), which are extracted from hospital electronic health records. Applications Expected scientific contributions are illustrated for 4 applications: determine risk factors, predict blood use, benchmark blood use and optimise process efficiency. For each application, examples of research questions are given and analyses planned. Conclusions The DTD project aims to build a national, continuously updated transfusion data warehouse. These data have a wide range of applications, on the donor/production side, recipient studies on blood usage and benchmarking and donor–recipient studies, which ultimately can contribute to the efficiency and safety of blood transfusion. PMID:27491665

Hub-mounted actuators for blade pitch collective control

NASA Technical Reports Server (NTRS)

Luecke, Greg R. (Inventor); Jeffery, Philip A. E. (Inventor)

1985-01-01

Blade collective pitch control is provided for a rotor system by rotary actuators located between adjacent blades. Each actuator is connected to the leading edge of one adjacent blade and the trailing edge of the other adjacent blade.

Effects of splitter blades on the flows and characteristics in centrifugal impellers

NASA Astrophysics Data System (ADS)

Miyamoto, Hiroyuki; Nakashima, Yukitoshi; Ohba, Hideki

1992-05-01

A five-flow pressure probe was used to perform flow measurements in an unshrouded impeller and in a shrouded impeller with splitter blades. The effect of the splitter blade on passage flow and impeller performance was analyzed by comparing the results with those of impellers without splitter blades. It is found that, in impellers with splitter blades, the blade loadings tend to become smaller, and the absolute circumferential velocities and total pressures become considerably larger than those in impellers without splitter blades. It is noted that the splitter blade effect on static pressure differs between the unshrouded and shrouded impellers.

Evaluation of Bacterial Contamination of Clipper Blades in Small Animal Private Practice.

PubMed

Mount, Rebecca; Schick, Anthea E; Lewis, Thomas P; Newton, Heide M

2016-01-01

Nosocomial infections are a growing concern in veterinary hospitals, and identifying fomites is imperative to reducing the risk of pathogen transmission. In veterinary medicine, shaving of hair is necessary prior to many procedures. Contaminated clipper blades have been cited as potential fomites involved in the transmission of pathogens in veterinary and human medicine. The primary goal of this study was to evaluate bacterial contamination of clipper blades in veterinary practices. A secondary goal was to assess whether there was an association between bacterial contamination of clipper blades and clipper blade cleaning solutions, clipper blade cleaning protocols, clipper blade storage, and type of practice. Sixty clipper blades from 60 different practices were cultured. Information regarding blade cleaning solutions, protocols, and storage was collected from each practice. Fifty-one percent (31/60) of clipper blades sampled were contaminated with bacteria. Category of cleaning solutions had a significant association with bacterial contamination (P < 0.02). Cleaning frequency (P = 0.55), storage location (P = 0.26), and practice type (P = 0.06) had no significant association with bacterial contamination. This study documented bacterial contamination of clipper blades in veterinary practices, and clipper blades should be considered potential fomites.

Tool mark striations in pig skin produced by stabs from a serrated blade.

PubMed

Pounder, Derrick J; Bhatt, Shivani; Cormack, Lesley; Hunt, Bill A C

2011-03-01

Stab wounds produced by serrated blades are generally indistinguishable from stab wounds produced by non-serrated blades, except when visible tool mark striations are left on severed cartilage. Using a pig-skin experimental model, we explored the possibility that similar striations may be left in skin. Stabs into pig skin were made using a straight spine coarsely serrated blade (121), a drop point finely serrated blade (20), a clip point irregular coarsely serrated blade (20), a drop point coarsely serrated blade (15), and as controls 2 non-serrated blades (40). Tool mark striations could be seen on the skin wall of the stab canal in all stabs made using serrated blades but in none with non-serrated blades.The striation pattern, reflecting the class characteristics of the serrated blade, was the same as that described in cartilage but less well defined. Fixation of the specimen with Carnoy's solution best preserved visible striations, and fixation with formaldehyde after staining with 5% Neutral Red was also satisfactory. Casting with vinyl polysiloxane dental impression material greatly facilitated photo-documentation. Applying the technique to homicidal stabbings may help identify stab wounds produced with serrated blades.

Thermal Imaging of Medical Saw Blades and Guides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dinwiddie, Ralph Barton; Steffner, Thomas E

2007-01-01

Better Than New, LLC., has developed a surface treatment to reduce the friction and wear of orthopedic saw blades and guides. The medical saw blades were thermally imaged while sawing through fresh animal bone and an IR camera was used to measure the blade temperature as it exited the bone. The thermal performance of as-manufactured saw blades was compared to surface-treated blades, and a freshly used blade was used for temperature calibration purposes in order to account for any emissivity changes due to organic transfer layers. Thermal imaging indicates that the treated saw blades cut faster and cooler than untreatedmore » blades. In orthopedic surgery, saw guides are used to perfectly size the bone to accept a prosthesis. However, binding can occur between the blade and guide because of misalignment. This condition increases the saw blade temperature and may result in tissue damage. Both treated ad untreated saw guides were also studied. The treated saw guide operated at a significantly lower temperature than untreated guide. Saw blades and guides that operate at a cooler temperature are expected to reduce the amount of tissue damage (thermal necrosis) and may reduce the number of post-operative complications.« less

UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction.

PubMed

Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej; Eggers, Patrick C F; Olesen, Kim; Byskov, Claus; Pedersen, Gert Frølund

2015-08-12

A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1-5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally.

Structural integrity of wind tunnel wooden fan blades

NASA Technical Reports Server (NTRS)

Young, Clarence P., Jr.; Wingate, Robert T.; Rooker, James R.; Mort, Kenneth W.; Zager, Harold E.

1991-01-01

Information is presented which was compiled by the NASA Inter-Center Committee on Structural Integrity of Wooden Fan Blades and is intended for use as a guide in design, fabrication, evaluation, and assurance of fan systems using wooden blades. A risk assessment approach for existing NASA wind tunnels with wooden fan blades is provided. Also, state of the art information is provided for wooden fan blade design, drive system considerations, inspection and monitoring methods, and fan blade repair. Proposed research and development activities are discussed, and recommendations are provided which are aimed at future wooden fan blade design activities and safely maintaining existing NASA wind tunnel fan blades. Information is presented that will be of value to wooden fan blade designers, fabricators, inspectors, and wind tunnel operations personnel.

Methods and apparatus for rotor blade ice detection

DOEpatents

LeMieux, David Lawrence

2006-08-08

A method for detecting ice on a wind turbine having a rotor and one or more rotor blades each having blade roots includes monitoring meteorological conditions relating to icing conditions and monitoring one or more physical characteristics of the wind turbine in operation that vary in accordance with at least one of the mass of the one or more rotor blades or a mass imbalance between the rotor blades. The method also includes using the one or more monitored physical characteristics to determine whether a blade mass anomaly exists, determining whether the monitored meteorological conditions are consistent with blade icing; and signaling an icing-related blade mass anomaly when a blade mass anomaly is determined to exist and the monitored meteorological conditions are determined to be consistent with icing.

Turbine seal assembly

DOEpatents

Little, David A.

2013-04-16

A seal assembly that limits gas leakage from a hot gas path to one or more disc cavities in a turbine engine. The seal assembly includes a seal apparatus that limits gas leakage from the hot gas path to a respective one of the disc cavities. The seal apparatus comprises a plurality of blade members rotatable with a blade structure. The blade members are associated with the blade structure and extend toward adjacent stationary components. Each blade member includes a leading edge and a trailing edge, the leading edge of each blade member being located circumferentially in front of the blade member's corresponding trailing edge in a direction of rotation of the turbine rotor. The blade members are arranged such that a space having a component in a circumferential direction is defined between adjacent circumferentially spaced blade members.

Multidisciplinary Design Optimization for Glass-Fiber Epoxy-Matrix Composite 5 MW Horizontal-Axis Wind-Turbine Blades

NASA Astrophysics Data System (ADS)

Grujicic, M.; Arakere, G.; Pandurangan, B.; Sellappan, V.; Vallejo, A.; Ozen, M.

2010-11-01

A multi-disciplinary design-optimization procedure has been introduced and used for the development of cost-effective glass-fiber reinforced epoxy-matrix composite 5 MW horizontal-axis wind-turbine (HAWT) blades. The turbine-blade cost-effectiveness has been defined using the cost of energy (CoE), i.e., a ratio of the three-blade HAWT rotor development/fabrication cost and the associated annual energy production. To assess the annual energy production as a function of the blade design and operating conditions, an aerodynamics-based computational analysis had to be employed. As far as the turbine blade cost is concerned, it is assessed for a given aerodynamic design by separately computing the blade mass and the associated blade-mass/size-dependent production cost. For each aerodynamic design analyzed, a structural finite element-based and a post-processing life-cycle assessment analyses were employed in order to determine a minimal blade mass which ensures that the functional requirements pertaining to the quasi-static strength of the blade, fatigue-controlled blade durability and blade stiffness are satisfied. To determine the turbine-blade production cost (for the currently prevailing fabrication process, the wet lay-up) available data regarding the industry manufacturing experience were combined with the attendant blade mass, surface area, and the duration of the assumed production run. The work clearly revealed the challenges associated with simultaneously satisfying the strength, durability and stiffness requirements while maintaining a high level of wind-energy capture efficiency and a lower production cost.

Drive system for the retraction/extension of variable diameter rotor systems

NASA Technical Reports Server (NTRS)

Gmirya, Yuriy (Inventor)

2003-01-01

A drive system for a variable diameter rotor (VDR) system includes a plurality of rotor blade assemblies with inner and outer rotor blade segments. The outer blade segment being telescopically mounted to the inner blade segment. The VDR retraction/extension system includes a drive housing mounted at the root of each blade. The housing supports a spool assembly, a harmonic gear set and an electric motor. The spool assembly includes a pair of counter rotating spools each of which drive a respective cable which extends through the interior of the inboard rotor blade section and around a pulley mounted to the outboard rotor blade section. In operation, the electric motor drives the harmonic gear set which rotates the counter rotating spools. Rotation of the spools causes the cables to be wound onto or off their respective spool consequently effecting retraction/extension of the pulley and the attached outboard rotor blade section relative the inboard rotor blade section. As each blade drive system is independently driven by a separate electrical motor, each independent VDR blade assembly is independently positionable.

On the Cutting Performance of Segmented Diamond Blades when Dry-Cutting Concrete.

PubMed

Sánchez Egea, A J; Martynenko, V; Martínez Krahmer, D; López de Lacalle, L N; Benítez, A; Genovese, G

2018-02-09

The objective of the present study is to analyze and compare the cutting performance of segmented diamond blades when dry-cutting concrete. A cutting criteria is proposed to characterize the wear of the blades by measuring the variation of the external diameter and the weight loss of the blade. The results exhibit the cutting blade SB-A, which has twice the density of diamonds and large contact area, exhibits less wear even though the material removal rate is higher compared with the other two cutting blades. Additionally, the surface topography of the different blades is evaluated to examine the impact of wear depending on the surface profile and the distribution of the diamonds in the blade's matrix. Large number of diamonds pull-out are found in blades type SB-C, which additionally shows the worst wear resistant capability. As a conclusion, the cutting efficiency of the blade is found to be related to the density of embedded diamonds and the type of the surface profile of the cutting blade after reaching the stop criteria.

Study on influence of crack on the blade status using FBGs

NASA Astrophysics Data System (ADS)

Xu, Gang; Liang, Lei; Li, Jianzhi; Mei, Huaping; Li, Hongli; Liu, Yijun

2018-03-01

The status detection for rotating parts is difficult since the sensor is influenced by the rotation in the inflammable, explosive, and strong magnetic environment. Based on the fiber Bragg grating sensing technology, this paper studies the influence of the natural frequency and deformation of a rotor blade affected by the size of crack in the blade. Test results show that the speed of the equipment and blade excited vibration frequency are two main factors or deformation and vibration frequency of the blade. With an increase in the crack depth, the blade deformation is increased while the stimulated natural frequency of the blade is decreased; at a low rotational speed, the deformation is mainly caused by the rotating speed of the blade. On the contrary, the vibration blade itself contributes to the deformation at a high speed. During the process of full speed rotation, the influence of the rotational speed on the blade deformation almost remains the same, and the influence of the natural vibration on blade deformation is increased with an increase in the rotational speed.

Study on influence of crack on the blade status using FBGs

NASA Astrophysics Data System (ADS)

Xu, Gang; Liang, Lei; Li, Jianzhi; Mei, Huaping; Li, Hongli; Liu, Yijun

2017-12-01

The status detection for rotating parts is difficult since the sensor is influenced by the rotation in the inflammable, explosive, and strong magnetic environment. Based on the fiber Bragg grating sensing technology, this paper studies the influence of the natural frequency and deformation of a rotor blade affected by the size of crack in the blade. Test results show that the speed of the equipment and blade excited vibration frequency are two main factors or deformation and vibration frequency of the blade. With an increase in the crack depth, the blade deformation is increased while the stimulated natural frequency of the blade is decreased; at a low rotational speed, the deformation is mainly caused by the rotating speed of the blade. On the contrary, the vibration blade itself contributes to the deformation at a high speed. During the process of full speed rotation, the influence of the rotational speed on the blade deformation almost remains the same, and the influence of the natural vibration on blade deformation is increased with an increase in the rotational speed.

Aeroelastic Stability of Rotor Blades Using Finite Element Analysis

NASA Technical Reports Server (NTRS)

Chopra, I.; Sivaneri, N.

1982-01-01

The flutter stability of flap bending, lead-lag bending, and torsion of helicopter rotor blades in hover is investigated using a finite element formulation based on Hamilton's principle. The blade is divided into a number of finite elements. Quasi-steady strip theory is used to evaluate the aerodynamic loads. The nonlinear equations of motion are solved for steady-state blade deflections through an iterative procedure. The equations of motion are linearized assuming blade motion to be a small perturbation about the steady deflected shape. The normal mode method based on the coupled rotating natural modes is used to reduce the number of equations in the flutter analysis. First the formulation is applied to single-load-path blades (articulated and hingeless blades). Numerical results show very good agreement with existing results obtained using the modal approach. The second part of the application concerns multiple-load-path blades, i.e. bearingless blades. Numerical results are presented for several analytical models of the bearingless blade. Results are also obtained using an equivalent beam approach wherein a bearingless blade is modelled as a single beam with equivalent properties. Results show the equivalent beam model.

A Take Stock of Turbine Blades Failure Phenomenon

NASA Astrophysics Data System (ADS)

Roy, Abhijit

2018-02-01

Turbine Blade design and engineering is one of the most complicated and important aspects of turbine technology. Experiments with blades can be simple or very complicated, depending upon parameters of analysis. Turbine blades are subjected to vigorous environments, such as high temperatures, high stresses, and a potentially high vibration environment. All these factors can lead to blade failures, which can destroy the turbine, and engine, so careful design is the prime consideration to resist those conditions. A high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of machinery is common failure mode for turbine machine. Continuous study and investigation on failure of turbine blades are going on since last five decades. Some review papers published during these days aiming to present a review on recent studies and investigations done on failures of turbine blades. All the detailed literature related with the turbine blades has not been described but emphasized to provide all the methodologies of failures adopted by various researches to investigate turbine blade. This paper illustrate on various factors of failure.

The SNL100-03 Blade: Design Studies with Flatback Airfoils for the Sandia 100-meter Blade.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffith, Daniel; Richards, Phillip William

A series of design studies were performed to inv estigate the effects of flatback airfoils on blade performance and weight for large blades using the Sandi a 100-meter blade designs as a starting point. As part of the study, the effects of varying the blade slenderness on blade structural performance was investigated. The advantages and disadvantages of blad e slenderness with respect to tip deflection, flap- wise & edge-wise fatigue resistance, panel buckling capacity, flutter speed, manufacturing labor content, blade total weight, and aerodynamic design load magn itude are quantified. Following these design studies, a final blade design (SNL100-03) wasmore » prod uced, which was based on a highly slender design using flatback airfoils. The SNL100-03 design with flatback airfoils has weight of 49 tons, which is about 16% decrease from its SNL100-02 predecessor that used conventional sharp trailing edge airfoils. Although not systematically optimized, the SNL100 -03 design study provides an assessment of and insight into the benefits of flatback airfoils for la rge blades as well as insights into the limits or negative consequences of high blade slenderness resulting from a highly slender SNL100-03 planform as was chosen in the final design definition. This docum ent also provides a description of the final SNL100-03 design definition and is intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-03, which are made publicly available. A summary of the major findings of the Sandia 100-meter blade development program, from the initial SNL100-00 baseline blade through the fourth SNL100-03 blade study, is provided. This summary includes the major findings and outcomes of blade d esign studies, pathways to mitigate the identified large blade design drivers, and tool development that were produced over the course of this five-year research program. A summary of large blade tec hnology needs and research opportunities is also presented.« less

Periodic acoustic radiation from a low aspect ratio propeller

NASA Astrophysics Data System (ADS)

Muench, John David

An experimental program was conducted with the objective of providing high fidelity measurements of propeller inflow, unsteady blade surface pressures, and discrete acoustic radiation over a wide range of speeds. Anechoic wind tunnel experiments were preformed using the SISUP propeller. The upstream stator blades generate large wake deficits that result in periodic unsteady blade forces that acoustically radiate at blade passing frequency and higher harmonics. The experimental portion of this research successfully measured the inflow velocity, blade span unsteady pressures and directive characteristics of the blade-rate radiated noise associated with this complex propeller geometry while the propeller was operating on design. The spatial harmonic decomposition of the inflow revealed significant coefficients at 8, 16 and 24. The magnitude of the unsteady blade forces scale as U4 and linearly shift in frequency with speed. The magnitude of the discrete frequency acoustic levels associated with blade rate scale as U6 and also shift linearly with speed. At blade-rate, the far-field acoustic directivity has a dipole-like directivity oriented perpendicular to the inflow. At the first harmonic of blade-rate, the far-field directivity is not as well defined. The experimental inflow and blade surface pressure results were used to generate an acoustic prediction at blade rate based on a blade strip theory model developed by Blake (1986). The predicted acoustic levels were compared to the experimental results. The model adequately predicts the measured sound field at blade rate at 120 ft/sec. Radiated noise at blade-rate for 120 ft/s can be described by a dipole, whose orientation is perpendicular to the flow and is generated by the interaction of the rotating propeller with the 8th harmonic of the inflow. At blade-rate for 60 ft/s, the model under predicts measured levels. At the first harmonic of blade-rate, for 120 ft/s, the sound field is described as a combination of dipole sources, one generated by the 16 th harmonic, perpendicular to the inflow, and the other generated by the 12th harmonic of the inflow parallel to the inflow. At the first harmonic of blade-rate for 60 ft/s, the model under predicts measured levels.

Heat generation by two different saw blades used for tibial plateau leveling osteotomies.

PubMed

Bachelez, Andreas; Martinez, Steven A

2012-01-01

During tibial plateau leveling osteotomy (TPLO) the saw blade produces frictional heat. The purpose of this study was to evaluate and compare heat generated by two TPLO blade designs (Slocum Enterprises [SE] and New Generation Devices [NDG]), with or without irrigation, on cadaveric canine tibias. Thirty-six paired tibias were used to continuously measure bone temperatures during osteotomy through both cortices (i.e., the cis and trans cortices). Each pair was assigned to either an irrigation or nonirrigation group during osteotomy, and each tibia within a pair was osteotomized using a different saw blade design. Saw blade temperatures were recorded and temperatures were compared for all combinations of blade type, cortex, and irrigation. In the cis cortex group, the SE blade generated more bone heat than the NGD blade (P=0.0258). Significant differences in temperature generation between saw blade types were seen only when the osteotomy site was not irrigated (P=0.0156). For all variables measured, bone and saw blade temperature generation was lower with irrigation (P<0.05). None of the osteotomies performed with either saw blade produced a critical duration of damaging temperature ranges in this study. Although saw blade design and irrigation influence heat generation during the TPLO, the potential for bone thermal damage during TPLO is low. The use of the NGD blade with irrigation is recommended.

Experimental Investigation of Air-Cooled Turbine Blades in Turbojet Engine. 7: Rotor-Blade Fabrication Procedures

NASA Technical Reports Server (NTRS)

Long, Roger A.; Esgar, Jack B.

1951-01-01

An experimental investigation was conducted to determine the cooling effectiveness of a wide variety of air-cooled turbine-blade configurations. The blades, which were tested in the turbine of a - commercial turbojet engine that was modified for this investigation by replacing two of the original blades with air-cooled blades located diametrically opposite each other, are untwisted, have no aerodynamic taper, and have essentially the same external profile. The cooling-passage configuration is different for each blade, however. The fabrication procedures were varied and often unique. The blades were fabricated using methods most suitable for obtaining a small number of blades for use in the cooling investigations and therefore not all the fabrication procedures would be directly applicable to production processes, although some of the ideas and steps might be useful. Blade shells were obtained by both casting and forming. The cast shells were either welded to the blade base or cast integrally with the base. The formed shells were attached to the base by a brazing and two welding methods. Additional surface area was supplied in the coolant passages by the addition of fins or tubes that were S-brazed. to the shell. A number of blades with special leading- and trailing-edge designs that provided added cooling to these areas were fabricated. The cooling effectiveness and purposes of the various blade configurations are discussed briefly.

Dynamic response of active twist rotor blades

NASA Astrophysics Data System (ADS)

Cesnik, Carlos E. S.; Shin, Sang Joon; Wilbur, Matthew L.

2001-02-01

Dynamic characteristics of active twist rotor (ATR) blades are investigated analytically and experimentally in this paper. The ATR system is intended for vibration and potentially for noise reductions in helicopters through individual blade control. An aeroelastic model is developed to identify frequency response characteristics of the ATR blade with integral, generally anisotropic, strain actuators embedded in its composite construction. An ATR prototype blade was designed and manufactured to experimentally study the vibration reduction capabilities of such systems. Several bench and hover tests were conducted and those results are presented and discussed here. Selected results on sensitivity of the ATR system to collective setting (i.e. blade loading), blade rpm (i.e. centrifugal force and blade station velocity), and media density (i.e. altitude) are presented. They indicated that the twist actuation authority of the ATR blade is independent of the collective setting up to approximately 10P, and dependent on rotational speed and altitude near the torsional resonance frequency due to its dependency on the aerodynamic damping. The proposed model captures very well the physics and sensitivities to selected test parameters of the ATR system. The numerical result of the blade torsional loads show an average error of 20% in magnitude and virtually no difference in phase for the blade frequency response. Overall, the active blade model is in very good agreement with the experiments and can be used to analyze and design future active helicopter blade systems.

Rotating hot-wire investigation of the vortex responsible for blade-vortex interaction noise

NASA Technical Reports Server (NTRS)

Fontana, Richard Remo

1988-01-01

This distribution of the circumferential velocity of the vortex responsible for blade-vortex interaction noise was measured using a rotating hot-wire rake synchronously meshed with a model helicopter rotor at the blade passage frequency. Simultaneous far-field acoustic data and blade differential pressure measurements were obtained. Results show that the shape of the measured far-field acoustic blade-vortex interaction signature depends on the blade-vortex interaction geometry. The experimental results are compared with the Widnall-Wolf model for blade-vortex interaction noise.

Probabilistic Evaluation of Blade Impact Damage

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Abumeri, G. H.

2003-01-01

The response to high velocity impact of a composite blade is probabilistically evaluated. The evaluation is focused on quantifying probabilistically the effects of uncertainties (scatter) in the variables that describe the impact, the blade make-up (geometry and material), the blade response (displacements, strains, stresses, frequencies), the blade residual strength after impact, and the blade damage tolerance. The results of probabilistic evaluations results are in terms of probability cumulative distribution functions and probabilistic sensitivities. Results show that the blade has relatively low damage tolerance at 0.999 probability of structural failure and substantial at 0.01 probability.

Rotor blade system with reduced blade-vortex interaction noise

NASA Technical Reports Server (NTRS)

Leishman, John G. (Inventor); Han, Yong Oun (Inventor)

2005-01-01

A rotor blade system with reduced blade-vortex interaction noise includes a plurality of tube members embedded in proximity to a tip of each rotor blade. The inlets of the tube members are arrayed at the leading edge of the blade slightly above the chord plane, while the outlets are arrayed at the blade tip face. Such a design rapidly diffuses the vorticity contained within the concentrated tip vortex because of enhanced flow mixing in the inner core, which prevents the development of a laminar core region.

Aircraft and Engine Development Testing

DTIC Science & Technology

1986-09-01

Control in Flight * Integrated Inlet- engine * Power/weight Exceeds Unity F-lll * Advanced Engines * Augmented Turbofan * High Turbine Temperature...residence times). Also, fabrication of a small scale "hot" engine with rotating components such as compressors and turbines with cooled blades , is...capabil- ities are essential to meet the needs of current and projected aircraft and engine programs. The required free jet nozzles should be capable of

Reliability Prediction, Assessment and Growth

DTIC Science & Technology

1976-03-15

Technical contributors to the report were D. Kos, L. Townsend, J. Schiller, N . Thomopoulos and V. Allen. On the part of the government, the project was...Life Penodj n Useful Life Overall Life Characteristic Curve ] IH Weorout Stress Related _ Failures ŕ / . Wearouf Failures...costs. It should be pointed out that maintenance data usually include 22 Table 2-1 SELECTED ARMY HELICOPTERS 4 R =rad.of blade N =number NUMBER

The Snowmastodon Project: cutting-edge science on the blade of a bulldozer

USGS Publications Warehouse

Pigati, Jeffery S.; Miller, Ian M.; Johnson, Kirk R.

2015-01-01

Cutting-edge science happens at a variety of scales, from the individual and intimate to the large-scale and collaborative. The publication of a special issue of Quaternary Research in Nov. 2014 dedicated to the scientific findings of the “Snowmastodon Project” highlights what can be done when natural history museums, governmental agencies, and academic institutions work toward a common goal.

AERODYNAMIC AND BLADING DESIGN OF MULTISTAGE AXIAL FLOW COMPRESSORS

NASA Technical Reports Server (NTRS)

Crouse, J. E.

1994-01-01

The axial-flow compressor is used for aircraft engines because it has distinct configuration and performance advantages over other compressor types. However, good potential performance is not easily obtained. The designer must be able to model the actual flows well enough to adequately predict aerodynamic performance. This computer program has been developed for computing the aerodynamic design of a multistage axial-flow compressor and, if desired, the associated blading geometry input for internal flow analysis. The aerodynamic solution gives velocity diagrams on selected streamlines of revolution at the blade row edges. The program yields aerodynamic and blading design results that can be directly used by flow and mechanical analysis codes. Two such codes are TSONIC, a blade-to-blade channel flow analysis code (COSMIC program LEW-10977), and MERIDL, a more detailed hub-to-shroud flow analysis code (COSMIC program LEW-12966). The aerodynamic and blading design program can reduce the time and effort required to obtain acceptable multistage axial-flow compressor configurations by generating good initial solutions and by being compatible with available analysis codes. The aerodynamic solution assumes steady, axisymmetric flow so that the problem is reduced to solving the two-dimensional flow field in the meridional plane. The streamline curvature method is used for the iterative aerodynamic solution at stations outside of the blade rows. If a blade design is desired, the blade elements are defined and stacked within the aerodynamic solution iteration. The blade element inlet and outlet angles are established by empirical incidence and deviation angles to the relative flow angles of the velocity diagrams. The blade element centerline is composed of two segments tangentially joined at a transition point. The local blade angle variation of each element can be specified as a fourth-degree polynomial function of path distance. Blade element thickness can also be specified with fourth-degree polynomial functions of path distance from the maximum thickness point. Input to the aerodynamic and blading design program includes the annulus profile, the overall compressor mass flow, the pressure ratio, and the rotative speed. A number of input parameters are also used to specify and control the blade row aerodynamics and geometry. The output from the aerodynamic solution has an overall blade row and compressor performance summary followed by blade element parameters for the individual blade rows. If desired, the blade coordinates in the streamwise direction for internal flow analysis codes and the coordinates on plane sections through blades for fabrication drawings may be stored and printed. The aerodynamic and blading design program for multistage axial-flow compressors is written in FORTRAN IV for batch execution and has been implemented on an IBM 360 series computer with a central memory requirement of approximately 470K of 8 bit bytes. This program was developed in 1981.

Permeability and Strength Measurements on Sintered, Porous, Hollow Turbine Blades Made by the American Electro Metal Corporation under Office of Naval Research Contract N-ONR-295 (01)

NASA Technical Reports Server (NTRS)

Richards, Hadley T.; Livingood, N.B.

1954-01-01

An experimental investigation was made to determine the permeability and strength characteristics of a number of sintered, porous, hollow turbine rotor blades and to determine the effectiveness of the blade fabrication method on permeability control. The test blades were fabricated by the American Electro Metal Corporation under a contract with the Office of Naval Research, Department of the Navy, and were submitted to the NACA for testing. Of the 22 test blades submitted, ten were sintered but not coined, five were sintered and coined, and seven were sintered and not coined but contained perforated reinforcements integral with the blade shells. Representative samples of each group of blades were tested. Large variations in permeability in both chordwise and spanwise directions were found. Local deviations as large as 155 to -85 percent from prescribed values were found in chordwise permeability. Only one blade, an uncoined one, had a chordwise permeability variations which reasonably approached that specified. Even for this blade, local deviations exceeded 10 percent. Spanwise permeability, specified to be held constant, varied as much as 50 percent from root to tip for both an uncoined and a coined blade. Previous NACA analyses have shown that in order to maintain proper control of blade wall temperatures, permeability variations must not exceed plus or minus 10 percent. Satisfactory control of permeability in either the chordwise or the spanwise direction was not achieved in the blades tested. Spin tests made at room temperature for six blades revealed the highest material rupture strength to be 8926 pounds per square inch. This value is about one third the strength required for rotor blades in present-day turbojet engines. The lowest value of blade strength was 1436 pounds per square inch.

Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance.

PubMed

Al-Khudairi, Othman; Hadavinia, Homayoun; Little, Christian; Gillmore, Gavin; Greaves, Peter; Dyer, Kirsten

2017-10-03

In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i) as received blade (ii) when a crack of 200 mm was introduced between the web and the spar cap and (iii) when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM) which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure.

Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance

PubMed Central

Al-Khudairi, Othman; Little, Christian; Gillmore, Gavin; Greaves, Peter; Dyer, Kirsten

2017-01-01

In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i) as received blade (ii) when a crack of 200 mm was introduced between the web and the spar cap and (iii) when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM) which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure. PMID:28972548

Cloud County Community College Wind Energy Technology Project and Renewable Energy Center of Excellence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graham, Bruce

Cloud County Community College's (CCCC) Wind Energy Technology (WET) program is a leader in the renewable energy movement across Kansas and the USA. The field of renewable energy is a growing industry which continues to experience high demand for career opportunities. This CCCC/DOE project entailed two phases: 1) the installation of two Northwind 100 wind turbines, and 2) the continued development of the WET program curriculum, including enhancement of the CCCC Blade Repair Certificate program. This report provides a technical account of the total work performed, and is a comprehensive description of the results achieved.

Transportation of Large Wind Components: A Review of Existing Geospatial Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mooney, Meghan; Maclaurin, Galen

2016-09-01

This report features the geospatial data component of a larger project evaluating logistical and infrastructure requirements for transporting oversized and overweight (OSOW) wind components. The goal of the larger project was to assess the status and opportunities for improving the infrastructure and regulatory practices necessary to transport wind turbine towers, blades, and nacelles from current and potential manufacturing facilities to end-use markets. The purpose of this report is to summarize existing geospatial data on wind component transportation infrastructure and to provide a data gap analysis, identifying areas for further analysis and data collection.

NASA Subsonic Rotary Wing Project - Structures and Materials Discipline

NASA Technical Reports Server (NTRS)

Halbig, Michael C.; Johnson, Susan M.

2008-01-01

The Structures & Materials Discipline within the NASA Subsonic Rotary Wing Project is focused on developing rotorcraft technologies. The technologies being developed are within the task areas of: 5.1.1 Life Prediction Methods for Engine Structures & Components 5.1.2 Erosion Resistant Coatings for Improved Turbine Blade Life 5.2.1 Crashworthiness 5.2.2 Methods for Prediction of Fatigue Damage & Self Healing 5.3.1 Propulsion High Temperature Materials 5.3.2 Lightweight Structures and Noise Integration The presentation will discuss rotorcraft specific technical challenges and needs as well as details of the work being conducted in the six task areas.

Demonstration of an elastically coupled twist control concept for tilt rotor blade application

NASA Technical Reports Server (NTRS)

Lake, R. C.; Nixon, M. W.; Wilbur, M. L.; Singleton, J. D.; Mirick, P. H.

1994-01-01

The purpose of this Note is to present results from an analytic/experimental study that investigated the potential for passively changing blade twist through the use of extension-twist coupling. A set of composite model rotor blades was manufactured from existing blade molds for a low-twist metal helicopter rotor blade, with a view toward establishing a preliminary proof concept for extension-twist-coupled rotor blades. Data were obtained in hover for both a ballasted and unballasted blade configuration in sea-level atmospheric conditions. Test data were compared with results obtained from a geometrically nonlinear analysis of a detailed finite element model of the rotor blade developed in MSC/NASTRAN.

Modeling Tool Advances Rotorcraft Design

NASA Technical Reports Server (NTRS)

2007-01-01

Continuum Dynamics Inc. (CDI), founded in 1979, specializes in advanced engineering services, including fluid dynamic modeling and analysis for aeronautics research. The company has completed a number of SBIR research projects with NASA, including early rotorcraft work done through Langley Research Center, but more recently, out of Ames Research Center. NASA Small Business Innovation Research (SBIR) grants on helicopter wake modeling resulted in the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), a tool for studying helicopter and tiltrotor unsteady free wake modeling, including distributed and integrated loads, and performance prediction. Application of the software code in a blade redesign program for Carson Helicopters, of Perkasie, Pennsylvania, increased the payload and cruise speeds of its S-61 helicopter. Follow-on development resulted in a $24 million revenue increase for Sikorsky Aircraft Corporation, of Stratford, Connecticut, as part of the company's rotor design efforts. Now under continuous development for more than 25 years, CHARM models the complete aerodynamics and dynamics of rotorcraft in general flight conditions. CHARM has been used to model a broad spectrum of rotorcraft attributes, including performance, blade loading, blade-vortex interaction noise, air flow fields, and hub loads. The highly accurate software is currently in use by all major rotorcraft manufacturers, NASA, the U.S. Army, and the U.S. Navy.

Control strategies for wind farm power optimization: LES study

NASA Astrophysics Data System (ADS)

Ciri, Umberto; Rotea, Mario; Leonardi, Stefano

2017-11-01

Turbines in wind farms operate in off-design conditions as wake interactions occur for particular wind directions. Advanced wind farm control strategies aim at coordinating and adjusting turbine operations to mitigate power losses in such conditions. Coordination is achieved by controlling on upstream turbines either the wake intensity, through the blade pitch angle or the generator torque, or the wake direction, through yaw misalignment. Downstream turbines can be adapted to work in waked conditions and limit power losses, using the blade pitch angle or the generator torque. As wind conditions in wind farm operations may change significantly, it is difficult to determine and parameterize the variations of the coordinated optimal settings. An alternative is model-free control and optimization of wind farms, which does not require any parameterization and can track the optimal settings as conditions vary. In this work, we employ a model-free optimization algorithm, extremum-seeking control, to find the optimal set-points of generator torque, blade pitch and yaw angle for a three-turbine configuration. Large-Eddy Simulations are used to provide a virtual environment to evaluate the performance of the control strategies under realistic, unsteady incoming wind. This work was supported by the National Science Foundation, Grants No. 1243482 (the WINDINSPIRE project) and IIP 1362033 (I/UCRC WindSTAR). TACC is acknowledged for providing computational time.

An experimental study of the sensitivity of helicopter rotor blade tracking to root pitch adjustment in hover

NASA Technical Reports Server (NTRS)

Wilkie, W. Keats; Langston, Chester W.; Mirick, Paul H.; Singleton, Jeffrey D.; Wilbur, Matthew L.; Yeager, William T., Jr.

1991-01-01

The sensitivity of blade tracking in hover to variations in root pitch was examined for two rotor configurations. Tests were conducted using a four bladed articulated rotor mounted on the NASA-Army aeroelastic rotor experimental system (ARES). Two rotor configurations were tested: one consisting of a blade set with flexible fiberglass spars and one with stiffer (by a factor of five in flapwise and torsional stiffnesses) aluminum spars. Both blade sets were identical in planform and airfoil distribution and were untwisted. The two configurations were ballasted to the same Lock number so that a direct comparison of the tracking sensitivity to a gross change in blade stiffness could be made. Experimental results show no large differences between the two sets of blades in the sensitivity of the blade tracking to root pitch adjustments. However, a measurable reduction in intrack coning of the fiberglass spar blades with respect to the aluminum blades is noted at higher rotor thrust conditions.

An analysis of blade vortex interaction aerodynamics and acoustics

NASA Technical Reports Server (NTRS)

Lee, D. J.

1985-01-01

The impulsive noise associated with helicopter flight due to Blade-Vortex Interaction, sometimes called blade slap is analyzed especially for the case of a close encounter of the blade-tip vortex with a following blade. Three parts of the phenomena are considered: the tip-vortex structure generated by the rotating blade, the unsteady pressure produced on the following blade during the interaction, and the acoustic radiation due to the unsteady pressure field. To simplify the problem, the analysis was confined to the situation where the vortex is aligned parallel to the blade span in which case the maximum acoustic pressure results. Acoustic radiation due to the interaction is analyzed in space-fixed coordinates and in the time domain with the unsteady pressure on the blade surface as the source of chordwise compact, but spanwise non-compact radiation. Maximum acoustic pressure is related to the vortex core size and Reynolds number which are in turn functions of the blade-tip aerodynamic parameters. Finally noise reduction and performance are considered.

Effect of the number of blades and solidity on the performance of a vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Delafin, PL; Nishino, T.; Wang, L.; Kolios, A.

2016-09-01

Two, three and four bladed ϕ-shape Vertical Axis Wind Turbines are simulated using a free-wake vortex model. Two versions of the three and four bladed turbines are considered, one having the same chord length as the two-bladed turbine and the other having the same solidity as the two-bladed turbine. Results of the two-bladed turbine are validated against published experimental data of power coefficient and instantaneous torque. The effect of solidity on the power coefficient is presented and the instantaneous torque, thrust and lateral force of the two-, three- and four-bladed turbines are compared for the same solidity. It is found that increasing the number of blades from two to three significantly reduces the torque, thrust and lateral force ripples. Adding a fourth blade further reduces the ripples except for the torque at low tip speed ratio. This work aims to help choosing the number of blades during the design phase of a vertical axis wind turbine.

Shaft instantaneous angular speed for blade vibration in rotating machine

NASA Astrophysics Data System (ADS)

Gubran, Ahmed A.; Sinha, Jyoti K.

2014-02-01

Reliable blade health monitoring (BHM) in rotating machines like steam turbines and gas turbines, is a topic of research since decades to reduce machine down time, maintenance costs and to maintain the overall safety. Transverse blade vibration is often transmitted to the shaft as torsional vibration. The shaft instantaneous angular speed (IAS) is nothing but the representing the shaft torsional vibration. Hence the shaft IAS has been extracted from the measured encoder data during machine run-up to understand the blade vibration and to explore the possibility of reliable assessment of blade health. A number of experiments on an experimental rig with a bladed disk were conducted with healthy but mistuned blades and with different faults simulation in the blades. The measured shaft torsional vibration shows a distinct difference between the healthy and the faulty blade conditions. Hence, the observations are useful for the BHM in future. The paper presents the experimental setup, simulation of blade faults, experiments conducted, observations and results.

An experimental investigation of the helicopter rotor blade element airloads on a model rotor in the blade stall regime

NASA Technical Reports Server (NTRS)

Fisher, R. K., Jr.; Tompkins, J. E.; Bobo, C. J.; Child, R. F.

1971-01-01

A wind tunnel test program was conducted on an eight foot diameter model rotor system to determine blade element airloads characteristics in the unstalled and stalled flight regimes. The fully articulated model rotor system utilized three blades with a Vertol 23010-1.58 airfoil section, the blades being 1/7.5 scale models of the Ch-47C rotor blades. Instrumentation was incorporated at the blade 75% radial station to measure pressure and skin friction distributions, surface streamline directions and local angle of attack. The test program was conducted in three phases; non-rotating, hover and forward flight at advance ratios of 0.15, 0.35 and 0.60. Test data were analyzed with respect to providing insight to the mechanisms affecting blade stall, particularly retreating blade stall during forward flight conditions. From such data, an assessment was made as to the applicability of current theoretical analyses used for the prediction of blade element airloads in the stall regime.

A review of turbomachinery blade-row interaction research

NASA Technical Reports Server (NTRS)

Smith, Todd E.

1988-01-01

Analytical and experimental research in the area of unsteady aerodynamics of turbomachinery has conventionally been applied to blading which oscillates when placed in a uniformly flowing fluid. Comparatively less effort has been offered for the study of blading which is subjected to nonuniformities within the flow field. The fluid dynamic environment of a blade-row embedded within multi-stage turbomachines is dominated by such highly unsteady fluid flow conditions. The production of wakes and circumferential pressure variations from adjacent blade-rows causes large unsteady energy transfers between the fluid and the blades. Determination of the forced response of a blade requires the ability to predict the unsteady loads which are induced by these aerodynamic sources. A review of research publications was done to determine recent investigations of the response of turbomachinery blading subjected to aerodynamic excitations. Such excitations are a direct result of the blade-row aerodynamic interaction which occurs between adjacent cascades of blades. The reports and papers reviewed have been organized into areas emphasizing experimental or analytical efforts.

Structural dynamics of shroudless, hollow fan blades with composite in-lays

NASA Technical Reports Server (NTRS)

Aiello, R. A.; Hirschbein, M. S.; Chamis, C. C.

1982-01-01

Structural and dynamic analyses are presented for a shroudless, hollow titanium fan blade proposed for future use in aircraft turbine engines. The blade was modeled and analyzed using the composite blade structural analysis computer program (COBSTRAN); an integrated program consisting of mesh generators, composite mechanics codes, NASTRAN, and pre- and post-processors. Vibration and impact analyses are presented. The vibration analysis was conducted with COBSTRAN. Results show the effect of the centrifugal force field on frequencies, twist, and blade camber. Bird impact analysis was performed with the multi-mode blade impact computer program. This program uses the geometric model and modal analysis from the COBSTRAN vibration analysis to determine the gross impact response of the fan blades to bird strikes. The structural performance of this blade is also compared to a blade of similar design but with composite in-lays on the outer surface. Results show that the composite in-lays can be selected (designed) to substantially modify the mechanical performance of the shroudless, hollow fan blade.

Dynamic analysis method for prevention of failure in the first-stage low-pressure turbine blade with two-finger root

NASA Astrophysics Data System (ADS)

Park, Jung-Yong; Jung, Yong-Keun; Park, Jong-Jin; Kang, Yong-Ho

2002-05-01

Failures of turbine blades are identified as the leading causes of unplanned outages for steam turbine. Accidents of low-pressure turbine blade occupied more than 70 percent in turbine components. Therefore, the prevention of failures for low pressure turbine blades is certainly needed. The procedure is illustrated by the case study. This procedure is used to guide, and support the plant manager's decisions to avoid a costly, unplanned outage. In this study, we are trying to find factors of failures in LP turbine blade and to make three steps to approach the solution of blade failure. First step is to measure natural frequency in mockup test and to compare it with nozzle passing frequency. Second step is to use FEM and to calculate the natural frequencies of 7 blades and 10 blades per group in BLADE code. Third step is to find natural frequencies of grouped blade off the nozzle passing frequency.

Computer Programs (Turbomachinery)

NASA Technical Reports Server (NTRS)

1978-01-01

NASA computer programs are extensively used in design of industrial equipment. Available from the Computer Software Management and Information Center (COSMIC) at the University of Georgia, these programs are employed as analysis tools in design, test and development processes, providing savings in time and money. For example, two NASA computer programs are used daily in the design of turbomachinery by Delaval Turbine Division, Trenton, New Jersey. The company uses the NASA splint interpolation routine for analysis of turbine blade vibration and the performance of compressors and condensers. A second program, the NASA print plot routine, analyzes turbine rotor response and produces graphs for project reports. The photos show examples of Delaval test operations in which the computer programs play a part. In the large photo below, a 24-inch turbine blade is undergoing test; in the smaller photo, a steam turbine rotor is being prepared for stress measurements under actual operating conditions; the "spaghetti" is wiring for test instrumentation

Milestone Deliverable: FY18-Q1: Deploy production sliding mesh capability with linear solver benchmarking.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domino, Stefan P.

2017-12-01

This milestone was focused on deploying and verifying a “sliding-mesh interface,” and establishing baseline timings for blade-resolved simulations of a sub-MW-scale turbine. In the ExaWind project, we are developing both sliding-mesh and overset-mesh approaches for handling the rotating blades in an operating wind turbine. In the sliding-mesh approach, the turbine rotor and its immediate surrounding fluid are captured in a “disk” that is embedded in the larger fluid domain. The embedded fluid is simulated in a coordinate system that rotates with the rotor. It is important that the coupling algorithm (and its implementation) between the rotating and inertial discrete modelsmore » maintains the accuracy of the numerical methods on either side of the interface, i.e., the interface is “design order.”« less

Highly damped kinematic coupling for precision instruments

DOEpatents

Hale, Layton C.; Jensen, Steven A.

2001-01-01

A highly damped kinematic coupling for precision instruments. The kinematic coupling provides support while causing essentially no influence to its nature shape, with such influences coming, for example, from manufacturing tolerances, temperature changes, or ground motion. The coupling uses three ball-cone constraints, each combined with a released flexural degree of freedom. This arrangement enables a gain of higher load capacity and stiffness, but can also significantly reduce the friction level in proportion to the ball radius divided by the distance between the ball and the hinge axis. The blade flexures reduces somewhat the stiffness of the coupling and provides an ideal location to apply constrained-layer damping which is accomplished by attaching a viscoelastic layer and a constraining layer on opposite sides of each of the blade flexures. The three identical ball-cone flexures provide a damped coupling mechanism to kinematically support the projection optics system of the extreme ultraviolet lithography (EUVL) system, or other load-sensitive apparatus.

Program for impact testing of spar-shell fan blades, test report

NASA Technical Reports Server (NTRS)

Ravenhall, R.; Salemme, C. T.

1978-01-01

Six filament-wound, composite spar-shell fan blades were impact tested in a whirligig relative to foreign object damage resulting from ingestion of birds into the fan blades of a QCSEE-type engine. Four of the blades were tested by injecting a simulated two pound bird into the path of the rotating blade and two were tested by injecting a starling into the path of the blade.

PZT Active Frequency Based Wind Blade Fatigue to Failure Testing Results for Various Blade Designs

DTIC Science & Technology

2011-09-01

PZT Active Frequency Based Wind Blade Fatigue to Failure Testing Results for Various Blade Designs R. J. WERLINK...number. 1. REPORT DATE SEP 2011 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE PZT Active Frequency Based Wind Blade Fatigue ...18 Abstract: This paper summarizes NASA PZT Health Monitoring System results previously reported for 9 meter blade Fatigue loading to failure

UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction

PubMed Central

Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej; Eggers, Patrick C. F.; Olesen, Kim; Byskov, Claus; Pedersen, Gert Frølund

2015-01-01

A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1–5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally. PMID:26274964

Examination of the collision force method for analyzing the responses of simple containment/deflection structures to impact by one engine rotor blade fragment

NASA Technical Reports Server (NTRS)

Zirin, R. M.; Witmer, E. A.

1972-01-01

An approximate collision analysis, termed the collision-force method, was developed for studying impact-interaction of an engine rotor blade fragment with an initially circular containment ring. This collision analysis utilizes basic mass, material property, geometry, and pre-impact velocity information for the fragment, together with any one of three postulated patterns of blade deformation behavior: (1) the elastic straight blade model, (2) the elastic-plastic straight shortening blade model, and (3) the elastic-plastic curling blade model. The collision-induced forces are used to predict the resulting motions of both the blade fragment and the containment ring. Containment ring transient responses are predicted by a finite element computer code which accommodates the large deformation, elastic-plastic planar deformation behavior of simple structures such as beams and/or rings. The effects of varying the values of certain parameters in each blade-behavior model were studied. Comparisons of predictions with experimental data indicate that of the three postulated blade-behavior models, the elastic-plastic curling blade model appears to be the most plausible and satisfactory for predicting the impact-induced motions of a ductile engine rotor blade and a containment ring against which the blade impacts.

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 2: 50% Impartitioned Blades

NASA Technical Reports Server (NTRS)

Perkins, Porter J.; Mulholland, Donald R.

1948-01-01

The icing protection afforded an internal air-heated propeller blade by radial partitioning at 50-percent chord to confine the heated air to the forward half of the blade was determined in the NACA Cleveland icing research tunnel. A modified production-model hollow steel propeller, was used for the investigation. Temperatures of the blade surfaces for several heating rates were measured under various tunnel Icing' conditions. Photographic observations of ice formations on blade surfaces and blade heat-exchanger effectiveness were obtained. With 50-percent partitioning of the blades, adequate icing protection at 1050 rpm was obtained with a heating rate of 26,000 Btu per hour per blade at the blade shank using an air temperature of 400 F with a flow rate of 280 pounds per hour per blade, which is one-third less heat than was found necessary for similar Ice protection with unpartitioned blades. The chordwise distribution of the applied heat, as determined by surface temperature measurements, was considered unsatisfactory with much of the heat dissipated well back of the leading edge. Heat-exchanger effectiveness of approximately 56 percent also Indicated poor utilization of available heat. This effectiveness was, however, 9 percent greater than that obtained from unpartitioned blades.

A new universal laryngoscope blade: a preliminary comparison with Macintosh laryngoscope blades.

PubMed

Gerlach, Klaus; Wenzel, Volker; von Knobelsdorff, Georg; Steinfath, Markus; Dörges, Volker

2003-04-01

The Dörges universal laryngoscope blade has several features designed to facilitate tracheal intubation. The number of laryngoscope blades may be reduced from four to two, or even one, which indicate less space requirement and costs. This new universal laryngoscope blade, has a lower profile (height 15 vs. 22 mm) than a Macintosh laryngoscope blade size 3 and 4, which may facilitate manoeuvring of the laryngoscope in the mouth. In random order, 40 non-anaesthesia senior house officers used a Macintosh laryngoscope blade size 3 or 4 in an adult airway management trainer, a Macintosh laryngoscope blade size 2 in a paediatric airway management trainer, and the Dörges universal laryngoscope blade for both airway management trainers to perform orotracheal intubation. The number of intubation attempts and failures was counted. Participants reported the laryngoscopic view according to Cormack and Lehane. The time from touching the laryngoscope to the first adequate lung insufflation was measured, and subjective assessment regarding handling of both blades was recorded. Number of intubation failures, the laryngoscopic view according to Cormack and Lehane, and subjective assessment was comparable between groups. Orotracheal intubation of the adult airway management trainer with the Dörges universal laryngoscope blade took significantly less time compared to the Macintosh laryngoscope blades (14 (7-57) vs. 20 (8-43) s; P<0.001); all other intubating times were comparable. In conclusion, in this model, the Dörges universal laryngoscope blade was comparable to the Macintosh laryngoscope blades size 2-4, and may save time, cost and space.

The performance & flow visualization studies of three-dimensional (3-D) wind turbine blade models

NASA Astrophysics Data System (ADS)

Sutrisno, Prajitno, Purnomo, W., Setyawan B.

2016-06-01

Recently, studies on the design of 3-D wind turbine blades have a less attention even though 3-D blade products are widely sold. In contrary, advanced studies in 3-D helicopter blade tip have been studied rigorously. Studies in wind turbine blade modeling are mostly assumed that blade spanwise sections behave as independent two-dimensional airfoils, implying that there is no exchange of momentum in the spanwise direction. Moreover, flow visualization experiments are infrequently conducted. Therefore, a modeling study of wind turbine blade with visualization experiment is needed to be improved to obtain a better understanding. The purpose of this study is to investigate the performance of 3-D wind turbine blade models with backward-forward swept and verify the flow patterns using flow visualization. In this research, the blade models are constructed based on the twist and chord distributions following Schmitz's formula. Forward and backward swept are added to the rotating blades. Based on this, the additional swept would enhance or diminish outward flow disturbance or stall development propagation on the spanwise blade surfaces to give better blade design. Some combinations, i. e., b lades with backward swept, provide a better 3-D favorable rotational force of the rotor system. The performance of the 3-D wind turbine system model is measured by a torque meter, employing Prony's braking system. Furthermore, the 3-D flow patterns around the rotating blade models are investigated by applying "tuft-visualization technique", to study the appearance of laminar, separated, and boundary layer flow patterns surrounding the 3-dimentional blade system.

Full-field inspection of a wind turbine blade using three-dimensional digital image correlation

NASA Astrophysics Data System (ADS)

LeBlanc, Bruce; Niezrecki, Christopher; Avitabile, Peter; Chen, Julie; Sherwood, James; Hughes, Scott

2011-04-01

Increasing demand and deployment of wind power has led to a significant increase in the number of wind-turbine blades manufactured globally. As the physical size and number of turbines deployed grows, the probability of manufacturing defects being present in composite turbine blade fleets also increases. As both capital blade costs, and operational and maintenance costs, increase for larger turbine systems the need for large-scale inspection and monitoring of the state of structural health of turbine blades during manufacturing and operation critically increase. One method for locating and quantifying manufacturing defects, while also allowing for the in-situ measurement of the structural health of blades, is through the observation of the full-field state of deformation and strain of the blade. Static tests were performed on a nine-meter CX-100 composite turbine blade to extract full-field displacement and strain measurements using threedimensional digital image correlation (3D DIC). Measurements were taken at several angles near the blade root, including along the high-pressure surface, low-pressure surface, and along the trailing edge of the blade. The overall results indicate that the measurement approach can clearly identify failure locations and discontinuities in the blade curvature under load. Post-processing of the data using a stitching technique enables the shape and curvature of the entire blade to be observed for a large-scale wind turbine blade for the first time. The experiment demonstrates the feasibility of the approach and reveals that the technique readily can be scaled up to accommodate utility-scale blades. As long as a trackable pattern is applied to the surface of the blade, measurements can be made in-situ when a blade is on a manufacturing floor, installed in a test fixture, or installed on a rotating turbine. The results demonstrate the great potential of the optical measurement technique and its capability for use in the wind industry for large-area inspection.

Wooden wind turbine blade manufacturing process

DOEpatents

Coleman, Clint

1986-01-01

A wooden wind turbine blade is formed by laminating wood veneer in a compression mold having the exact curvature needed for one side of the blade, following which the other side of the blade is ground flat along its length but twisted with respect to the blade axis.

Method of making a wooden wind turbine blade

DOEpatents

Coleman, Clint

1984-01-01

A wooden wind turbine blade is formed by laminating wood veneer in a compression mold having the exact curvature needed for one side of the blade, following which the other side of the blade is ground flat along its length but twisted with respect to the blade axis.

Method of making a wooden wind turbine blade

DOEpatents

Coleman, C.

1984-08-14

A wooden wind turbine blade is formed by laminating wood veneer in a compression mold having the exact curvature needed for one side of the blade, following which the other side of the blade is ground flat along its length but twisted with respect to the blade axis. 8 figs.

Documentation of Helicopter Aeroelastic Stability Analysis Computer Program (HASTA)

DTIC Science & Technology

1977-12-01

of the blade phasing assumption for which all blades of the rotor are identical and equally spaced azimuthally allows the size of the T. matrices...to be significantly reduced by the removal of the submatrices associated with blades other than the first blade. With the use of this assumption ...different program representational options such as the type of rotor system, the type of blades, and the use of the blade phasing assumption , the

The Cooling of Turbine Blades,

DTIC Science & Technology

1981-06-11

aviation gas turbine engine , everyone has ceaselessly come up with ways of raising the temperature of gases in a turbine before combustion. The reason for...temperature of the blade concerned by approximately 200 degrees. Jet -type cooling. When the surface of a turbine blade is at a temperature which is...the blade and multiplying the drop in the temperature of the blade . Figure 3 is a cross-section diagram of a turbine blade cooled by the jet

Highly loaded multi-stage fan drive turbine-tandem blade configuration design

NASA Technical Reports Server (NTRS)

Evans, D. C.; Wolfmeyer, G. W.

1972-01-01

The results of the tandem blade configuration design study are reported. The three stage constant-inside-diameter turbine utilizes tandem blading in the stage two and stage three vanes and in the stage three blades. All other bladerows use plain blades. Blading detailed design is discussed, and design data are summarized. Steady-state stresses and vibratory behavior are discussed, and the results of the mechanical design analysis are presented.

Fabrication of composite propfan blades for a cruise missile wind tunnel model

NASA Technical Reports Server (NTRS)

Fite, E. Brian

1993-01-01

This report outlines the procedures that were employed in fabricating prototype graphite-epoxy composite prop fan blades. These blades were used in wind tunnel tests that investigated prop fan propulsion system interactions with a missile airframe in order to study the feasibility of an advanced-technology-propfan-propelled missile. Major phases of the blade fabrication presented include machining of the master blade, mold fabrication, ply cutting and assembly, blade curing, and quality assurance. Specifically, four separate designs were fabricated, 18 blades of each geometry, using the same fabrication technique for each design.

Bird impact analysis package for turbine engine fan blades

NASA Technical Reports Server (NTRS)

Hirschbein, M. S.

1982-01-01

A computer program has been developed to analyze the gross structural response of turbine engine fan blades subjected to bird strikes. The program couples a NASTRAN finite element model and modal analysis of a fan blade with a multi-mode bird impact analysis computer program. The impact analysis uses the NASTRAN blade model and a fluid jet model of the bird to interactively calculate blade loading during a bird strike event. The analysis package is computationaly efficient, easy to use and provides a comprehensive history of the gross structual blade response. Example cases are presented for a representative fan blade.

Design of impact-resistant boron/aluminum large fan blade

NASA Technical Reports Server (NTRS)

Salemme, C. T.; Yokel, S. A.

1978-01-01

The technical program was comprised of two technical tasks. Task 1 encompassed the preliminary boron/aluminum fan blade design effort. Two preliminary designs were evolved. An initial design consisted of 32 blades per stage and was based on material properties extracted from manufactured blades. A final design of 36 blades per stage was based on rule-of-mixture material properties. In Task 2, the selected preliminary blade design was refined via more sophisticated analytical tools. Detailed finite element stress analysis and aero performance analysis were carried out to determine blade material frequencies and directional stresses.

Successful Solutions to SSME/AT Development Turbine Blade Distress

NASA Technical Reports Server (NTRS)

Montgomery, Stuart K.

1999-01-01

As part of the High-Pressure Fuel Turbopump/Alternate Turbopump (HPFTP/AT) turbine blade development program, unique turbine blade design features were implemented to address 2nd stage turbine blade high cycle fatigue distress and improve turbine robustness. Features included the addition of platform featherseal dampers, asymmetric blade tip seal segments, gold plating of the blade attachments, and airfoil tip trailing edge modifications. Development testing shows these features have eliminated turbine blade high cycle fatigue distress and consequently these features are currently planned for incorporation to the flight configuration. Certification testing will begin in 1999. This presentation summarizes these features.

BLADED IMPELLER FOR TURBOBLOWERS

DOEpatents

Baumann, K.

1949-10-01

A means is given of holding open-sided impeller blades in a turbo-rotor. Two half blades, with dovetail roots of sufficient weight to contain the center of gravity, are fitted into slots cut in the rotor so as to form the desired angle between the blade faces. The adjoining edges of the half blades are welded to form one solid blade that is securely locked an the rotor. This design permits the manufacture of a V shaped impeller blade without the need of machining the entire V shaped contour from a single blank, and furthermore provides excellent locking characteristics for attachment to the rotor.

Computer program for definition of transonic axial-flow compressor blade rows. [computer program for fabrication and aeroelastic analysis

NASA Technical Reports Server (NTRS)

Crouse, J. E.

1974-01-01

A method is presented for designing axial-flow compressor blading from blade elements defined on cones which pass through the blade-edge streamline locations. Each blade-element centerline is composed of two segments which are tangent to each other. The centerline and surfaces of each segment have constant change of angle with path distance. The stacking line for the blade elements can be leaned in both the axial and tangential directions. The output of the computer program gives coordinates for fabrication and properties for aeroelastic analysis for planar blade sections. These coordinates and properties are obtained by interpolation across conical blade elements. The program is structured to be coupled with an aerodynamic design program.

Studies of blade-vortex interaction noise reduction by rotor blade modification

NASA Technical Reports Server (NTRS)

Brooks, Thomas F.

1993-01-01

Blade-vortex interaction (BVI) noise is one of the most objectionable types of helicopter noise. This impulsive blade-slap noise can be particularly intense during low-speed landing approach and maneuvers. Over the years, a number of flight and model rotor tests have examined blade tip modification and other blade design changes to reduce this noise. Many times these tests have produced conflicting results. In the present paper, a number of these studies are reviewed in light of the current understanding of the BVI noise problem. Results from one study in particular are used to help establish the noise reduction potential and to shed light on the role of blade design. Current blade studies and some new concepts under development are also described.

Construction of low-cost, Mod-OA wood composite wind turbine blades

NASA Technical Reports Server (NTRS)

Lark, R. F.

1983-01-01

Two sixty-foot, low-cost, wood composite blades for service on 200 kW Mod-OA wind turbines were constructed. The blades were constructed of epoxy resin-bonded Douglas fir veneers for the leading edge sections, and paper honeycombcored, birch plywood faced panels for the afterbody sections. The blades were joined to the wind turbine hub by epoxy resin-bonded steel load take-off studs embedded into the root end of the blades. The blades were installed on the 200 kW Mod-OA wind turbine facility at Kahuku, Hawaii, The blades completed nearly 8,000 hours of operation over an 18 month period at an average power of 150 kW prior to replacement with another set of wood composite blades. The blades were replaced because of a corrosion failure of the steel shank on one stud. Inspections showed that the wood composite structure remained in excellent condition.

Retention system and method for the blades of a rotary machine

DOEpatents

Pedersen, Poul D.; Glynn, Christopher C.; Walker, Roger C.

2002-01-01

A retention system and method for the blades of a rotary machine for preventing forward or aft axial movement of the rotor blades includes a circumferential hub slot formed about a circumference of the machine hub. The rotor blades have machined therein a blade retention slot which is aligned with the circumferential hub slot when the blades are received in correspondingly shaped openings in the hub. At least one ring segment is secured in the blade retention slots and the circumferential hub slot to retain the blades from axial movement. A key assembly is used to secure the ring segments in the aligned slots via a hook portion receiving the ring segments and a threaded portion that is driven radially outwardly by a nut. A cap may be provided to provide a redundant back-up load path for the centrifugal loads on the key. Alternatively, the key assembly may be formed in the blade dovetail.

Surface modeling method for aircraft engine blades by using speckle patterns based on the virtual stereo vision system

NASA Astrophysics Data System (ADS)

Yu, Zhijing; Ma, Kai; Wang, Zhijun; Wu, Jun; Wang, Tao; Zhuge, Jingchang

2018-03-01

A blade is one of the most important components of an aircraft engine. Due to its high manufacturing costs, it is indispensable to come up with methods for repairing damaged blades. In order to obtain a surface model of the blades, this paper proposes a modeling method by using speckle patterns based on the virtual stereo vision system. Firstly, blades are sprayed evenly creating random speckle patterns and point clouds from blade surfaces can be calculated by using speckle patterns based on the virtual stereo vision system. Secondly, boundary points are obtained in the way of varied step lengths according to curvature and are fitted to get a blade surface envelope with a cubic B-spline curve. Finally, the surface model of blades is established with the envelope curves and the point clouds. Experimental results show that the surface model of aircraft engine blades is fair and accurate.

Development of an Active Twist Rotor for Wind: Tunnel Testing (NLPN97-310

NASA Technical Reports Server (NTRS)

Cesnik, Carlos E. S.; Shin, SangJoon; Hagood, Nesbitt W., IV

1998-01-01

The development of the Active Twist Rotor prototype blade for hub vibration and noise reduction studies is presented in this report. Details of the modeling, design, and manufacturing are explored. The rotor blade is integrally twisted by direct strain actuation. This is accomplished by distributing embedded piezoelectric fiber composites along the span of the blade. The development of the analysis framework for this type of active blade is presented. The requirements for the prototype blade, along with the final design results are also presented. A detail discussion on the manufacturing aspects of the prototype blade is described. Experimental structural characteristics of the prototype blade compare well with design goals, and preliminary bench actuation tests show lower performance than originally predicted. Electrical difficulties with the actuators are also discussed. The presented prototype blade is leading to a complete fully articulated four-blade active twist rotor system for future wind tunnel tests.

Study on the Pressure Pulsation inside Runner with Splitter Blades in Ultra-High Head Turbine

NASA Astrophysics Data System (ADS)

Meng, L.; Zhang, S. P.; Zhou, L. J.; Wang, Z. W.

2014-03-01

Runners with splitter blades were used widely for the high efficiency and stability. In this paper, the unsteady simulation of an ultra-high head turbine at the best efficiency point, 50% and 75% discharge points were established, to analyze the pressure pulsation in the vaneless space, rotating domain and the draft tube. First of all, runners with different length splitter blades and without splitter blades were compared to learn the efficiency and the pressure distribution on the blade surface. And then the amplitude of the pressure pulsation was analysed. The peak efficiency of the runner with splitter blades is remarkably higher than that of the corresponding impeller without splitter blades. And the efficiency of the turbine is the highest when the length ratio of the splitter blades is 0.75 times the main blades. The pressure pulsation characteristics were also influenced, because the amplitudes of the pulsation induced by the RSI phenomenon were changed as a result of more blades. At last, the best design plan of the length of the splitter blades (length ratio=0.825) was obtained, which improved the pressure pulsation characteristics without significant prejudice to the efficiency.

Design and Test Research on Cutting Blade of Corn Harvester Based on Bionic Principle.

PubMed

Tian, Kunpeng; Li, Xianwang; Zhang, Bin; Chen, Qiaomin; Shen, Cheng; Huang, Jicheng

2017-01-01

Existing corn harvester cutting blades have problems associated with large cutting resistance, high energy consumption, and poor cut quality. Using bionics principles, a bionic blade was designed by extracting the cutting tooth profile curve of the B. horsfieldi palate. Using a double-blade cutting device testing system, a single stalk cutting performance contrast test for corn stalks obtained at harvest time was carried out. Results show that bionic blades have superior performance, demonstrated by strong cutting ability and good cut quality. Using statistical analysis of two groups of cutting test data, the average cutting force and cutting energy of bionic blades and ordinary blades were obtained as 480.24 N and 551.31 N and 3.91 J and 4.38 J, respectively. Average maximum cutting force and cutting energy consumption for the bionic blade were reduced by 12.89% and 10.73%, respectively. Variance analysis showed that both blade types had a significant effect on maximum cutting energy and cutting energy required to cut a corn stalk. This demonstrates that bionic blades have better cutting force and energy consumption reduction performance than ordinary blades.

Analytical study on different blade-shape design of HAWT for wasted kinetic energy recovery system (WKERS)

NASA Astrophysics Data System (ADS)

Goh, J. B.; Jamaludin, Z.; Jafar, F. A.; Mat Ali, M.; Mokhtar, M. N. Ali; Tan, C. H.

2017-06-01

Wasted kinetic energy recovery system (WKERS) is a wind renewable gadget installed above a cooling tower outlet to harvest the discharged wind for electrical regeneration purpose. The previous WKERS is operated by a horizontal axis wind turbine (HAWT) with delta blade design but the performance is still not at the optimum level. Perhaps, a better blade-shape design should be determined to obtain the optimal performance, as it is believed that the blade-shape design plays a critical role in HAWT. Hence, to determine a better blade-shape design for a new generation of WKERS, elliptical blade, swept blade and NREL Phase IV blade are selected for this benchmarking process. NREL Phase IV blade is a modern HAWT’s blade design by National Renewable Energy Laboratory (NREL) research lab. During the process of benchmarking, Computational Fluid Dynamics (CFD) analysis was ran by using SolidWorks design software, where all the designs are simulated with linear flow simulation. The wind speed in the simulation is set at 10.0 m/s, which is compatible with the average wind speed produced by a standard size cooling tower. The result is obtained by flow trajectories of air motion, surface plot and cut plot of the applied blade-shape. Besides, the aspect ratio of each blade is calculated and included as one of the reference in the comparison. Hence, the final selection of the best blade-shape design will bring to the new generation of WKERS.

Numerical investigations on axial and radial blade rubs in turbo-machinery

NASA Astrophysics Data System (ADS)

Abdelrhman, Ahmed M.; Tang, Eric Sang Sung; Salman Leong, M.; Al-Qrimli, Haidar F.; Rajamohan, G.

2017-07-01

In the recent years, the clearance between the rotor blades and stator/casing had been getting smaller and smaller prior improving the aerodynamic efficiency of the turbomachines as demand in the engineering field. Due to the clearance reduction between the blade tip and the rotor casing and between rotor blades and stator blades, axial and radial blade rubbing could be occurred, especially at high speed resulting into complex nonlinear vibrations. The primary aim of this study is to address the blade axial rubbing phenomenon using numerical analysis of rotor system. A comparison between rubbing caused impacts of axial and radial blade rubbing and rubbing forces are also aims of this study. Tow rotor models (rotor-stator and rotor casing models) has been designed and sketched using SOILDSWORKS software. ANSYS software has been used for the simulation and the numerical analysis. The rubbing conditions were simulated at speed range of 1000rpm, 1500rpm and 2000rpm. Analysis results for axial blade rubbing showed the appearance of blade passing frequency and its multiple frequencies (lx, 2x 3x etc.) and these frequencies will more excited with increasing the rotational speed. Also, it has been observed that when the rotating speed increased, the rubbing force and the harmonics frequencies in x, y and z-direction become higher and severe. The comparison study showed that axial blade rub is more dangerous and would generate a higher vibration impacts and higher blade rubbing force than radial blade rub.

SSME HPFTP/AT Turbine Blade Platform Featherseal Damper Design

NASA Technical Reports Server (NTRS)

Montgomery, S. K.

1999-01-01

During the Space Shuttle Main Engines (SSM) HPFtP/AT development program, engine hot fire testing resulted in turbine blade fatigue cracks. The cracks were noted after only a few tests and a several hundred seconds versus the design goal of 60 tests and >30,000 seconds. Subsequent investigation attributed the distress to excessive steady and dynamic loads. To address these excessive turbine blade loads, Pratt & Whitney Liquid Space Propulsion engineers designed and developed retrofitable turbine blade to blade platform featherseal dampers. Since incorporation of these dampers, along with other turbine blade system improvements, there has been no observed SSME HPFTP/AT turbine blade fatigue cracking. The high time HPFTP/AT blade now has accumulated 32 starts and 19,200 seconds hot fire test time. Figure #1 illustrates the HPFTP/AT turbine blade platform featherseal dampers. The approached selected was to improve the turbine blade structural capability while simultaneously reducing loads. To achieve this goal, the featherseal dampers were designed to seal the blade to blade platform gap and damp the dynamic motions. Sealing improves the steady stress margins by increasing turbine efficiency and improving turbine blade attachment thermal conditioning. Load reduction was achieved through damping. Thin Haynes 188 sheet metal was selected based on its material properties (hydrogen resistance, elongation, tensile strengths, etc.). The 36,000 rpm wheel speed of the rotor result in a normal load of 120#/blade. The featherseals then act as micro-slip dampers during actual SSME operation. After initial design and analysis (prior to full engine testing), the featherseal dampers were tested in P&W's spin rig facility in West Palm Beach, Florida. Both dynamic strain gages and turbine blade tip displacement measurements were utilized to quantify the featherseal damper effectiveness. Full speed (36,000 rpm), room temperature rig testing verified the elimination of fundamental mode (i.e, modes 1 & 2) resonant response. The reduction in turbine blade dynamic response is shown for a typical turbine blade. This paper discusses the design and verification of these dampers. The numerous benefits associated with this design concept warrants consideration in existing and future turbomachinery applications.

Sustainable Mining Land Use for Lignite Based Energy Projects

NASA Astrophysics Data System (ADS)

Dudek, Michal; Krysa, Zbigniew

2017-12-01

This research aims to discuss complex lignite based energy projects economic viability and its impact on sustainable land use with respect to project risk and uncertainty, economics, optimisation (e.g. Lerchs and Grossmann) and importance of lignite as fuel that may be expressed in situ as deposit of energy. Sensitivity analysis and simulation consist of estimated variable land acquisition costs, geostatistics, 3D deposit block modelling, electricity price considered as project product price, power station efficiency and power station lignite processing unit cost, CO2 allowance costs, mining unit cost and also lignite availability treated as lignite reserves kriging estimation error. Investigated parameters have nonlinear influence on results so that economically viable amount of lignite in optimal pit varies having also nonlinear impact on land area required for mining operation.

Anisotropic piezoelectric twist actuation of helicopter rotor blades: Aeroelastic analysis and design optimization

NASA Astrophysics Data System (ADS)

Wilkie, William Keats

1997-12-01

An aeroelastic model suitable for control law and preliminary structural design of composite helicopter rotor blades incorporating embedded anisotropic piezoelectric actuator laminae is developed. The aeroelasticity model consists of a linear, nonuniform beam representation of the blade structure, including linear piezoelectric actuation terms, coupled with a nonlinear, finite-state unsteady aerodynamics model. A Galerkin procedure and numerical integration in the time domain are used to obtain a soluti An aeroelastic model suitable for control law and preliminary structural design of composite helicopter rotor blades incorporating embedded anisotropic piezoelectric actuator laminae is developed. The aeroelasticity model consists of a linear, nonuniform beam representation of the blade structure, including linear piezoelectric actuation terms, coupled with a nonlinear, finite-state unsteady aerodynamics model. A Galerkin procedure and numerical integration in the time domain are used to obtain amited additional piezoelectric material mass, it is shown that blade twist actuation approaches which exploit in-plane piezoelectric free-stain anisotropies are capable of producing amplitudes of oscillatory blade twisting sufficient for rotor vibration reduction applications. The second study examines the effectiveness of using embedded piezoelectric actuator laminae to alleviate vibratory loads due to retreating blade stall. A 10 to 15 percent improvement in dynamic stall limited forward flight speed, and a 5 percent improvement in stall limited rotor thrust were numerically demonstrated for the active twist rotor blade relative to a conventional blade design. The active twist blades are also demonstrated to be more susceptible than the conventional blades to dynamic stall induced vibratory loads when not operating with twist actuation. This is the result of designing the active twist blades with low torsional stiffness in order to maximize piezoelectric twist authority. Determining the optimum tradeoff between blade torsional stiffness and piezoelectric twist actuation authority is the subject of the third study. For this investigation, a linearized hovering-flight eigenvalue analysis is developed. Linear optimal control theory is then utilized to develop an optimum active twist blade design in terms of reducing structural energy and control effort cost. The forward flight vibratory loads characteristics of the torsional stiffness optimized active twist blade are then examined using the nonlinear, forward flight aeroelastic analysis. The optimized active twist rotor blade is shown to have improved passive and active vibratory loads characteristics relative to the baseline active twist blades.

Effect of Variable Chord Length on Transonic Axial Rotor Performance Investigated

NASA Technical Reports Server (NTRS)

Suder, Kenneth L.

2002-01-01

During the life of any gas turbine, blade erosion is present, especially for those units that are exposed to unfiltered air, such as aviation turbofan engines. The effect of this erosion is to reduce the blade chord progressively from the midspan to the tip region and to roughen and distort the blade surface. The effects of roughness on rotor performance have been documented by Suder et al. and Roberts. These papers indicate that the penalty for leading-edge roughness and erosion can be significant. Turbofan operators, therefore, restore chord length at routine maintenance intervals to regain performance before deterioration is too severe to salvage blades. As the rotor blades erode, the leading edge becomes rough - blunt and distorted from the nominal shape - and the aerodynamic performance suffers. Nominal performance can be recovered by recontouring the leading edges. This process, which inherently shortens the blade chord, can be used until the blade chord erodes to the stall limit. Below this chord length, which varies among engine-compressor types, a decrease of stall margin is likely. After compressor blade rework that includes leading edge recontouring, the blades have different chord lengths, ranging from blades that are near nominal chord length down to those near the stall chord limit. Furthermore, as blades erode below the stall limit, they must be replaced with new blades that have the full nominal chord length. Consequently, a set of compressor blades with varying chord lengths will be installed into each turbofan engine that goes through a complete maintenance cycle. The question arises, "Does fan or compressor performance depend on the order in which mixed-chord blades are installed into a fan or compressor disk?"

Pin and roller attachment system for ceramic blades

DOEpatents

Shaffer, James E.

1995-01-01

In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints.

Determination of Turbine Blade Life from Engine Field Data

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

2013-01-01

It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal-mechanical fatigue (TMF) as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) TMF, (2) Oxidation/erosion (O/E), and (3) Other. From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L10 blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to O/E equaled that attributed to TMF. The category that contributed most to blade failure was Other. If there were no blade failures attributed to O/E and TMF, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

Design, evaluation, and fabrication of low-cost composite blades for intermediate-size wind turbines

NASA Technical Reports Server (NTRS)

Weingart, O.

1981-01-01

Low cost approaches for production of 60 ft long glass fiber/resin composite rotor blades for the MOD-OA wind turbine were identified and evaluated. The most cost-effective configuration was selected for detailed design. Subelement and subscale specimens were fabricated for testing to confirm physical and mechanical properties of the composite blade materials, to develop and evaluate blade fabrication techniques and processes, and to confirm the structural adequacy of the root end joint. Full-scale blade tooling was constructed and a partial blade for tool and process tryout was built. Then two full scale blades were fabricated and delivered to NASA-LeRC for installation on a MOD-OA wind turbine at Clayton, New Mexico for operational testing. Each blade was 60 ft. long with 4.5 ft. chord at root end and 2575 lbs weight including metal hub adapter. The selected blade configuration was a three cell design constructed using a resin impregnated glass fiber tape winding process that allows rapid wrapping of primarily axially oriented fibers onto a tapered mandrel, with tapered wall thickness. The ring winder/transverse filament tape process combination was used for the first time on this program to produce entire rotor blade structures. This approach permitted the complete blade to be wound on stationary mandrels, an improvement which alleviated some of the tooling and process problems encountered on previous composite blade programs.

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR § 1205.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

Apparatus for loading a band saw blade

DOEpatents

Reeves, Steven R.

1990-01-01

A band saw blade is loaded between pairs of guide wheels upon tensioning the blade by guiding the blade between pairs of spaced guide plates which define converging slots that converge toward the guide wheels. The approach is particularly useful in loading blades on underwater band saw machines used to cut radioactive materials.

Design, Test, and Evaluation of a Transonic Axial Compressor Rotor with Splitter Blades

DTIC Science & Technology

2013-09-01

parameters .......................................................17 Figure 13. Third-order spline fit for blade camber line distribution...18 Figure 14. Third-order spline fit for blade thickness distribution .....................................19 Figure 15. Blade...leading edge: third-order spline fit for thickness distribution ...............20 Figure 16. Blade leading edge and trailing edge slope blending

Fiber composite fan blade impact improvement

NASA Technical Reports Server (NTRS)

Graff, J.; Stoltze, L.; Varholak, E. M.

1976-01-01

The improved foreign object damage resistance of a metal matrix advanced composite fan blade was demonstrated. The fabrication, whirl impact test and subsequent evaluation of nine advanced composite fan blades of the "QCSEE" type design were performed. The blades were designed to operate at a tip speed of 282 m/sec. The blade design was the spar/shell type, consisting of a titanium spar and boron/aluminum composite airfoils. The blade retention was designed to rock on impact with large birds, thereby reducing the blade bending stresses. The program demonstrated the ability of the blades to sustain impacts with up to 681 g slices of birds at 0.38 rad with little damage (only 1.4 percent max weight loss) and 788 g slices of birds at 0.56 rad with only 3.2 percent max weight loss. Unbonding did not exceed 1.1 percent of the post-test blade area during any of the tests. All blades in the post-test condition were judged capable of operation in accordance with the FAA guidelines for medium and large bird impacts.

On the Cutting Performance of Segmented Diamond Blades when Dry-Cutting Concrete

PubMed Central

Martynenko, V.; Martínez Krahmer, D.; Benítez, A.; Genovese, G.

2018-01-01

The objective of the present study is to analyze and compare the cutting performance of segmented diamond blades when dry-cutting concrete. A cutting criteria is proposed to characterize the wear of the blades by measuring the variation of the external diameter and the weight loss of the blade. The results exhibit the cutting blade SB-A, which has twice the density of diamonds and large contact area, exhibits less wear even though the material removal rate is higher compared with the other two cutting blades. Additionally, the surface topography of the different blades is evaluated to examine the impact of wear depending on the surface profile and the distribution of the diamonds in the blade’s matrix. Large number of diamonds pull-out are found in blades type SB-C, which additionally shows the worst wear resistant capability. As a conclusion, the cutting efficiency of the blade is found to be related to the density of embedded diamonds and the type of the surface profile of the cutting blade after reaching the stop criteria. PMID:29425125

Experimental impact testing and analysis of composite fan cases

NASA Astrophysics Data System (ADS)

Vander Klok, Andrew Joe

For aircraft engine certification, one of the requirements is to demonstrate the ability of the engine to withstand a fan blade-out (FBO) event. A FBO event may be caused by fatigue failure of the fan blade itself or by impact damage of foreign objects such as bird strike. An un-contained blade can damage flight critical engine components or even the fuselage. The design of a containment structure is related to numerous parameters such as the blade tip speed; blade material, size and shape; hub/tip diameter; fan case material, configuration, rigidity, etc. To investigate all parameters by spin experiments with a full size rotor assembly can be prohibitively expensive. Gas gun experiments can generate useful data for the design of engine containment cases at much lower costs. To replicate the damage modes similar to that on a fan case in FBO testing, the gas gun experiment has to be carefully designed. To investigate the experimental procedure and data acquisition techniques for FBO test, a low cost, small spin rig was first constructed. FBO tests were carried out with the small rig. The observed blade-to-fan case interactions were similar to those reported using larger spin rigs. The small rig has the potential in a variety of applications from investigating FBO events, verifying concept designs of rotors, to developing spin testing techniques. This rig was used in the developments of the notched blade releasing mechanism, a wire trigger method for synchronized data acquisition, high speed video imaging and etc. A relationship between the notch depth and the release speed was developed and verified. Next, an original custom designed spin testing facility was constructed. Driven by a 40HP, 40,000rpm air turbine, the spin rig is housed in a vacuum chamber of phi72inx40in (1829mmx1016mm). The heavily armored chamber is furnished with 9 viewports. This facility enables unprecedented investigations of FBO events. In parallel, a 15.4ft (4.7m) long phi4.1inch (105mm) diameter single stage gas gun was developed. A thermodynamic based relationship between the required gas pressure and targeted velocity was proposed. The predicted velocity was within +/-7%. Quantitative measurements of force and displacement were attempted. The transmitted impact force was measured with load cells. The out-of-plane deformation was measured with a projection grating profilometry method. The composite panels and fan cases used in this work were made of S2-glass plain weave fabrics with API SC-15 toughened epoxy resin using the vacuum assisted resin transfer molding (VARTM) method. Using the gas gun, the impact behavior of the composite was investigated at velocities ranging from 984ft/s to 1502ft/s (300m/s to 458m/s) following a draft ASTM testing standard. To compare the ballistic protection capability of different materials, a new parameter EBL, the projectile kinetic energy at the target ballistic limit normalized by the contact area of the projectile, was proposed. S2-glass/epoxy composite is ranked very high in EBL per areal weight. Finally, a testing method for replicating spin pit testing with a gas gun test was developed. Major differences between the two tests are the initial conditions of the blade upon contact with the target. In spin testing, the released blade has two velocity components, rotational and translational whereas in gas gun testing, the projectile has only the translational velocity. To account for the influence of the rotational velocity, three projectile designs were experimentally investigated. The results show that to generate similar damage modes in gas gun testing, it is critical to ensure the deformation of the projectile before testing is similar to that of a released blade. With the pre-bent blade, the gas gun experiment was able to replicate the damage modes of the fan case in FBO test on flat composite panels.

Coupled Aerodynamic-Thermal-Structural (CATS) Analysis

NASA Technical Reports Server (NTRS)

1995-01-01

Coupled Aerodynamic-Thermal-Structural (CATS) Analysis is a focused effort within the Numerical Propulsion System Simulation (NPSS) program to streamline multidisciplinary analysis of aeropropulsion components and assemblies. Multidisciplinary analysis of axial-flow compressor performance has been selected for the initial focus of this project. CATS will permit more accurate compressor system analysis by enabling users to include thermal and mechanical effects as an integral part of the aerodynamic analysis of the compressor primary flowpath. Thus, critical details, such as the variation of blade tip clearances and the deformation of the flowpath geometry, can be more accurately modeled and included in the aerodynamic analyses. The benefits of this coupled analysis capability are (1) performance and stall line predictions are improved by the inclusion of tip clearances and hot geometries, (2) design alternatives can be readily analyzed, and (3) higher fidelity analysis by researchers in various disciplines is possible. The goals for this project are a 10-percent improvement in stall margin predictions and a 2:1 speed-up in multidisciplinary analysis times. Working cooperatively with Pratt & Whitney, the Lewis CATS team defined the engineering processes and identified the software products necessary for streamlining these processes. The basic approach is to integrate the aerodynamic, thermal, and structural computational analyses by using data management and Non-Uniform Rational B-Splines (NURBS) based data mapping. Five software products have been defined for this task: (1) a primary flowpath data mapper, (2) a two-dimensional data mapper, (3) a database interface, (4) a blade structural pre- and post-processor, and (5) a computational fluid dynamics code for aerothermal analysis of the drum rotor. Thus far (1) a cooperative agreement has been established with Pratt & Whitney, (2) a Primary Flowpath Data Mapper has been prototyped and delivered to General Electric Aircraft Engines and Pratt & Whitney for evaluation, (3) a collaborative effort has been initiated with the National Institute of Standards and Testing to develop a Standard Data Access Interface, and (4) a blade tip clearance capability has been implemented into the Structural Airfoil Blade Engineering Routine (SABER) program. We plan to continue to develop the data mappers and data management tools. As progress is made, additional efforts will be made to apply these tools to propulsion system applications.

Rotor Hover Performance and Flowfield Measurements with Untwisted and Highly-Twisted Blades

NASA Technical Reports Server (NTRS)

Ramasamy, Manikandan; Gold, Nili P.; Bhagwat, Mahendra J.

2010-01-01

The flowfield and performance characteristics of highly-twisted blades were analyzed at various thrust conditions to improve the fundamental understanding relating the wake effects on rotor performance. Similar measurements made using untwisted blades served as the baseline case. Twisted blades are known to give better hover performance than untwisted blades at high thrust coefficients typical of those found in full-scale rotors. However, the present experiments were conducted at sufficiently low thrust (beginning from zero thrust), where the untwisted blades showed identical, if not better, performance when compared with the highly-twisted blades. The flowfield measurements showed some key wake differences between the two rotors, as well. These observations when combined with simple blade element momentum theory (also called annular disk momentum theory) helped further the understanding of rotor performance characteristics.

Development of a turbomachinery design optimization procedure using a multiple-parameter nonlinear perturbation method

NASA Technical Reports Server (NTRS)

Stahara, S. S.

1984-01-01

An investigation was carried out to complete the preliminary development of a combined perturbation/optimization procedure and associated computational code for designing optimized blade-to-blade profiles of turbomachinery blades. The overall purpose of the procedures developed is to provide demonstration of a rapid nonlinear perturbation method for minimizing the computational requirements associated with parametric design studies of turbomachinery flows. The method combines the multiple parameter nonlinear perturbation method, successfully developed in previous phases of this study, with the NASA TSONIC blade-to-blade turbomachinery flow solver, and the COPES-CONMIN optimization procedure into a user's code for designing optimized blade-to-blade surface profiles of turbomachinery blades. Results of several design applications and a documented version of the code together with a user's manual are provided.

The multiple roles of computational chemistry in fragment-based drug design

NASA Astrophysics Data System (ADS)

Law, Richard; Barker, Oliver; Barker, John J.; Hesterkamp, Thomas; Godemann, Robert; Andersen, Ole; Fryatt, Tara; Courtney, Steve; Hallett, Dave; Whittaker, Mark

2009-08-01

Fragment-based drug discovery (FBDD) represents a change in strategy from the screening of molecules with higher molecular weights and physical properties more akin to fully drug-like compounds, to the screening of smaller, less complex molecules. This is because it has been recognised that fragment hit molecules can be efficiently grown and optimised into leads, particularly after the binding mode to the target protein has been first determined by 3D structural elucidation, e.g. by NMR or X-ray crystallography. Several studies have shown that medicinal chemistry optimisation of an already drug-like hit or lead compound can result in a final compound with too high molecular weight and lipophilicity. The evolution of a lower molecular weight fragment hit therefore represents an attractive alternative approach to optimisation as it allows better control of compound properties. Computational chemistry can play an important role both prior to a fragment screen, in producing a target focussed fragment library, and post-screening in the evolution of a drug-like molecule from a fragment hit, both with and without the available fragment-target co-complex structure. We will review many of the current developments in the area and illustrate with some recent examples from successful FBDD discovery projects that we have conducted.

A new paradigm in personal dosimetry using LiF:Mg,Cu,P.

PubMed

Cassata, J R; Moscovitch, M; Rotunda, J E; Velbeck, K J

2002-01-01

The United States Navy has been monitoring personnel for occupational exposure to ionising radiation since 1947. Film was exclusively used until 1973 when thermoluminescence dosemeters were introduced and used to the present time. In 1994, a joint research project between the Naval Dosimetry Center, Georgetown University, and Saint Gobain Crystals and Detectors (formerly Bicron RMP formerly Harshaw TLD) began to develop a state of the art thermoluminescent dosimetry system. The study was conducted from a large-scale dosimetry processor point of view with emphasis on a systems approach. Significant improvements were achieved by replacing the LiF:Mg,Ti with LiF:Mg,Cu,P TL elements due to the significant sensitivity increase, linearity, and negligible hiding. Dosemeter filters were optimised for gamma and X ray energy discrimination using Monte Carlo modelling (MCNP) resulting in significant improvement in accuracy and precision. Further improvements were achieved through the use of neural-network based dose calculation algorithms. Both back propagation and functional link methods were implemented and the data compared with essentially the same results. Several operational aspects of the system are discussed, including (1) background subtraction using control dosemeters, (2) selection criteria for control dosemeters, (3) optimisation of the TLD readers, (4) calibration methodology, and (5) the optimisation of the heating profile.

An Optimised System for Generating Multi-Resolution Dtms Using NASA Mro Datasets

NASA Astrophysics Data System (ADS)

Tao, Y.; Muller, J.-P.; Sidiropoulos, P.; Veitch-Michaelis, J.; Yershov, V.

2016-06-01

Within the EU FP-7 iMars project, a fully automated multi-resolution DTM processing chain, called Co-registration ASP-Gotcha Optimised (CASP-GO) has been developed, based on the open source NASA Ames Stereo Pipeline (ASP). CASP-GO includes tiepoint based multi-resolution image co-registration and an adaptive least squares correlation-based sub-pixel refinement method called Gotcha. The implemented system guarantees global geo-referencing compliance with respect to HRSC (and thence to MOLA), provides refined stereo matching completeness and accuracy based on the ASP normalised cross-correlation. We summarise issues discovered from experimenting with the use of the open-source ASP DTM processing chain and introduce our new working solutions. These issues include global co-registration accuracy, de-noising, dealing with failure in matching, matching confidence estimation, outlier definition and rejection scheme, various DTM artefacts, uncertainty estimation, and quality-efficiency trade-offs.

Fluid Mechanics Optimising Organic Synthesis

NASA Astrophysics Data System (ADS)

Leivadarou, Evgenia; Dalziel, Stuart

2015-11-01

The Vortex Fluidic Device (VFD) is a new ``green'' approach in the synthesis of organic chemicals with many industrial applications in biodiesel generation, cosmetics, protein folding and pharmaceutical production. The VFD is a rapidly rotating tube that can operate with a jet feeding drops of liquid reactants to the base of the tube. The aim of this project is to explain the fluid mechanics of the VFD that influence the rate of reactions. The reaction rate is intimately related to the intense shearing that promotes collision between reactant molecules. In the VFD, the highest shears are found at the bottom of the tube in the Rayleigh and the Ekman layer and at the walls in the Stewardson layers. As a step towards optimising the performance of the VFD we present experiments conducted in order to establish the minimum drop volume and maximum rotation rate for maximum axisymmetric spreading without fingering instability. PhD candidate, Department of Applied Mathematics and Theoretical Physics.

Hardware Design of the Energy Efficient Fall Detection Device

NASA Astrophysics Data System (ADS)

Skorodumovs, A.; Avots, E.; Hofmanis, J.; Korāts, G.

2016-04-01

Health issues for elderly people may lead to different injuries obtained during simple activities of daily living. Potentially the most dangerous are unintentional falls that may be critical or even lethal to some patients due to the heavy injury risk. In the project "Wireless Sensor Systems in Telecare Application for Elderly People", we have developed a robust fall detection algorithm for a wearable wireless sensor. To optimise the algorithm for hardware performance and test it in field, we have designed an accelerometer based wireless fall detector. Our main considerations were: a) functionality - so that the algorithm can be applied to the chosen hardware, and b) power efficiency - so that it can run for a very long time. We have picked and tested the parts, built a prototype, optimised the firmware for lowest consumption, tested the performance and measured the consumption parameters. In this paper, we discuss our design choices and present the results of our work.

Microcomputer monitor system and device for non-touch measurement of turbine blade vibration

NASA Astrophysics Data System (ADS)

Zheng, Shu-Chen; Liu, Bo; Qu, Zhi-Huan; Din, Ke-Ke

To study the aeroelastic phenomena in turbomachinery, a microcomputer monitor system and device for nonintrusive measurement of turbine blade vibration is developed. The system can continuously measure blade amplitude of vibration, phase angle, and torsional angle, when the machinery blades encounter vibration. In the case of turbine operation, it can display and print the vibrating parameters measured by the system, automatically give out the warning when blade amplitude of vibration is bigger than safety value, or blades break. The vibrating parameters in a span of time before the break occurs is recorded. A forecast is produced as blades enter the flutter boundary.

Estimating Blade Section Airloads from Blade Leading-Edge Pressure Measurements

NASA Technical Reports Server (NTRS)

vanAken, Johannes M.

2003-01-01

The Tilt-Rotor Aeroacoustic Model (TRAM) test in the Duitse-Nederlandse Wind (DNW) Tunnel acquired blade pressure data for forward flight test conditions of a tiltrotor in helicopter mode. Chordwise pressure data at seven radial locations were integrated to obtain the blade section normal force. The present investigation evaluates the use of linear regression analysis and of neural networks in estimating the blade section normal force coefficient from a limited number of blade leading-edge pressure measurements and representative operating conditions. These network models are subsequently used to estimate the airloads at intermediate radial locations where only blade pressure measurements at the 3.5% chordwise stations are available.

Prediction of SA 349/2 GV blade loads in high speed flight using several rotor analyses

NASA Technical Reports Server (NTRS)

Gaubert, Michel; Yamauchi, Gloria K.

1987-01-01

The influence of blade dynamics, dynamic stall, and transonic aerodynamics on the predictions of rotor loads in high-speed flight are presented. Data were obtained from an Aerospatiale Gazelle SA 349/2 helicopter with three Grande Vitesse blades. Several analyses are used for this investigation. First, blade dynamics effects on the correlation are studied using three rotor analyses which differ mainly in the method of calculating the blade elastic response. Next, an ONERA dynamic stall model is used to predict retreating blade stall. Finally, advancing blade aerodynamic loads are calculated using a NASA-developed rotorcraft analysis coupled with two transonic finite-difference analyses.

Effect of the Macintosh curved blade size on direct laryngoscopic view in edentulous patients.

PubMed

Kim, Hyerim; Chang, Jee-Eun; Han, Sung-Hee; Lee, Jung-Man; Yoon, Soohyuk; Hwang, Jin-Young

2018-01-01

In the present study, we compared the laryngoscopic view depending on the size of the Macintosh curved blade in edentulous patients. Thirty-five edentulous adult patients scheduled for elective surgery were included in the study. After induction of anesthesia, two direct laryngoscopies were performed alternately using a standard-sized Macintosh curved blade (No. 4 for men and No. 3 for women) and smaller-sized Macintosh curved blade (No. 3 for men and No. 2 for women). During direct laryngoscopy with each blade, two digital photographs of the lateral view were taken when the blade tip was placed in the valleculae; the laryngoscope was lifted to achieve the best laryngeal view. Then, the best laryngeal views were assessed using the percentage of glottic opening (POGO) score. On the photographs of the lateral view of direct laryngoscopy, the angles between the line extending along the laryngoscopic handle and the horizontal line were measured. The POGO score was improved with the smaller-sized blade compared with the standard-sized blade (87.3% [11.8%] vs. 71.3% [20.0%], P<0.001, respectively). The angles between the laryngoscopic handle and the horizontal line were greater with the smaller-sized blade compared to the standard-sized blade when the blade tip was placed on the valleculae and when the laryngoscope was lifted to achieve the best laryngeal view (both P<0.001). Compared to a standard-sized Macintosh blade, a smaller-sized Macintosh curved blade improved the laryngeal exposure in edentulous patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Design and evaluation of low-cost stainless steel fiberglass foam blades for large wind driven generating systems

NASA Technical Reports Server (NTRS)

Eggert, W. S.

1982-01-01

A low cost wind turbine blade based on a stainless steel fiberglass foam Budd blade design concept, was evaluated for its principle characteristics, low cost features, and its advantages and disadvantages. A blade structure was designed and construction methods and materials were selected. A complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program is conducted to provide data to verify the design stress allowables.

Turbine blade tip gap reduction system

DOEpatents

Diakunchak, Ihor S.

2012-09-11

A turbine blade sealing system for reducing a gap between a tip of a turbine blade and a stationary shroud of a turbine engine. The sealing system includes a plurality of flexible seal strips extending from a pressure side of a turbine blade generally orthogonal to the turbine blade. During operation of the turbine engine, the flexible seal strips flex radially outward extending towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the turbine blades and increasing the efficiency of the turbine engine.

A method for turbine blade temperature data segmentation

NASA Astrophysics Data System (ADS)

Feng, Chi; Wang, Li; Gao, Shan

2017-08-01

Turbine blade, as one of the key components of the engine, operates in the badly working conditions. In order to better monitor the temperature status of turbine blades, research on temperature distribution of working blades is significant. The paper applies discrete Fourier transform to develop mathematical models, and the changes of period and peaks are summarized. The changing trends of temperature are reflected in each blade. The trends can be treated as one of the bases of the blade condition monitoring and fault diagnosis.

Pin and roller attachment system for ceramic blades

DOEpatents

Shaffer, J.E.

1995-07-25

In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints. 3 figs.

Orbit Transfer Rocket Engine Technology Program. Automated Preflight Methods Concept Definition. Task E.7

DTIC Science & Technology

1991-12-21

itself. For example, in the case of turbine wheel /blade inspection, remotely obtained blade fatigue data coupled with a life prediction model and...Security, etc. C 2. T/C Assembly for Evidence of Coolant Passage Blockage C 3. HPFTP Turbine Wheel /Blades for Cracks, Fatigue and Damage C 4. HPOTP Turbine... Wheel /Blades for Cracks, Fatigue and Damage C 5. LPFTP Turbine Wheel /Blades for Cracks, Fatigue and Damage C 6. LPOTP Turbine Wheel /Blades for Cracks

Design and evaluation of low-cost stainless steel fiberglass foam blades for large wind driven generating systems

NASA Astrophysics Data System (ADS)

Eggert, W. S.

1982-10-01

A low cost wind turbine blade based on a stainless steel fiberglass foam Budd blade design concept, was evaluated for its principle characteristics, low cost features, and its advantages and disadvantages. A blade structure was designed and construction methods and materials were selected. A complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program is conducted to provide data to verify the design stress allowables.

Development and application of a method for predicting rotor free wake positions and resulting rotor blade air loads. Volume 1: Model and results

NASA Technical Reports Server (NTRS)

Sadler, S. G.

1971-01-01

Rotor wake geometries are predicted by a process similar to the startup of a rotor in a free stream. An array of discrete trailing and shed vortices is generated with vortex strengths corresponding to stepwise radial and azimuthal blade circulations. The array of shed and trailing vortices is limited to an arbitrary number of azimuthal steps behind each blade. The remainder of the wake model of each blade is an arbitrary number of trailing vortices. Vortex element end points were allowed to be transported by the resultant velocity of the free stream and vortex-induced velocities. Wake geometry, wake flow, and wake-induced velocity influence coefficients are generated by this program for use in the blade loads portion of the calculations. Blade loads computations include the effects of nonuniform inflow due to a free wake, nonlinear airfoil characteristics, and response of flexible blades to the applied loads. Computed wake flows and blade loads are compared with experimentally measured data. Predicted blade loads, response and shears and moments are obtained for a model rotor system having two independent rotors. The effects of advance ratio, vertical separation of rotors, different blade radius ratios, and different azimuthal spacing of the blades of one rotor with respect to the other are investigated.

Direct Numerical Simulations of a Full Stationary Wind-Turbine Blade

NASA Astrophysics Data System (ADS)

Qamar, Adnan; Zhang, Wei; Gao, Wei; Samtaney, Ravi

2014-11-01

Direct numerical simulation of flow past a full stationary wind-turbine blade is carried out at Reynolds number, Re = 10,000 placed at 0 and 5 (degree) angle of attack. The study is targeted to create a DNS database for verification of solvers and turbulent models that are utilized in wind-turbine modeling applications. The full blade comprises of a circular cylinder base that is attached to a spanwise varying airfoil cross-section profile (without twist). An overlapping composite grid technique is utilized to perform these DNS computations, which permits block structure in the mapped computational space. Different flow shedding regimes are observed along the blade length. Von-Karman shedding is observed in the cylinder shaft region of the turbine blade. Along the airfoil cross-section of the blade, near body shear layer breakdown is observed. A long tip vortex originates from the blade tip region, which exits the computational plane without being perturbed. Laminar to turbulent flow transition is observed along the blade length. The turbulent fluctuations amplitude decreases along the blade length and the flow remains laminar regime in the vicinity of the blade tip. The Strouhal number is found to decrease monotonously along the blade length. Average lift and drag coefficients are also reported for the cases investigated. Supported by funding under a KAUST OCRF-CRG grant.

Temperatures and Stresses on Hollow Blades For Gas Turbines

NASA Technical Reports Server (NTRS)

Pollmann, Erich

1947-01-01

The present treatise reports on theoretical investigations and test-stand measurements which were carried out in the BMW Flugmotoren GMbH in developing the hollow blade for exhaust gas turbines. As an introduction the temperature variation and the stress on a turbine blade for a gas temperature of 900 degrees and circumferential velocities of 600 meters per second are discussed. The assumptions onthe heat transfer coefficients at the blade profile are supported by tests on an electrically heated blade model. The temperature distribution in the cross section of a blade Is thoroughly investigated and the temperature field determined for a special case. A method for calculation of the thermal stresses in turbine blades for a given temperature distribution is indicated. The effect of the heat radiation on the blade temperature also is dealt with. Test-stand experiments on turbine blades are evaluated, particularly with respect to temperature distribution in the cross section; maximum and minimum temperature in the cross section are ascertained. Finally, the application of the hollow blade for a stationary gas turbine is investigated. Starting from a setup for 550 C gas temperature the improvement of the thermal efficiency and the fuel consumption are considered as well as the increase of the useful power by use of high temperatures. The power required for blade cooling is taken into account.

Design and fabrication of durable owner-built wind turbine blades

NASA Astrophysics Data System (ADS)

Queeney, R. A.

To find the configuration of materials that will produce lightweight, durable wind tubine blades, a composite material blade consisting of an aluminum tubing spar, a foam insulating filler and a glass reinforced plastic skin was analyzed. Various tensile and creep tests were conducted on model blades, and a computer analysis determined the best configuration for the blade.

An Investigation of End-Wall Vortex Cavitation in a High Reynolds Number Axial-Flow Pump

DTIC Science & Technology

1989-08-01

groove treatment, and various winglet configurations. Notwithstanding the differences between compressor and turbine flow fields, the deep- groove...treatment and pressure-surface winglet reduced the leakage by about 15 percent as reported by Booth et al. [20]. Additional numerical and experimental...the blade appears stationary because the eye blends the individual pictures together similar to a motion picture projection. However, at lower

Advanced Turbine Technology Applications Project (ATTAP) 1993 annual report

NASA Technical Reports Server (NTRS)

1994-01-01

This report summarizes work performed by AlliedSignal Engines, a unit of AlliedSignal Aerospace Company, during calendar year 1993, toward development and demonstration of structural ceramic technology for automotive gas turbine engines. This work was performed for the U.S. Department of Energy (DOE) under National Aeronautics and Space Administration (NASA) Contract DEN3-335, Advanced Turbine Technology Applications Project (ATFAP). During 1993, the test bed used to demonstrate ceramic technology was changed from the AlliedSignal Engines/Garrett Model AGT101 regenerated gas turbine engine to the Model 331-200(CT) engine. The 331-200(CT) ceramic demonstrator is a fully-developed test platform based on the existing production AlliedSignal 331-200(ER) gas turbine auxiliary power unit (APU), and is well suited to evaluating ceramic turbine blades and nozzles. In addition, commonality of the 331-200(CT) engine with existing gas turbine APU's in commercial service provides the potential for field testing of ceramic components. The 1993 ATTAP activities emphasized design modifications of the 331-200 engine test bed to accommodate ceramic first-stage turbine nozzles and blades, fabrication of the ceramic components, ceramic component proof and rig tests, operational tests of the test bed equipped with the ceramic components, and refinement of critical ceramic design technologies.

Improving Vector Evaluated Particle Swarm Optimisation by Incorporating Nondominated Solutions

PubMed Central

Lim, Kian Sheng; Ibrahim, Zuwairie; Buyamin, Salinda; Ahmad, Anita; Naim, Faradila; Ghazali, Kamarul Hawari; Mokhtar, Norrima

2013-01-01

The Vector Evaluated Particle Swarm Optimisation algorithm is widely used to solve multiobjective optimisation problems. This algorithm optimises one objective using a swarm of particles where their movements are guided by the best solution found by another swarm. However, the best solution of a swarm is only updated when a newly generated solution has better fitness than the best solution at the objective function optimised by that swarm, yielding poor solutions for the multiobjective optimisation problems. Thus, an improved Vector Evaluated Particle Swarm Optimisation algorithm is introduced by incorporating the nondominated solutions as the guidance for a swarm rather than using the best solution from another swarm. In this paper, the performance of improved Vector Evaluated Particle Swarm Optimisation algorithm is investigated using performance measures such as the number of nondominated solutions found, the generational distance, the spread, and the hypervolume. The results suggest that the improved Vector Evaluated Particle Swarm Optimisation algorithm has impressive performance compared with the conventional Vector Evaluated Particle Swarm Optimisation algorithm. PMID:23737718

Improving Vector Evaluated Particle Swarm Optimisation by incorporating nondominated solutions.

PubMed

Lim, Kian Sheng; Ibrahim, Zuwairie; Buyamin, Salinda; Ahmad, Anita; Naim, Faradila; Ghazali, Kamarul Hawari; Mokhtar, Norrima

2013-01-01

The Vector Evaluated Particle Swarm Optimisation algorithm is widely used to solve multiobjective optimisation problems. This algorithm optimises one objective using a swarm of particles where their movements are guided by the best solution found by another swarm. However, the best solution of a swarm is only updated when a newly generated solution has better fitness than the best solution at the objective function optimised by that swarm, yielding poor solutions for the multiobjective optimisation problems. Thus, an improved Vector Evaluated Particle Swarm Optimisation algorithm is introduced by incorporating the nondominated solutions as the guidance for a swarm rather than using the best solution from another swarm. In this paper, the performance of improved Vector Evaluated Particle Swarm Optimisation algorithm is investigated using performance measures such as the number of nondominated solutions found, the generational distance, the spread, and the hypervolume. The results suggest that the improved Vector Evaluated Particle Swarm Optimisation algorithm has impressive performance compared with the conventional Vector Evaluated Particle Swarm Optimisation algorithm.

Shoulder Blade Squeeze (Posture Exercise)

MedlinePlus

... Weight Exercise at Home Shoulder Blade Squeeze Shoulder Blade Squeeze Make an Appointment Ask a Question Find ... it: Stand straight and tall. Pull your shoulder blades back and slightly downward to bring your elbows ...

Fabrication of low-cost Mod-OA wood composite wind turbine blades

NASA Technical Reports Server (NTRS)

Lark, R. F.; Gougeon, M.; Thomas, G.; Zuteck, M.

1983-01-01

The wood composite blades were fabricated by using epoxy resin-bonded laminates of Douglas fir veneers for the leading edge spar sections and honeycomb-cored birch plywood panels for the blade trailing edge or afterbody sections. The blade was joined to the wind turbine hub assembly by epoxy resin-bonded steel load take-off studs. The wood composite blades were installed in the Mod-OA wind turbine test facility at Kahuku, Hawaii. The wood composite blades have successfully completed high power (average of 150 kW) operations for an eighteen month period (nearly 8,000 hr) before replacement with another set of wood composite blades. The original set of blades was taken out of service because of the failure of the shank on one stud. An inspection of the blades at NASA-Lewis showed that the shank failure was caused by a high stress concentration at a corrosion pit on the shank fillet radius which resulted in fatigue stresses in excess of the endurance limit.

Structural Tailoring of Advanced Turboprops (STAT). Theoretical manual

NASA Technical Reports Server (NTRS)

Brown, K. W.

1992-01-01

This manual describes the theories in the Structural Tailoring of Advanced Turboprops (STAT) computer program, which was developed to perform numerical optimizations on highly swept propfan blades. The optimization procedure seeks to minimize an objective function, defined as either direct operating cost or aeroelastic differences between a blade and its scaled model, by tuning internal and external geometry variables that must satisfy realistic blade design constraints. The STAT analyses include an aerodynamic efficiency evaluation, a finite element stress and vibration analysis, an acoustic analysis, a flutter analysis, and a once-per-revolution (1-p) forced response life prediction capability. The STAT constraints include blade stresses, blade resonances, flutter, tip displacements, and a 1-P forced response life fraction. The STAT variables include all blade internal and external geometry parameters needed to define a composite material blade. The STAT objective function is dependent upon a blade baseline definition which the user supplies to describe a current blade design for cost optimization or for the tailoring of an aeroelastic scale model.

Structural Tailoring of Advanced Turboprops (STAT). Theoretical manual

NASA Astrophysics Data System (ADS)

Brown, K. W.

1992-10-01

This manual describes the theories in the Structural Tailoring of Advanced Turboprops (STAT) computer program, which was developed to perform numerical optimizations on highly swept propfan blades. The optimization procedure seeks to minimize an objective function, defined as either direct operating cost or aeroelastic differences between a blade and its scaled model, by tuning internal and external geometry variables that must satisfy realistic blade design constraints. The STAT analyses include an aerodynamic efficiency evaluation, a finite element stress and vibration analysis, an acoustic analysis, a flutter analysis, and a once-per-revolution (1-p) forced response life prediction capability. The STAT constraints include blade stresses, blade resonances, flutter, tip displacements, and a 1-P forced response life fraction. The STAT variables include all blade internal and external geometry parameters needed to define a composite material blade. The STAT objective function is dependent upon a blade baseline definition which the user supplies to describe a current blade design for cost optimization or for the tailoring of an aeroelastic scale model.

The effect of tip vortex structure on helicopter noise due to blade/vortex interaction

NASA Technical Reports Server (NTRS)

Wolf, T. L.; Widnall, S. E.

1978-01-01

A potential cause of helicopter impulsive noise, commonly called blade slap, is the unsteady lift fluctuation on a rotor blade due to interaction with the vortex trailed from another blade. The relationship between vortex structure and the intensity of the acoustic signal is investigated. The analysis is based on a theoretical model for blade/vortex interaction. Unsteady lift on the blades due to blade/vortex interaction is calculated using linear unsteady aerodynamic theory, and expressions are derived for the directivity, frequency spectrum, and transient signal of the radiated noise. An inviscid rollup model is used to calculate the velocity profile in the trailing vortex from the spanwise distribution of blade tip loading. A few cases of tip loading are investigated, and numerical results are presented for the unsteady lift and acoustic signal due to blade/vortex interaction. The intensity of the acoustic signal is shown to be quite sensitive to changes in tip vortex structure.

Monitoring of wind turbines

DOEpatents

White, Jonathan R.; Adams, Douglas E.; Paquette, Josh

2017-07-25

Method and apparatus for determining the deflection or curvature of a rotating blade, such as a wind turbine blade or a helicopter blade. Also, methods and apparatus for establishing an inertial reference system on a rotating blade.

Hot-blade stripper for polyester insulation on FCC

NASA Technical Reports Server (NTRS)

Angele, W.; Chambers, C. M.

1971-01-01

Stripper incorporates a blade which is electrically heated to a controlled temperature. Heated blade softens and strips insulation from cable while paper ribbon removes insulation material and keeps blade clean for next operation.

The role of gravity in leaf blade curvatures

NASA Technical Reports Server (NTRS)

Hayes, A. B.

1984-01-01

In the past year we have gained useful information on several aspects of leaf blade growth. The most important observations are as follows: The C(14)-1AA moves preferentially in a gravipositive dorsiventral direction through the blade. This movement is inhibited by inversion of the blade. The responding cells in leaf blade hyponasty are in the lower epidermis and bundle sheath cells. Two additional responses in the leaf were characterized. In addition to blade curvature, the leaf shows petiole curvature and changes in the liminal angle subtended by the pulvinus. Ethylene production was studied under a number of conditions. The blade, rather than the petiole or pulvinus, is the principal site of auxin-promoted ethylene synthesis. The effects of a variety of agents on the blade, including gibberellic acid, abscisic acid, vanadate, low pH buffers, and blue light were reviewed.

Effects of geometric variables on rub characteristics of Ti-6Al-4V

NASA Technical Reports Server (NTRS)

Bill, R. C.; Wolak, J.; Wisander, D. W.

1981-01-01

Experiments simulating rub interactions between Ti-6Al-4V blade tips and various seal materials were conducted. The number of blade tips and the blade tip geometry were varied to determine their effects on rub forces and on wear phenomena. Contact was found to be quite unsteady for all blade tip geometries except for those incorporating deliberately rounded blade tips. The unsteady contact was characterized by long periods of rubbing contact and increasing blade tip that terminated in sudden rapid metal removal, sometimes accompanied by tearing and disruption of porous seal material under the rub surface. A model describing the blade tip loading is proposed and is based on the propagation of an elastic stress wave through the seal material as the seal material is dynamically compressed by the blade tip leading edge.

Turbine blade squealer tip rail with fence members

DOE Office of Scientific and Technical Information (OSTI.GOV)

Little, David A

2012-11-20

A turbine blade includes an airfoil, a blade tip section, a squealer tip rail, and a plurality of chordally spaced fence members. The blade tip section includes a blade tip floor located at an end of the airfoil distal from the root. The blade tip floor includes a pressure side and a suction side joined together at chordally spaced apart leading and trailing edges of the airfoil. The squealer tip rail extends radially outwardly from the blade tip floor adjacent to the suction side and extends from a first location adjacent to the airfoil trailing edge to a second locationmore » adjacent to the airfoil leading edge. The fence members are located between the airfoil leading and trailing edges and extend radially outwardly from the blade tip floor and axially from the squealer tip rail toward the pressure side.« less

Investigation of a Cermet Gas-turbine-blade Material of Titanium Carbide Infiltrated with Hastalloy C

NASA Technical Reports Server (NTRS)

Hoffman, Charles A

1955-01-01

A cermet composition was investigated as a potential material for gas-turbine blades. Blades of HS-21 alloy were also operated in the engine simultaneously to provide a basis of comparison. The cermet blades survived as long as approximately 312-1/2 hours at about 1500 degrees F with an average midspan centrifugal stress of approximately 11,500 psi. The alloy blade midspan stress was about 15,300 psi. Because of extensive damage to both types of blade due to external causes, a reliable comparison of operating lives could not be made. The cermet blades tended to fail in the airfoil rather than in the base, although the base was the usual location of failure in a prior study of cold-pressed and sintered cermets of other compositions with the same blade shape.

Forced response of mistuned bladed disks

NASA Technical Reports Server (NTRS)

Pierre, Christophe

1994-01-01

Small mistuning can cause large, catastrophic changes in blade vibrational response whereby the amplitudes of vibration of some blades may increase by several hundred percent. This can produce 'rogue' blades and HCF failure. The free and forced responses may be highly sensitive to mistuning, and the tuned system predictions may be qualitatively in error and grossly underestimate blade forced response and overestimate fatigue life. Manufacturing tolerances, material non-uniformities, nonidentical root fixtures, and in-service degradation result in blade-to-blade differences that destroy cyclic symmetry in bladed discs. Therefore, a credible forced response prediction system for turbomachinery vibration must take mistuning into account. This report addresses these problems, states several objectives, and introduces NASA research program thrusts concerning this problem. This report was given during the NASA LeRC Workshop on Forced Response in Turbomachinery in August of 1993.

Vibration and flutter of mistuned bladed-disk assemblies

NASA Technical Reports Server (NTRS)

Kaza, K. R. V.; Kielb, R. E.

1984-01-01

An analytical model for investigating vibration and flutter of mistuned bladed disk assemblies is presented. This model accounts for elastic, inertial and aerodynamic coupling between bending and torsional motions of each individual blade, elastic and inertial couplings between the blades and the disk, and aerodynamic coupling among the blades. The disk was modeled as a circular plate with constant thickness and each blade was represented by a twisted, slender, straight, nonuniform, elastic beam with a symmetric cross section. The elastic axis, inertia axis, and the tension axis were taken to be noncoincident and the structural warping of the section was explicitly considered. The blade aerodynamic loading in the subsonic and supersonic flow regimes was obtained from two-dimensional unsteady, cascade theories. All the possible standing wave modes of the disk and traveling wave modes of the blades were included. The equations of motion were derived by using the energy method in conjunction with the assumed mode shapes for the disk and the blades. Continuities of displacement and slope at the blade-disk junction were maintained. The equations were solved to investigate the effects of blade-disk coupling and blade frequency mistuning on vibration and flutter. Results showed that the flexibility of practical disks such as those used for current generation turbofans did not have a significant influence on either the tuned or mistuned flutter characteristics. However, the disk flexibility may have a strong influence on some of the system frequencies and on forced response.

Vibration and flutter of mistuned bladed-disk assemblies

NASA Technical Reports Server (NTRS)

Rao, K.; Kaza, V.; Kielb, R. E.

1984-01-01

An analytical model for investigating vibration and flutter of mistuned bladed disk assemblies is presented. This model accounts for elastic, inertial and aerodynamic coupling between bending and torsional motions of each individual blade, elastic and inertial couplings between the blades and the disk, and aerodynamic coupling among the blades. The disk was modeled as a circular plate with constant thickness and each blade was represented by a twisted, slender, straight, nonuniform, elastic beam with a symmetric cross section. The elastic axis, inertia axis, and the tension axis were taken to be noncoincident and the structural warping of the section was explicitly considered. The blade aerodynamic loading in the subsonic and supersonic flow regimes was obtained from two-dimensional unsteady, cascade theories. All the possible standing wave modes of the disk and traveling wave modes of the blades were included. The equations of motion were derived by using the energy method in conjunction with the assumed mode shapes for the disk and the blades. Continuities of displacement and slope at the blade-disk junction were maintained. The equations were solved to investigate the effects of blade-disk coupling and blade frequency mistuning on vibration and flutter. Results showed that the flexibility of practical disks such as those used for current generation turbufans did not have a significant influence on either the tuned or mistuned flutter characteristics. However, the disk flexibility may have a strong influence on some of the system frequencies and on forced response.

Determination of Turbine Blade Life from Engine Field Data

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

2012-01-01

It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal mechanical fatigue as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) Thermal-mechanical fatigue, (2) Oxidation/Erosion, and (3) "Other." From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L(sub 10) blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to oxidation/erosion equaled that attributed to thermal-mechanical fatigue. The category that contributed most to blade failure was Other. If there were there no blade failures attributed to oxidation/erosion and thermal-mechanical fatigue, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

Smart helicopter rotor with active blade tips

NASA Astrophysics Data System (ADS)

Bernhard, Andreas Paul Friedrich

2000-10-01

The smart active blade tip (SABT) rotor is an on-blade rotor vibration reduction system, incorporating active blade tips that can be independently pitched with respect to the main blade. The active blade tip rotor development included an experimental test program culminating in a Mach scale hover test, and a parallel development of a coupled, elastic actuator and rotor blade analysis for preliminary design studies and hover performance prediction. The experimental testing focussed on a small scale rotor on a bearingless Bell-412 hub. The fabricated Mach-scale active-tip rotor has a diameter of 1.524 m, a blade chord of 76.2 mm and incorporated a 10% span active tip. The nominal operating speed is 2000 rpm, giving a tip Mach number of 0.47. The blade tips are driven by a novel piezo-induced bending-torsion coupled actuator beam, located spanwise in the hollow mid-cell of the main rotor blade. In hover at 2000 rpm, at 2 deg collective, and for an actuation of 125 Vrms, the measured blade tip deflection at the first four rotor harmonics is between +/-1.7 and +/-2.8 deg, increasing to +/-5.3 deg at 5/rev with resonant amplification. The corresponding oscillatory amplitude of the rotor thrust coefficient is between 0.7 · 10-3 and 1.3 · 10-1 at the first four rotor harmonics, increasing to 2.1 · 10-3 at 5/rev. In general, the experimental blade tip frequency response and corresponding rotor thrust response are well captured by the analysis. The flexbeam root flap bending moment is predicted in trend, but is significantly over-estimated. The blade tips did not deflect as expected at high collective settings, because of the blade tip shaft locking up in the bearing. This is caused by the high flap bending moment on the blade tip shaft. Redesign of the blade tip shaft assembly and bearing support is identified as the primary design improvement for future research. The active blade tip rotor was also used as a testbed for the evaluation of an adaptive neural-network based control algorithm. Effective background vibration reduction of an intentional 1/rev hover imbalance was demonstrated. The control algorithm also showed the capability to generate desired multi-frequency control loads on the hub, based on artificial signal injection into the vibration measurement. The research program demonstrates the technical feasibility of the active blade tip concept for vibration reduction and warrants further investigation in terms of closed loop forward flight tests in the windtunnel and full scale design studies.

Loads and performance data from a wind-tunnel test of model articulated helicopter rotors with 2 different blade torsional stiffnesses

NASA Technical Reports Server (NTRS)

Yeager, W. T., Jr.; Mantay, W. R.

1983-01-01

A passive means of tailoring helicopter rotor blades to improve performance and reduce loads was evaluated. The parameters investigated were blade torsional stiffness, blade section camber, and distance between blade structural elastic axis and blade tip aerodynamic center. This offset was accomplished by sweeping the tip. The investigation was conducted at advance ratios of 0.20, 0.30, and 0.40. Data are presented without analysis; however, cross referencing of performance data and harmonic loads data may be useful to the analyst for validating aeroelastic theories and design methodologies as well as for evaluating passive aeroelastic tailoring or rotor blade parameters.

SSME single crystal turbine blade dynamics

NASA Technical Reports Server (NTRS)

Moss, Larry A.; Smith, Todd E.

1987-01-01

A study was performed to determine the dynamic characteristics of the Space Shuttle main engine high pressure fuel turbopump (HPFTP) blades made of single crystal (SC) material. The first and second stage drive turbine blades of HPFTP were examined. The nonrotating natural frequencies were determined experimentally and analytically. The experimental results of the SC second stage blade were used to verify the analytical procedures. The analytical study examined the SC first stage blade natural frequencies with respect to crystal orientation at typical operating conditions. The SC blade dynamic response was predicted to be less than the directionally solidified blade. Crystal axis orientation optimization indicated the third mode interference will exist in any SC orientation.

Design of helicopter rotor blades for optimum dynamic characteristics

NASA Technical Reports Server (NTRS)

Peters, D. A.; Ko, T.; Korn, A.; Rossow, M. P.

1984-01-01

The optimal design of helicopter rotor blades is addressed. The forced response of an initial (i.e., non-optimized) blade to those of a final (optimized) blade are compared. Response of starting design and optimal designs for varying forcing frequencies, blade response to harmonics of rotor speed, and derivation of mass and stiffness matrices or functions of natural frequencies are discussed.

Eutectic Composite Turbine Blade Development

DTIC Science & Technology

1976-11-01

turbine blades for aircraft engines . An MC carbide fiber reinforced eutectic alloy, NiTaC-13...composites in turbine blades for aircraft engines . An MC carbide fiber reinforced eutectic alloy, NiTaC-13 and the low pressure turbine blade of the...identified that appeared to have potential for application to aircraft engine turbine blade hardware. The potential benefits offered by these materials

75 FR 59065 - Airworthiness Directives; Turboméca S.A. Arriel 2B and 2B1 Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-27

... displacement of the HP blade relative to the disk in case of blade lock rupture or opening, therefore... limit axial displacement of the HP blade relative to the disk in case of blade lock rupture or opening... and the HP blade platform. Introduction of these dampers has demonstrated to limit axial displacement...

Flapping inertia for selected rotor blades

NASA Technical Reports Server (NTRS)

Berry, John D.; May, Matthew J.

1991-01-01

Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected.

Hashin Failure Theory Based Damage Assessment Methodology of Composite Tidal Turbine Blades and Implications for the Blade Design

NASA Astrophysics Data System (ADS)

Yu, Guo-qing; Ren, Yi-ru; Zhang, Tian-tian; Xiao, Wan-shen; Jiang, Hong-yong

2018-04-01

A damage assessment methodology based on the Hashin failure theory for glass fiber reinforced polymer (GFRP) composite blade is proposed. The typical failure mechanisms including the fiber tension/compression and matrix tension/compression are considered to describe the damage behaviors. To give the flapwise and edgewise loading along the blade span, the Blade Element Momentum Theory (BEMT) is adopted. In conjunction with the hydrodynamic analysis, the structural analysis of the composite blade is cooperatively performed with the Hashin damage model. The damage characteristics of the composite blade, under normal and extreme operational conditions, are comparatively analyzed. Numerical results demonstrate that the matrix tension damage is the most significant failure mode which occurs in the mid-span of the blade. The blade internal configurations including the box-beam, Ibeam, left-C beam and right-C beam are compared and analyzed. The GFRP and carbon fiber reinforced polymer (CFRP) are considered and combined. Numerical results show that the I-beam is the best structural type. The structural performance of composite tidal turbine blades could be improved by combining the GFRP and CFRP structure considering the damage and cost-effectiveness synthetically.

Measurement of Unsteady Aerodynamics Load on the Blade of Field Horizontal Axis Wind Turbine

NASA Astrophysics Data System (ADS)

Kamada, Yasunari; Maeda, Takao; Naito, Keita; Ouchi, Yuu; Kozawa, Masayoshi

This paper describes an experimental field study of the rotor aerodynamics of wind turbines. The test wind turbine is a horizontal axis wind turbine, or: HAWT with a diameter of 10m. The pressure distributions on the rotating blade are measured with multi point pressure transducers. Sectional aerodynamic forces are analyzed from pressure distribution. Blade root moments are measured simultaneously by a pair of strain gauges. The inflow wind is measured by a three component sonic anemometer, the local inflow of the blade section are measured by a pair of 7 hole Pitot tubes. The relation between the aerodynamic moments on the blade root from pressure distribution and the mechanical moment from strain gauges is discussed. The aerodynamic moments are estimated from the sectional aerodynamic forces and show oscillation caused by local wind speed and direction change. The mechanical moment shows similar oscillation to the aerodynamic excepting the short period oscillation of the blade first mode frequency. The fluctuation of the sectional aerodynamic force triggers resonant blade oscillations. Where stall is present along the blade section, the blade's first mode frequency is dominant. Without stall, the rotating frequency is dominant in the blade root moment.

Examination, evaluation and repair of laminated wood blades after service on the Mod-OA wind turbine

NASA Technical Reports Server (NTRS)

Faddoul, J. R.

1983-01-01

Laminated wood blades were designed, fabricated, and installed on a 200-KW wind turbine (Mod-OA). The machine uses a two-blade rotor with a diameter of 38.1 m (125 ft). Each blade weights less than 1361 kg (3000 lb). After operating in the field, two blade sets were returned for inspection. One set had been in Hawaii for 17 months (7844 hr of operation) and the other had been at Block Island, Rhode Island, for 26 months (22 months operating - 7564 hr). The Hawaii set was returned because of one of the studs that holds the blade to the hub had failed. This was found to be caused by a combination of improper installation and inadequate corrosion protection. No other problems were found. The broken stud (along with four others that were badly corroded) was replaced and the blades are now in storage. The Block Island set of blades was returned at the completion of the test program, but one blade was found to have developed a crack in the leading edge along the entire span. This crack was found to be the result of a manufacturing process problem but was not structurally critical. When a load-deflection test was conducted on the cracked blade, the response was identical to that measured before installation. In general, the laminate quality of both blade sets was excellent. No significant internal delamination or structural defects were found in any blade. The stud bonding process requires close tolerance control and adequate corrosion protection, but studs can be removed and replaced without major problems. Moisture content stabilization does not appear to be a problem, and laminated wood blades are satisfactory for long-term operation on Mod-OA wind turbines.

The turbomachine blading design using S2-S1 approach

NASA Technical Reports Server (NTRS)

Luu, T. S.; Bencherif, L.; Viney, B.; Duc, J. M. Nguyen

1991-01-01

The boundary conditions corresponding to the design problem when the blades being simulated by the bound vorticity distribution are presented. The 3D flow is analyzed by the two steps S2 - S1 approach. In the first step, the number of blades is supposed to be infinite, the vortex distribution is transformed into an axisymmetric one, so that the flow field can be analyzed in a meridional plane. The thickness distribution of the blade producing the flow channel striction is taken into account by the modification of metric tensor in the continuity equation. Using the meridional stream function to define the flow field, the mass conservation is satisfied automatically. The governing equation is deduced from the relation between the azimuthal component of the vorticity and the meridional velocity. The value of the azimuthal component of the vorticity is provided by the hub to shroud equilibrium condition. This step leads to the determination of the axisymmetric stream sheets as well as the approximate camber surface of the blade. In the second step, the finite number of blades is taken into account, the inverse problem corresponding to the blade to blade flow confined in each stream sheet is analyzed. The momentum equation implies that the free vortex of the absolute velocity must be tangential to the stream sheet. The governing equation for the blade to blade flow stream function is deduced from this condition. At the beginning, the upper and the lower surfaces of the blades are created from the camber surface obtained from the first step with the assigned thickness distribution. The bound vorticity distribution and the penetrating flux conservation applied on the presumed blade surface constitute the boundary conditions of the inverse problem. The detection of this flux leads to the rectification of the geometry of the blades.

Thin-film microextraction coupled to LC-ESI-MS/MS for determination of quaternary ammonium compounds in water samples.

PubMed

Boyacı, Ezel; Sparham, Chris; Pawliszyn, Janusz

2014-01-01

The dual nature of the quaternary ammonium compounds, having permanently charged hydrophilic quaternary ammonium heads and long-chain hydrophobic tails, makes the sample preparation step and analysis of these compounds challenging. A high-throughput method based on thin-film solid-phase microextraction (SPME) and liquid chromatography mass spectrometry was developed for simultaneous quantitative analysis of nine benzylic and aliphatic quaternary ammonium compounds. Chromatographic separation and detection of analytes were obtained in reverse-phase mode in 8 min using a triple quadrupole mass spectrometer. Hydrophilic lipophilic balance particle-coated blades were found to be the most suitable among the different coatings tested in terms of recoveries and carryover on the blades. For desorption solvents, 70/30, v/v (A/B) with 0.1 % formic acid (where A is 10 mM ammonium acetate in acetonitrile/water (95/5 , v/v) and B is 0.1 %  (v/v) formic acid in isopropyl alcohol) was shown to be the most efficient solvent for the desorption of the analytes from the SPME sorbent. The SPME method was optimised in terms of extraction, pH, and preconditioning, as well as extraction and desorption times. Optimum conditions were 45 min of extraction time and 15 min of desorption time, all with agitation. The extraction was found to be optimum in a range of pH 6.0 to 8.0, which is consistent with the natural pH of water samples. Wide linear dynamic ranges with the developed method were obtained for each compound, enabling the application of the method for a wide range of concentrations. The developed method was validated according to the Food and Drug Administration criteria. The proposed method is the first SPME-based approach describing the applicability of the high-throughput thin-film SPME in a 96-well system for analysis of such challenging compounds.

Performance of friction dampersin geometric mistuned bladed disk assembly subjected to random excitations

NASA Astrophysics Data System (ADS)

Cha, Douksoon

2018-07-01

In this study, the performance of friction dampers of a geometric mistuned bladed disk assembly is examined under random excitations. The results are represented by non-dimensional variables. It is shown that the performance of the blade-to-blade damper can deteriorate when the correlated narrow band excitations have a dominant frequency near the 1st natural frequency of the bladed disk assembly. Based on a simple model of a geometric mistuned bladed disk assembly, the analytical technique shows an efficient way to design friction dampers.

Energy efficient engine high-pressure turbine supersonic cascade technology report

NASA Technical Reports Server (NTRS)

Kopper, F. C.; Milano, R.; Davis, R. L.; Dring, R. P.; Stoeffler, R. C.

1981-01-01

The performance of two vane endwall geometries and three blade sections for the high-pressure turbine was evaluated in terms of the efficiency requirements of the Energy Efficient Engine high-pressure turbine component. The van endwall designs featured a straight wall and S-wall configuration. The blade designs included a base blade, straightback blade, and overcambered blade. Test results indicated that the S-wall vane configuration and the base blade configuration offered the most promising performance characteristics for the Energy Efficient Engine high-pressure turbine component.

User satisfaction and forces generated during laryngoscopy using disposable Miller blades: a manikin study.

PubMed

Sudhir, G; Wilkes, A R; Clyburn, P; Aguilera, I; Hall, J E

2007-10-01

Increasing awareness of prion-related diseases has led to an increase in the number of disposable laryngoscope blades available. We compared 11 disposable and standard re-usable Miller size 1 blades. In this manikin-based study, we studied user satisfaction for field of view at laryngoscopy, build quality and users' willingness to use the blade in an emergency situation. These were found to be better with metal disposable blades (p

Color Imaging management in film processing

NASA Astrophysics Data System (ADS)

Tremeau, Alain; Konik, Hubert; Colantoni, Philippe

2003-12-01

The latest research projects in the laboratory LIGIV concerns capture, processing, archiving and display of color images considering the trichromatic nature of the Human Vision System (HSV). Among these projects one addresses digital cinematographic film sequences of high resolution and dynamic range. This project aims to optimize the use of content for the post-production operators and for the end user. The studies presented in this paper address the use of metadata to optimise the consumption of video content on a device of user's choice independent of the nature of the equipment that captured the content. Optimising consumption includes enhancing the quality of image reconstruction on a display. Another part of this project addresses the content-based adaptation of image display. Main focus is on Regions of Interest (ROI) operations, based on the ROI concepts of MPEG-7. The aim of this second part is to characterize and ensure the conditions of display even if display device or display media changes. This requires firstly the definition of a reference color space and the definition of bi-directional color transformations for each peripheral device (camera, display, film recorder, etc.). The complicating factor is that different devices have different color gamuts, depending on the chromaticity of their primaries and the ambient illumination under which they are viewed. To match the displayed image to the aimed appearance, all kind of production metadata (camera specification, camera colour primaries, lighting conditions) should be associated to the film material. Metadata and content build together rich content. The author is assumed to specify conditions as known from digital graphics arts. To control image pre-processing and image post-processing, these specifications should be contained in the film's metadata. The specifications are related to the ICC profiles but need additionally consider mesopic viewing conditions.

Preparing our Paralympians: research and development at Ossur, UK. Interview by Sarah A. Curran.

PubMed

Hirons, Richard

2012-09-01

In the last 25 years, the continuous evolution in the design of prostheses for individuals with transfemoral and transtibial amputations has been remarkable. Mirroring this development is the dependency and expectancy of the prosthesis technology by the athletes, coaches and other personnel involved in creating Paralympians of today and the future. Össur is recognised as a leader in designing innovative prosthetic products that have contributed worldwide to developing leading Paralympians. The opening section of this article presents an overview of the new Össur products for 2012. Discussion is also focussed on how Össur's high-function prosthetic products are integrated into an athlete's training regime. With involvement of the clinical team discussion is also expanded to recognise the important contribution coaching staff has on optimising performance of a Paralympian's training regime. The dialogue continues with a viewpoint on whether Oscar Pistorius, the face of Össur who wears Flex-Foot Cheetah blades, should participate in the Olympics and Paralympics. While the conclusion of this article may leave more questions than answers, the technology and products offered by Össur provide for a credible foundation and preparation for future challenges beyond the London 2012 Paralympic Games.

Optimisation of environmental remediation: how to select and use the reference levels.

PubMed

Balonov, M; Chipiga, L; Kiselev, S; Sneve, M; Yankovich, T; Proehl, G

2018-06-01

A number of past industrial activities and accidents have resulted in the radioactive contamination of large areas at many sites around the world, giving rise to a need for remediation. According to the International Commission on Radiological Protection (ICRP) and International Atomic Energy Agency (IAEA), such situations should be managed as existing exposure situations (ExESs). Control of exposure to the public in ExESs is based on the application of appropriate reference levels (RLs) for residual doses. The implementation of this potentially fruitful concept for the optimisation of remediation in various regions is hampered by a lack of practical experience and relevant guidance. This paper suggests a generic methodology for the selection of numeric values of relevant RLs both in terms of residual annual effective dose and derived RLs (DRLs) based on an appropriate dose assessment. The value for an RL should be selected in the range of the annual residual effective dose of 1-20 mSv, depending on the prevailing circumstances for the exposure under consideration. Within this range, RL values should be chosen by the following assessment steps: (a) assessment of the projected dose, i.e. the dose to a representative person without remedial actions by means of a realistic model as opposed to a conservative model; (b) modelling of the residual dose to a representative person following application of feasible remedial actions; and (c) selection of an RL value between the projected and residual doses, taking account of the prevailing social and economic conditions. This paper also contains some recommendations for practical implementation of the selected RLs for the optimisation of public protection. The suggested methodology used for the selection of RLs (in terms of dose) and the calculation of DRLs (in terms of activity concentration in food, ambient dose rate, etc) has been illustrated by a retrospective analysis of post-Chernobyl monitoring and modelling data from the Bryansk region, Russia, 2001. From this example, it follows that analysis of real data leads to the selection of an RL from a relatively narrow annual dose range (in this case, about 2-3 mSv), from which relevant DRLs can be calculated and directly used for optimisation of the remediation programme.

Experimental evidence of inter-blade cavitation vortex development in Francis turbines at deep part load condition

NASA Astrophysics Data System (ADS)

Yamamoto, K.; Müller, A.; Favrel, A.; Avellan, F.

2017-10-01

Francis turbines are subject to various types of cavitation flow depending on the operating condition. To enable a smooth integration of the renewable energy sources, hydraulic machines are now increasingly required to extend their operating range, especially down to extremely low discharge conditions called deep part load operation. The inter-blade cavitation vortex is a typical cavitation phenomenon observed at deep part load operation. However, its dynamic characteristics are insufficiently understood today. In an objective of revealing its characteristics, the present study introduces a novel visualization technique with instrumented guide vanes embedding the visualization devices, providing unprecedented views on the inter-blade cavitation vortex. The binary image processing technique enables the successful evaluation of the inter-blade cavitation vortex in the images. As a result, it is shown that the probability of the inter-blade cavitation development is significantly high close to the runner hub. Furthermore, the mean vortex line is calculated and the vortex region is estimated in the three-dimensional domain for the comparison with numerical simulation results. In addition, the on-board pressure measurements on a runner blade is conducted, and the influence of the inter-blade vortex on the pressure field is investigated. The analysis suggests that the presence of the inter-blade vortex can magnify the amplitude of pressure fluctuations especially on the blade suction side. Furthermore, the wall pressure difference between pressure and suction sides of the blade features partially low or negative values near the hub at the discharge region where the inter-blade vortex develops. This negative pressure difference on the blade wall suggests the development of a backflow region caused by the flow separation near the hub, which is closely related to the development of the inter-blade vortex. The development of the backflow region is confirmed by the numerical simulation, and the physical mechanisms of the inter-blade vortex development is, furthermore, discussed.

Gas turbine blade film cooling and blade tip heat transfer

NASA Astrophysics Data System (ADS)

Teng, Shuye

The detailed heat transfer coefficient and film cooling effectiveness distributions as well as the detailed coolant jet temperature profiles on the suction side of a gas turbine blade were measured using a transient liquid crystal image method and a traversing cold wire and thermocouple probe, respectively. The blade has only one row of film holes near the gill hole portion on the suction side of the blade. The hole geometries studied include standard cylindrical holes and holes with diffuser shaped exit portion (i.e. fanshaped holes and laidback fanshaped holes). Tests were performed on a five-blade linear cascade in a low-speed wind tunnel. The mainstream Reynolds number based on cascade exit velocity was 5.3 x 105. The upstream unsteady wakes were simulated using a spoke-wheel type wake generator. The wake Strouhal number was kept at 0 and 0.1. The coolant blowing ratio was varied from 0.4 to 1.2. Results show that both expanded holes have significantly improved thermal protection over the surface downstream of the ejection location, particularly at high blowing ratios. However, the expanded hole injections induce earlier boundary layer transition to turbulence and enhance heat transfer coefficients at the latter part of the blade suction surface. In general, the unsteady wake tends to reduce film cooling effectiveness. Measurements of detailed heat transfer coefficient distributions on a turbine blade tip were performed in the same wind tunnel facility as above. The central blade had a variable tip gap clearance. Measurements were made at three different tip gap clearances of about 1.1%, 2.1%, and 3% of the blade span. Static pressure distributions were measured in the blade mid-span and on the shroud surface. Detailed heat transfer coefficient distributions were measured on the blade tip surface. Results show that reduced tip clearance leads to reduced heat transfer coefficient over the blade tip surface. Results also show that reduced tip clearance tends to weaken the unsteady wake effect on blade tip heat transfer.

Impact force identification for composite helicopter blades using minimal sensing

NASA Astrophysics Data System (ADS)

Budde, Carson N.

In this research a method for online impact identification using minimal sensors is developed for rotor hubs with composite blades. Modal impact data and the corresponding responses are recorded at several locations to develop a frequency response function model for each composite blade on the rotor hub. The frequency response model for each blade is used to develop an impact identification algorithm which can be used to identify the location and magnitude of impacts. Impacts are applied in two experimental setups, including a four-blade spin test rig and a cantilevered full-sized composite blade. The impacts are estimated to have been applied at the correct location 92.3% of the time for static fiberglass blades, 97.4% of the time for static carbon fiber blades and 99.2% of the time for a full sized-static blade. The estimated location is assessed further and determined to have been estimated in the correct chord position 96.1% of the time for static fiberglass, 100% of the time for carbon fiber blades and 99.2% of the time for the full-sized blades. Projectile impacts are also applied statically and during rotation to the carbon fiber blades on the spin test rig at 57 and 83 RPM. The applied impacts can be located to the correct position 63.9%, 41.7% and 33.3% for the 0, 57 and 83 RPM speeds, respectively, while the correct chord location is estimated 100% of the time. The impact identification algorithm also estimates the force of an impact with an average percent difference of 4.64, 2.61 and 1.00 for static fiberglass, full sized, and carbon fiber blades, respectively. Using a load cell and work equations, the force of impact for a projectile fired from a dynamic firing setup is estimated at about 400 N. The average force measured for applied projectile impacts to the carbon fiber blades, rotating at 0, 57 and 83 RPM, is 368.8, 373.7 and 432.4 N, respectively.

Toward an Engineering Model for the Aerodynamic Forces Acting on Wind Turbine Blades in Quasisteady Standstill and Blade Installation Situations

NASA Astrophysics Data System (ADS)

Gaunaa, Mac; Heinz, Joachim; Skrzypiński, Witold

2016-09-01

The crossflow principle is one of the key elements used in engineering models for prediction of the aerodynamic loads on wind turbine blades in standstill or blade installation situations, where the flow direction relative to the wind turbine blade has a component in the direction of the blade span direction. In the present work, the performance of the crossflow principle is assessed on the DTU 10MW reference blade using extensive 3D CFD calculations. Analysis of the computational results shows that there is only a relatively narrow region in which the crossflow principle describes the aerodynamic loading well. In some conditions the deviation of the predicted loadings can be quite significant, having a large influence on for instance the integral aerodynamic moments around the blade centre of mass; which is very important for single blade installation applications. The main features of these deviations, however, have a systematic behaviour on all force components, which in this paper is employed to formulate the first version of an engineering correction method to the crossflow principle applicable for wind turbine blades. The new correction model improves the agreement with CFD results for the key aerodynamic loads in crossflow situations. The general validity of this model for other blade shapes should be investigated in subsequent works.

Dynamic response characteristics of dual flow-path integrally bladed rotors

NASA Astrophysics Data System (ADS)

Beck, Joseph A.; Brown, Jeffrey M.; Scott-Emuakpor, Onome E.; Cross, Charles J.; Slater, Joseph C.

2015-02-01

New turbine engine designs requiring secondary flow compression often look to dual flow-path integrally bladed rotors (DFIBRs) since these stages have the ability to perform work on the secondary, or bypassed, flow-field. While analogous to traditional integrally bladed rotor stages, DFIBR designs have many differences that result in unique dynamic response characteristics that must be understood to avoid fatigue. This work investigates these characteristics using reduced-order models (ROMs) that incorporate mistuning through perturbations to blade frequencies. This work provides an alternative to computationally intensive geometric-mistuning approaches for DFIBRs by utilizing tuned blade mode reductions and substructure coupling in cyclic coordinates. Free and forced response results are compared to full finite element model (FEM) solutions to determine if any errors are related to the reduced-order model formulation reduction methods. It is shown that DFIBRs have many more frequency veering regions than their single flow-path integrally blade rotor (IBR) counterparts. Modal families are shown to transition between system, inner-blade, and outer-blade motion. Furthermore, findings illustrate that while mode localization of traditional IBRs is limited to a single or small subset of blades, DFIBRs can have modal energy localized to either an inner- or outer-blade set resulting in many blades responding above tuned levels. Lastly, ROM forced response predictions compare well to full FEM predictions for the two test cases shown.

Development of a locally mass flux conservative computer code for calculating 3-D viscous flow in turbomachines

NASA Technical Reports Server (NTRS)

Walitt, L.

1982-01-01

The VANS successive approximation numerical method was extended to the computation of three dimensional, viscous, transonic flows in turbomachines. A cross-sectional computer code, which conserves mass flux at each point of the cross-sectional surface of computation was developed. In the VANS numerical method, the cross-sectional computation follows a blade-to-blade calculation. Numerical calculations were made for an axial annular turbine cascade and a transonic, centrifugal impeller with splitter vanes. The subsonic turbine cascade computation was generated in blade-to-blade surface to evaluate the accuracy of the blade-to-blade mode of marching. Calculated blade pressures at the hub, mid, and tip radii of the cascade agreed with corresponding measurements. The transonic impeller computation was conducted to test the newly developed locally mass flux conservative cross-sectional computer code. Both blade-to-blade and cross sectional modes of calculation were implemented for this problem. A triplet point shock structure was computed in the inducer region of the impeller. In addition, time-averaged shroud static pressures generally agreed with measured shroud pressures. It is concluded that the blade-to-blade computation produces a useful engineering flow field in regions of subsonic relative flow; and cross-sectional computation, with a locally mass flux conservative continuity equation, is required to compute the shock waves in regions of supersonic relative flow.

Impact resistance of composite fan blades

NASA Technical Reports Server (NTRS)

1974-01-01

Results are presented of a program to determine the impact resistance of composite fan blades subjected to foreign object damage (FOD) while operating under conditions simulating a short take-off and landing (STOL) engine at takeoff. The full-scale TF39 first-stage fan blade was chosen as the base design for the demonstration component since its configuration and operating tip speeds are similar to a typical STOL fan blade several composite configurations had already been designed and evaluated under previous programs. The first portion of the program was devoted toward fabricating and testing high impact resistant, aerodynamically acceptable composite blades which utilized only a single material system in any given blade. In order to increase the blade impact capability beyond this point, several mixed material (hybrid) designs were investigated using S-glass and Kevlar as well as boron and graphite fibers. These hybrid composite blades showed a marked improvement in resistance to bird impact over those blades made of a single composite material. The work conducted under this program has demonstrated substantial improvement in composite fan blades with respect to FOD resistance and has indicated that the hybrid design concept, which utilizes different types of fibers in various portions of a fan blade design depending on the particular requirements of the different areas and the characteristics of the different fibers involved, shows a significant improvement over those designs utilizing only one material system.

Effect of Spindle Parameters of Woodworking Band Saw on the AE Value of Crack Band Saw Blade in Compound Material Processing (1)

NASA Astrophysics Data System (ADS)

Gao, Jin-gui; Jiang, Zhao-fang; Luo, Lai-peng

2017-04-01

Taking the MJ3210A motion band saw as the research object, the AE value of the band saw blade vibration was obtained by analyzing the VIBSYS vibration signal acquisition and analysis software system in Beijing, and the change of the AE value of the band saw and the crack was found out. The experimental results show that in the MJ3210A sports car sawing machine, the band saw blade with width of 130 mm is used, and the AE value of the cracked band saw blade is well in the high band saw blade AE value. Under the best working condition of the band saw, the band saw blade AE If the value exceeds 104.7 dB (A) above, it means that the band saw blade has at least one crack length greater than 1.38 mm for the crack defect and the need to replace the band saw blade in time. Different species with saw blade of the AE value is different, white pine wood minimum, the largest oak wood; according to a variety of wood processing AE instrument value to determine the band saw blade crack to the situation; so as to fully rational use of band saw blade, The failure and the degree of development to find a new method.

Unsteady Turbine Blade and Tip Heat Transfer Due to Wake Passing

NASA Technical Reports Server (NTRS)

Ameri, Ali A.; Rigby, David L.; Steinthorsson, Erlendur; Heidmann, James; Fabian, John C.

2007-01-01

The geometry and the flow conditions of the first stage turbine blade of GE s E3 engine have been used to obtain the unsteady three-dimensional blade and tip heat transfer. The isothermal wall boundary condition was used. The effect of the upstream wake of the first stage vane was of interest and was simulated by provision of a gust type boundary condition upstream of the blades. A one blade periodic domain was used. The consequence of this choice was explored in a preliminary study which showed little difference in the time mean heat transfer between 1:1 and 2:3 vane/blade domains. The full three-dimensional computations are of the blade having a clearance gap of 2 percent the span. Comparison between the time averaged unsteady and steady heat transfer is provided. It is shown that there is a significant difference between the steady and time mean of unsteady blade heat transfer in localized regions. The differences on the suction side of the blade in the near hub and near tip regions were found to be rather significant. Steady analysis underestimated the blade heat transfer by as much as 20 percent as compared to the time average obtained from the unsteady analysis. As for the blade tip, the steady analysis and the unsteady analysis gave results to within 2 percent.

Feasibility study on a strain based deflection monitoring system for wind turbine blades

NASA Astrophysics Data System (ADS)

Lee, Kyunghyun; Aihara, Aya; Puntsagdash, Ganbayar; Kawaguchi, Takayuki; Sakamoto, Hiraku; Okuma, Masaaki

2017-01-01

The bending stiffness of the wind turbine blades has decreased due to the trend of wind turbine upsizing. Consequently, the risk of blades breakage by hitting the tower has increased. In order to prevent such incidents, this study proposes a deflection monitoring system that can be installed to already operating wind turbine's blades. The monitoring system is composed of an estimation algorithm to detect blade deflection and a wireless sensor network as a hardware equipment. As for the estimation method for blade deflection, a strain-based estimation algorithm and an objective function for optimal sensor arrangement are proposed. Strain-based estimation algorithm is using a linear correlation between strain and deflections, which can be expressed in a form of a transformation matrix. The objective function includes the terms of strain sensitivity and condition number of the transformation matrix between strain and deflection. In order to calculate the objective function, a simplified experimental model of the blade is constructed by interpolating the mode shape of a blade from modal testing. The interpolation method is effective considering a practical use to operating wind turbines' blades since it is not necessary to establish a finite element model of a blade. On the other hand, a sensor network with wireless connection with an open source hardware is developed. It is installed to a 300 W scale wind turbine and vibration of the blade on operation is investigated.

The Rene 150 directionally solidified superalloy turbine blades, volume 1

NASA Technical Reports Server (NTRS)

Deboer, G. J.

1981-01-01

Turbine blade design and analysis, preliminary Rene 150 system refinement, coating adaptation and evaluation, final Rene 150 system refinement, component-test blade production and evaluation, engine-test blade production, and engine test are discussed.

Improvement of centrifugal pump performance through addition of splitter blades on impeller pump

NASA Astrophysics Data System (ADS)

Kurniawan, Krisna Eka; Santoso, Budi; Tjahjana, Dominicus Danardono Dwi Prija

2018-02-01

The workable way to improve pump performance is to redesign or modify the impellers of centrifugal pump. The purpose of impeller pump modification is to improve pump efficiency, reduce cross flow, reduce secondary incidence flows, and decrease backflow areas at impeller outlets. Number blades and splitter blades in the impeller are three. The outlet blade angle is 20°, and the rotating speed of impeller is 2400 rpm. The added splitter blades variations are 0.25, 0.375, and 0.5 of the original blade length. The splitter blade placements are on the outer side of the impeller. The addition of splitter blades on the outer side of the impeller with 0.5L increases the pump head until 22% and the pump has 38.66% hydraulic efficiency. The best efficiency point of water flow rate pump (Qbep) was 3.02 × 10-3 m3/s.

Bionic Design of Wind Turbine Blade Based on Long-Eared Owl's Airfoil

PubMed Central

Li, Ming

2017-01-01

The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl's wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl's wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift. PMID:28243053

Simultaneous Optical Measurements of Axial and Tangential Steady-State Blade Deflections

NASA Technical Reports Server (NTRS)

Kurkov, Anatole P.; Dhadwal, Harbans S.

1999-01-01

Currently, the majority of fiber-optic blade instrumentation is being designed and manufactured by aircraft-engine companies for their own use. The most commonly employed probe for optical blade deflection measurements is the spot probe. One of its characteristics is that the incident spot on a blade is not fixed relative to the blade, but changes depending on the blade deformation associated with centrifugal and aerodynamic loading. While there are geometrically more complicated optical probe designs in use by different engine companies, this paper offers an alternate solution derived from a probe-mount design feature that allows one to change the probe axial position until the incident spot contacts either a leading or a trailing edge. By tracing the axial position of either blade edge one is essentially extending the deflection measurement to two dimensions, axial and tangential. The blade deflection measurements were obtained during a wind tunnel test of a fan prototype.

Performance of Savonius Blade Waterwheel with Variation of Blade Number

NASA Astrophysics Data System (ADS)

Sule, L.; Rompas, P. T. D.

2018-02-01

The utilization of water energy source is mainly used as a provider of electrical energy through hydroelectric power. The potential utilization of water flow energy is relatively small. The objective of this study is to know the best blade of Savonius waterwheel with various variables such as water discharge, blade number, and loading. The data used the efficiency of waterwheel, variation of blade number, variable water discharge, and loading in the shaft. The test results have shown that the performances of a top-water mill with the semicircular curve where the variation in the number of blades are 4, 6, and 8 at discharge and loading of 0.01587 m3/s and 1000 grams respectively were 9.945%, 13.929%, and 17.056% respectively. The blades number of 8 obtained the greatest performance. The more number of blades the greater the efficiency of the waterwheel Savonius.

Wind-tunnel evaluation of an advanced main-rotor blade design for a utility-class helicopter

NASA Technical Reports Server (NTRS)

Yeager, William T., Jr.; Mantay, Wayne R.; Wilbur, Matthew L.; Cramer, Robert G., Jr.; Singleton, Jeffrey D.

1987-01-01

An investigation was conducted in the Langley Transonic Dynamics Tunnel to evaluate differences between an existing utility-class main-rotor blade and an advanced-design main-rotor blade. The two rotor blade designs were compared with regard to rotor performance oscillatory pitch-link loads, and 4-per-rev vertical fixed-system loads. Tests were conducted in hover and over a range of simulated full-scale gross weights and density altitude conditions at advance ratios from 0.15 to 0.40. Results indicate that the advanced blade design offers performance improvements over the baseline blade in both hover and forward flight. Pitch-link oscillatory loads for the baseline rotor were more sensitive to the test conditions than those of the advanced rotor. The 4-per-rev vertical fixed-system load produced by the advanced blade was larger than that produced by the baseline blade at all test conditions.

X-ray position detector and implementation in a mirror pointing servo system

DOEpatents

Rabedeau, Thomas A.; Van Campen, Douglas G.; Stefan, Peter M.

2016-04-05

An X-ray beam position and stability detector is provided having a first metal blade collinear with a second metal blade, where an edge of the first metal blade is opposite an edge of the second metal blade, where the first metal blade edge and the second metal blade edge are disposed along a centerline with respect to each other, where the metal blades are capable of photoelectron emission when exposed to an x-ray beam, a metal coating on the metal blades that is capable of enhancing the photoelectron emission, or suppressing energy-resonant contaminants, or enhancing the photoelectron emission and suppressing energy-resonant contaminants, a background shielding element having an electrode capable of suppressing photoelectron emission from spurious x-rays not contained in an x-ray beam of interest, and a photoelectron emission detector having an amplifier capable of detecting the photoelectron emission as a current signal.

The effect of helicopter main rotor blade phasing and spacing on performance, blade loads, and acoustics

NASA Technical Reports Server (NTRS)

Gangwani, S. T.

1976-01-01

The performance, blade loads, and acoustic characteristics of a variable geometry rotor (VGR) system in forward flight and in a pullup maneuver were determined by the use of existing analytical programs. The investigation considered the independent effects of vertical separation of two three-bladed rotor systems as well as the effects of azimuthal spacing between the blades of the two rotors. The computations were done to determine the effects of these parameters on the performance, blade loads, and acoustic characteristics at two advance ratios in steady-state level flight and for two different g pullups at one advance ratio. To evaluate the potential benefits of the VGR concept in forward flight and pullup maneuvers, the results were compared as to performance, oscillatory blade loadings, vibratory forces transmitted to the fixed fuselage, and the rotor noise characteristics of the various VGR configurations with those of the conventional six-bladed rotor system.

Bionic Design of Wind Turbine Blade Based on Long-Eared Owl's Airfoil.

PubMed

Tian, Weijun; Yang, Zhen; Zhang, Qi; Wang, Jiyue; Li, Ming; Ma, Yi; Cong, Qian

2017-01-01

The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl's wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl's wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift.

Kinematics and constraints associated with swashplate blade pitch control

NASA Technical Reports Server (NTRS)

Leyland, Jane A.

1993-01-01

An important class of techniques to reduce helicopter vibration is based on using a Higher Harmonic controller to optimally define the Higher Harmonic blade pitch. These techniques typically require solution of a general optimization problem requiring the determination of a control vector which minimizes a performance index where functions of the control vector are subject to inequality constraints. Six possible constraint functions associated with swashplate blade pitch control were identified and defined. These functions constrain: (1) blade pitch Fourier Coefficients expressed in the Rotating System, (2) blade pitch Fourier Coefficients expressed in the Nonrotating System, (3) stroke of the individual actuators expressed in the Nonrotating System, (4) blade pitch expressed as a function of blade azimuth and actuator stroke, (5) time rate-of-change of the aforementioned parameters, and (6) required actuator power. The aforementioned constraints and the associated kinematics of swashplate blade pitch control by means of the strokes of the individual actuators are documented.

Method and apparatus for reducing cleaning blade wear

DOEpatents

Grannes, Steven G.; Rhoades, Charles A.; Hebbie, Terry L.

1992-01-01

An improved cleaning blade construction (10) for eliminating erosion troughs (6) in the upper surface (15) of a cleaning blade member (14) by introducing pressurized fluid through a pressure manifold chamber (16) formed in the upper surface (15) of the cleaning blade member (14). The pressurized fluid will prevent carryback material (7) from passing through a wear groove (6) formed in the cleaning blade member.

Cooling of Gas Turbines. 6 - Computed Temperature Distribution through Cross Section of Water-Cooled Turbine Blade

DTIC Science & Technology

1947-05-01

AERONAUTICS Figure 7. - Cross section of water-cooleä turbine blade showing location and size of seven coolant...Power Plants.~ Jet and~ Turbine ($) [SECTION. Turbines (I3) [CROSS DEFERENCES. Turbine blades - Thermal measurements (95350); Turbine blades ...section of water-cooled turbine blade FORG’N. TITLE: v.. ’V, ORIGINATING AGENCY. TRANSLATION. National Advisory Committee for Aeronautics

Integrated high efficiency blower apparatus for HVAC systems

DOEpatents

Liu, Xiaoyue; Weigman, Herman; Wang, Shixiao

2007-07-24

An integrated centrifugal blower wheel for a heating, ventilation and air conditioning (HVAC) blower unit includes a first blade support, a second blade support, and a plurality of S-shaped blades disposed between the first and second blade supports, wherein each of the S-shaped blades has a trailing edge bent in a forward direction with respect to a defined direction of rotation of the wheel.

Controlled laboratory testing of arthroscopic shaver systems: do blades, contact pressure, and speed influence their performance?

PubMed

Wieser, Karl; Erschbamer, Matthias; Neuhofer, Stefan; Ek, Eugene T; Gerber, Christian; Meyer, Dominik C

2012-10-01

The purposes of this study were (1) to establish a reproducible, standardized testing protocol to evaluate the performance of different shaver systems and blades in a controlled, laboratory setting, and (2) to determine the optimal use of different blades with respect to the influence of contact pressure and speed of blade rotation. A holding device was developed for reproducible testing of soft-tissue (tendon and meniscal) resection performance in a submerged environment, after loading of the shaver with interchangeable weights. The Karl Storz Powershaver S2 (Karl Storz, Tuttlingen, Germany), the Stryker Power Shaver System (Stryker, Kalamazoo, MI), and the Dyonics Power Shaver System (Smith & Nephew, Andover, MA) were tested, with different 5.5-mm shaver blades and varied contact pressure and rotation speed. For quality testing, serrated shaver blades were evaluated at 40× image magnification. Overall, more than 150 test cycles were performed. No significant differences could be detected between comparable blade types from different manufacturers. Shavers with a serrated inner blade and smooth outer blade performed significantly better than the standard smooth resectors (P < .001). Teeth on the outer layer of the blade did not lead to any further improvement of resection (P = .482). Optimal contact pressure ranged between 6 and 8 N, and optimal speed was found to be 2,000 to 2,500 rpm. Minimal blunting of the shaver blades occurred after soft-tissue resection; however, with bone resection, progressive blunting of the shaver blades was observed. Arthroscopic shavers can be tested in a controlled setting. The performance of the tested shaver types appears to be fairly independent of the manufacturer. For tendon resection, a smooth outer blade and serrated inner blade were optimal. This is one of the first established independent and quantitative assessments of arthroscopic shaver systems and blades. We believe that this study will assist the surgeon in choosing the optimal tool for the desired effect. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Design optimization for active twist rotor blades

NASA Astrophysics Data System (ADS)

Mok, Ji Won

This dissertation introduces the process of optimizing active twist rotor blades in the presence of embedded anisotropic piezo-composite actuators. Optimum design of active twist blades is a complex task, since it involves a rich design space with tightly coupled design variables. The study presents the development of an optimization framework for active helicopter rotor blade cross-sectional design. This optimization framework allows for exploring a rich and highly nonlinear design space in order to optimize the active twist rotor blades. Different analytical components are combined in the framework: cross-sectional analysis (UM/VABS), an automated mesh generator, a beam solver (DYMORE), a three-dimensional local strain recovery module, and a gradient based optimizer within MATLAB. Through the mathematical optimization problem, the static twist actuation performance of a blade is maximized while satisfying a series of blade constraints. These constraints are associated with locations of the center of gravity and elastic axis, blade mass per unit span, fundamental rotating blade frequencies, and the blade strength based on local three-dimensional strain fields under worst loading conditions. Through pre-processing, limitations of the proposed process have been studied. When limitations were detected, resolution strategies were proposed. These include mesh overlapping, element distortion, trailing edge tab modeling, electrode modeling and foam implementation of the mesh generator, and the initial point sensibility of the current optimization scheme. Examples demonstrate the effectiveness of this process. Optimization studies were performed on the NASA/Army/MIT ATR blade case. Even though that design was built and shown significant impact in vibration reduction, the proposed optimization process showed that the design could be improved significantly. The second example, based on a model scale of the AH-64D Apache blade, emphasized the capability of this framework to explore the nonlinear design space of complex planform. Especially for this case, detailed design is carried out to make the actual blade manufacturable. The proposed optimization framework is shown to be an effective tool to design high authority active twist blades to reduce vibration in future helicopter rotor blades.

Turbine Engine Hot Section Technology 1986

NASA Technical Reports Server (NTRS)

1986-01-01

The Turbine Engine Hot Section Technology (HOST) Project of the NASA Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine durability problems. Presentations were made concerning the hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes. The presentations were divided into six sessions: Instrumentation, Combustion, Turbine Heat Transfer, Structural Analysis, Fatigue and Fracture, and Surface Protection. Topics discussed included modeling of thermal and fluid-flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior of materials, stress-strain response, and life-prediction methods. Researchers from industry, academia, and government presented results of their work sponsored by the HOST project.

Striation patterns in serrated blade stabs to cartilage.

PubMed

Pounder, Derrick J; Reeder, Francesca D

2011-05-20

Stab wounds were made in porcine cartilage with 13 serrated knives, amongst which 4 were drop-point and 9 straight-spine; 9 coarsely serrated, 3 finely serrated and 1 with mixed pattern serrations. The walls of the stab tracks were cast with dental impression material, and the casts photographed together with the knife blades for comparison. All 13 serrated blades produced an "irregularly regular" pattern of striations on cartilage in all stabbings. Unusual and distinctive blade serration patterns produced equally distinctive wound striation patterns. A reference collection of striation patterns and corresponding blades might prove useful for striation pattern analysis. Drop-point blades produced similar striations to straight-spine blades except that the striations were not parallel but rather fan-shaped, converging towards the wound exit. The fan-shaped striation pattern characteristic of drop-point blades is explained by the initial lateral movement of the blade through the cartilage imposed by the presence of the drop point shape. It appears that the greater the overall angle of the drop point, the shorter the blade length over which the drop point occurs, and the closer the first serration is to the knife tip, the more obvious is the fan-shaped pattern. We anticipate that micro-irregularities producing individualising characteristics in non-serrated drop point blades, provided they were located at the tip opposite the drop point, should also show a fan-shaped pattern indicative of a drop point blade. The examination of the walls of stab wounds to cartilage represents an under-utilised source of forensic information to assist in knife identification. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Disposable stainless steel vs plastic laryngoscope blades among paramedics.

PubMed

Dos Santos, Frank D; Schnakofsky, Roberto; Cascio, Anthony; Liu, Junfeng; Merlin, Mark A

2011-07-01

Several studies have been published in the literature about intubation methods, but little is available on intubation equipment used in this setting. This is the first prehospital comparison of disposable plastic vs disposable stainless steel laryngoscope blades used by paramedics. The objective of this study was to compare prehospital intubation success rates on first attempt and overall number of attempts to obtain intubations using disposable plastic laryngoscopes blades vs disposable stainless steel laryngoscope blades. A retrospective prehospital cohort study was conducted during two 3-year periods. Two-way contingency table and χ(2) test were conducted to determine if there was a difference between the 2 types of blades. A proportional odds model with calculated 95% confidence interval (CI) and odd ratios were then calculated. A total of 2472 paramedic intubations were recorded over the 6-year period. The stainless steel single-use blades had a first attempt success rate of 88.9% vs 78.5% with plastic blades (P = .01; odds ratio, 1.94; 95% CI, 1.17-3.41). The stainless steel single-use laryngoscope blade had a lower number of attempts to successful intubation than the plastic blade (88.8% vs 74.3%, respectively) (P < .01; odds ratio, 1.64; 95% CI, 1.34-2.00). In the prehospital setting, stainless steel disposable blades were superior to plastic disposable blades in first attempt and overall number of attempts to intubation. Until further research is done, we recommend use of stainless steel blades for intubations in the prehospital setting by paramedics. Copyright © 2011 Elsevier Inc. All rights reserved.

Impact of current speed on mass flux to a model flexible seagrass blade

NASA Astrophysics Data System (ADS)

Lei, Jiarui; Nepf, Heidi

2016-07-01

Seagrass and other freshwater macrophytes can acquire nutrients from surrounding water through their blades. This flux may depend on the current speed (U), which can influence both the posture of flexible blades (reconfiguration) and the thickness of the flux-limiting diffusive layer. The impact of current speed (U) on mass flux to flexible blades of model seagrass was studied through a combination of laboratory flume experiments, numerical modeling and theory. Model seagrass blades were constructed from low-density polyethylene (LDPE), and 1, 2-dichlorobenzene was used as a tracer chemical. The tracer mass accumulation in the blades was measured at different unidirectional current speeds. A numerical model was used to estimate the transfer velocity (K) by fitting the measured mass uptake to a one-dimensional diffusion model. The measured transfer velocity was compared to predictions based on laminar and turbulent boundary layers developing over a flat plate parallel to flow, for which K∝U0.5 and ∝U, respectively. The degree of blade reconfiguration depended on the dimensionless Cauchy number, Ca, which is a function of both the blade stiffness and flow velocity. For large Ca, the majority of the blade was parallel to the flow, and the measured transfer velocity agreed with laminar boundary layer theory, K∝U0.5. For small Ca, the model blades remained upright, and the flux to the blade was diminished relative to the flat-plate model. A meadow-scale analysis suggests that the mass exchange at the blade scale may control the uptake at the meadow scale.

Fully Suspended, Five-Axis, Three-Magnetic-Bearing Dynamic Spin Rig With Forced Excitation

NASA Technical Reports Server (NTRS)

Morrison, Carlos R.; Provenza, Andrew; Kurkov, Anatole; Montague, Gerald; Duffy, Kirsten; Mehmed, Oral; Johnson, Dexter; Jansen, Ralph

2004-01-01

The Five-Axis, Three-Magnetic-Bearing Dynamic Spin Rig, a significant advancement in the Dynamic Spin Rig (DSR), is used to perform vibration tests of turbomachinery blades and components under rotating and nonrotating conditions in a vacuum. The rig has as its critical components three magnetic bearings: two heteropolar radial active magnetic bearings and a magnetic thrust bearing. The bearing configuration allows full vertical rotor magnetic suspension along with a feed-forward control feature, which will enable the excitation of various natural blade modes in bladed disk test articles. The theoretical, mechanical, electrical, and electronic aspects of the rig are discussed. Also presented are the forced-excitation results of a fully levitated, rotating and nonrotating, unbladed rotor and a fully levitated, rotating and nonrotating, bladed rotor in which a pair of blades was arranged 180 degrees apart from each other. These tests include the bounce mode excitation of the rotor in which the rotor was excited at the blade natural frequency of 144 Hz. The rotor natural mode frequency of 355 Hz was discerned from the plot of acceleration versus frequency. For nonrotating blades, a blade-tip excitation amplitude of approximately 100 g/A was achieved at the first-bending critical (approximately 144 Hz) and at the first-torsional and second-bending blade modes. A blade-tip displacement of 70 mils was achieved at the first-bending critical by exciting the blades at a forced-excitation phase angle of 908 relative to the vertical plane containing the blades while simultaneously rotating the shaft at 3000 rpm.