Science.gov

Sample records for engine system performance

  1. Performance Engineering as an Expert System.

    ERIC Educational Resources Information Center

    Harmon, Paul

    1984-01-01

    Considers three powerful techniques--heuristics, context trees, and search via backward chaining--that a knowledge engineer might employ to develop an expert system to automate performance engineering, i.e., the branch of instructional technology that focuses on the problems of business and industry. (MBR)

  2. The engineered barrier system: Performance issues

    SciTech Connect

    Pigford, T.H.

    1993-12-31

    The engineered barrier system (EBS) for geologic disposal of high-level waste may typically consist of the waste solid, a container, and a porous backfill. Whether the surrounding rock is part of the EBS is arguable, but the properties of the surrounding rock strongly affect the EBS performance. The EBS functions and performance issue are addressed.

  3. Hydraulic systems performance of Army engine oils

    SciTech Connect

    Marbach, H.W.; Lestz, S.J.

    1984-01-01

    A technical evaluation of qualified military specification lubricants was started by the U.S. Army Belvoir Research and Development Center and was performed at the U.S. Army Fuels and Lubricants Research Laboratory (AFLRL) located at Southwest Research Institute. This work was conducted to determine if such lubricants can be used as hydraulic fluids in Army Commercial Construction Equipment (CCE) and Selected Material Handling Equipment (SMHE). Sixteen military specification lubricants were extensively evaluated using twelve selected tests required by equipment manufacturers and one test developed by AFLRL in conjunction with John Deere. From the data developed, lubricants meeting Army specifications passed 88 percent of all the tests. It appears that the Army engine oils are good potential candidates for use as hydraulic and power transmission lubricants within the Army CCE/SMHE systems. Areas of concern include copper corrosion, wet brake/clutch frictional performance, and final drive gear wear.

  4. Engineered Barrier System performance requirements systems study report. Revision 02

    SciTech Connect

    Balady, M.A.

    1997-01-14

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.

  5. Systems engineering approach towards performance monitoring of emergency diesel generator

    NASA Astrophysics Data System (ADS)

    Ramli, Nurhayati; Yong-kwan, Lee

    2014-02-01

    Systems engineering is an interdisciplinary approach and means to enable the realization of successful systems. In this study, systems engineering approach towards the performance monitoring of Emergency Diesel Generator (EDG) is presented. Performance monitoring is part and parcel of predictive maintenance where the systems and components conditions can be detected before they result into failures. In an effort to identify the proposal for addressing performance monitoring, the EDG boundary has been defined. Based on the Probabilistic Safety Analysis (PSA) results and industry operating experiences, the most critical component is identified. This paper proposed a systems engineering concept development framework towards EDG performance monitoring. The expected output of this study is that the EDG reliability can be improved by the performance monitoring alternatives through the systems engineering concept development effort.

  6. Systems engineering approach towards performance monitoring of emergency diesel generator

    SciTech Connect

    Ramli, Nurhayati Yong-kwan, Lee

    2014-02-12

    Systems engineering is an interdisciplinary approach and means to enable the realization of successful systems. In this study, systems engineering approach towards the performance monitoring of Emergency Diesel Generator (EDG) is presented. Performance monitoring is part and parcel of predictive maintenance where the systems and components conditions can be detected before they result into failures. In an effort to identify the proposal for addressing performance monitoring, the EDG boundary has been defined. Based on the Probabilistic Safety Analysis (PSA) results and industry operating experiences, the most critical component is identified. This paper proposed a systems engineering concept development framework towards EDG performance monitoring. The expected output of this study is that the EDG reliability can be improved by the performance monitoring alternatives through the systems engineering concept development effort.

  7. Predicted performance of an integrated modular engine system

    NASA Technical Reports Server (NTRS)

    Binder, Michael; Felder, James L.

    1993-01-01

    Space vehicle propulsion systems are traditionally comprised of a cluster of discrete engines, each with its own set of turbopumps, valves, and a thrust chamber. The Integrated Modular Engine (IME) concept proposes a vehicle propulsion system comprised of multiple turbopumps, valves, and thrust chambers which are all interconnected. The IME concept has potential advantages in fault-tolerance, weight, and operational efficiency compared with the traditional clustered engine configuration. The purpose of this study is to examine the steady-state performance of an IME system with various components removed to simulate fault conditions. An IME configuration for a hydrogen/oxygen expander cycle propulsion system with four sets of turbopumps and eight thrust chambers has been modeled using the Rocket Engine Transient Simulator (ROCETS) program. The nominal steady-state performance is simulated, as well as turbopump thrust chamber and duct failures. The impact of component failures on system performance is discussed in the context of the system's fault tolerant capabilities.

  8. Analysis of Aurora's Performance Simulation Engine for Three Systems

    SciTech Connect

    Freeman, Janine; Simon, Joseph

    2015-07-07

    Aurora Solar Inc. is building a cloud-based optimization platform to automate the design, engineering, and permit generation process of solar photovoltaic (PV) installations. They requested that the National Renewable Energy Laboratory (NREL) validate the performance of the PV system performance simulation engine of Aurora Solar’s solar design platform, Aurora. In previous work, NREL performed a validation of multiple other PV modeling tools 1, so this study builds upon that work by examining all of the same fixed-tilt systems with available module datasheets that NREL selected and used in the aforementioned study. Aurora Solar set up these three operating PV systems in their modeling platform using NREL-provided system specifications and concurrent weather data. NREL then verified the setup of these systems, ran the simulations, and compared the Aurora-predicted performance data to measured performance data for those three systems, as well as to performance data predicted by other PV modeling tools.

  9. Large liquid rocket engine transient performance simulation system

    NASA Technical Reports Server (NTRS)

    Mason, J. R.; Southwick, R. D.

    1989-01-01

    Phase 1 of the Rocket Engine Transient Simulation (ROCETS) program consists of seven technical tasks: architecture; system requirements; component and submodel requirements; submodel implementation; component implementation; submodel testing and verification; and subsystem testing and verification. These tasks were completed. Phase 2 of ROCETS consists of two technical tasks: Technology Test Bed Engine (TTBE) model data generation; and system testing verification. During this period specific coding of the system processors was begun and the engineering representations of Phase 1 were expanded to produce a simple model of the TTBE. As the code was completed, some minor modifications to the system architecture centering on the global variable common, GLOBVAR, were necessary to increase processor efficiency. The engineering modules completed during Phase 2 are listed: INJTOO - main injector; MCHBOO - main chamber; NOZLOO - nozzle thrust calculations; PBRNOO - preburner; PIPE02 - compressible flow without inertia; PUMPOO - polytropic pump; ROTROO - rotor torque balance/speed derivative; and TURBOO - turbine. Detailed documentation of these modules is in the Appendix. In addition to the engineering modules, several submodules were also completed. These submodules include combustion properties, component performance characteristics (maps), and specific utilities. Specific coding was begun on the system configuration processor. All functions necessary for multiple module operation were completed but the SOLVER implementation is still under development. This system, the Verification Checkout Facility (VCF) allows interactive comparison of module results to store data as well as provides an intermediate checkout of the processor code. After validation using the VCF, the engineering modules and submodules were used to build a simple TTBE.

  10. Large liquid rocket engine transient performance simulation system

    NASA Technical Reports Server (NTRS)

    Mason, J. R.; Southwick, R. D.

    1991-01-01

    A simulation system, ROCETS, was designed and developed to allow cost-effective computer predictions of liquid rocket engine transient performance. The system allows a user to generate a simulation of any rocket engine configuration using component modules stored in a library through high-level input commands. The system library currently contains 24 component modules, 57 sub-modules and maps, and 33 system routines and utilities. FORTRAN models from other sources can be operated in the system upon inclusion of interface information on comment cards. Operation of the simulation is simplified for the user by run, execution, and output processors. The simulation system makes available steady-state trim balance, transient operation, and linear partial generation. The system utilizes a modern equation solver for efficient operation of the simulations. Transient integration methods include integral and differential forms for the trapezoidal, first order Gear, and second order Gear corrector equations. A detailed technology test bed engine (TTBE) model was generated to be used as the acceptance test of the simulation system. The general level of model detail was that reflected in the Space Shuttle Main Engine DTM. The model successfully obtained steady-state balance in main stage operation and simulated throttle transients, including engine starts and shutdown. A NASA FORTRAN control model was obtained, ROCETS interface installed in comment cards, and operated with the TTBE model in closed-loop transient mode.

  11. Method and system for monitoring and displaying engine performance parameters

    NASA Technical Reports Server (NTRS)

    Abbott, Terence S. (Inventor); Person, Jr., Lee H. (Inventor)

    1991-01-01

    The invention is a method and system for monitoring and directly displaying the actual thrust produced by a jet aircraft engine under determined operating conditions and the available thrust and predicted (commanded) thrust of a functional model of an ideal engine under the same determined operating conditions. A first set of actual value output signals representative of a plurality of actual performance parameters of the engine under the determined operating conditions is generated and compared with a second set of predicted value output signals representative of the predicted value of corresponding performance parameters of a functional model of the engine under the determined operating conditions to produce a third set of difference value output signals within a range of normal, caution, or warning limit values. A thrust indicator displays when any one of the actual value output signals is in the warning range while shaping function means shape each of the respective difference output signals as each approaches the limit of the respective normal, caution, and warning range limits.

  12. Energy Efficient Engine: Control system component performance report

    NASA Technical Reports Server (NTRS)

    Beitler, R. S.; Bennett, G. W.

    1984-01-01

    An Energy Efficient Engine (E3) program was established to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, General Electric designed and tested a new engine. The design, fabrication, bench and engine testing of the Full Authority Digital Electronic Control (FADEC) system used for controlling the E3 Demonstrator Engine is described. The system design was based on many of the proven concepts and component designs used on the General Electric family of engines. One significant difference is the use of the FADEC in place of hydromechanical computation currently used.

  13. Integrated modeling tool for performance engineering of complex computer systems

    NASA Technical Reports Server (NTRS)

    Wright, Gary; Ball, Duane; Hoyt, Susan; Steele, Oscar

    1989-01-01

    This report summarizes Advanced System Technologies' accomplishments on the Phase 2 SBIR contract NAS7-995. The technical objectives of the report are: (1) to develop an evaluation version of a graphical, integrated modeling language according to the specification resulting from the Phase 2 research; and (2) to determine the degree to which the language meets its objectives by evaluating ease of use, utility of two sets of performance predictions, and the power of the language constructs. The technical approach followed to meet these objectives was to design, develop, and test an evaluation prototype of a graphical, performance prediction tool. The utility of the prototype was then evaluated by applying it to a variety of test cases found in the literature and in AST case histories. Numerous models were constructed and successfully tested. The major conclusion of this Phase 2 SBIR research and development effort is that complex, real-time computer systems can be specified in a non-procedural manner using combinations of icons, windows, menus, and dialogs. Such a specification technique provides an interface that system designers and architects find natural and easy to use. In addition, PEDESTAL's multiview approach provides system engineers with the capability to perform the trade-offs necessary to produce a design that meets timing performance requirements. Sample system designs analyzed during the development effort showed that models could be constructed in a fraction of the time required by non-visual system design capture tools.

  14. Engineering Development of Coal-Fired High Performance Power Systems

    SciTech Connect

    2000-12-31

    This report presents work carried out under contract DE-AC22-95PC95144 ''Engineering Development of Coal-Fired High Performance Systems Phase II and III.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: thermal efficiency (HHV) {ge} 47% NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) coal providing {ge} 65% of heat input all solid wastes benign cost of electricity {le}{le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site-specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: Task 2.2 HITAF Air Heaters

  15. Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance

    SciTech Connect

    DK Ezekoye; Matt Hall; Ron Matthews

    2005-08-01

    This Final Technical Report discusses the progress that was made on the experimental and numerical tasks over the duration of this project. The primary objectives of the project were to (1) develop an improved understanding of the spark ignition process, and (2) develop the railplug as an improved ignitor for large bore stationary natural gas engines. We performed fundamental experiments on the physical processes occurring during spark ignition and used the results from these experiments to aid our development of the most complete model of the spark ignition process ever devised. The elements in this model include (1) the dynamic response of the ignition circuit, (2) a chemical kinetics mechanism that is suitable for the reactions that occur in the plasma, (3) conventional flame propagation kinetics, and (4) a multi-dimensional formulation so that bulk flow through the spark gap can be incorporated. This model (i.e., a Fortran code that can be used as a subroutine within an engine modeling code such as KIVA) can be obtained from Prof. Ron Matthews at rdmatt{at}mail.utexas.edu or Prof. DK Ezekoye at dezekoye{at}mail.utexas.edu. Fundamental experiments, engine experiments, and modeling tasks were used to help develop the railplug as a new ignitor for large bore natural gas engines. As the result of these studies, we developed a railplug that could extend the Lean Stability Limit (LSL) of an engine operating at full load on natural gas from {phi} = 0.59 for operation on spark plugs down to {phi} = 0.53 using railplugs with the same delivered energy (0.7 J). However, this delivered energy would rapidly wear out the spark plug. For a conventional delivered energy (<0.05 J), the LSL is {phi} = 0.63 for a spark plug. Further, using a permanent magnet to aid the plasma movement, the LSL was extended to {phi} = 0.54 for a railplug with a delivered energy of only 0.15 J/shot, a typical discharge energy for commercial capacitive discharge ignition systems. Here, it should be

  16. Performance of Scramjet Engine with MHD Energy Bypass System

    NASA Astrophysics Data System (ADS)

    Kaminaga, Susumu; Tomioka, Sadatake; Yamasaki, Hiroyuki

    Flow behavior and thrust performance of MHD energy bypass scramjet engine was examined numerically. MHD generator was placed at the isolator to enhance the flow compression. Kinetic energy was converted to electrical energy in the MHD generator. Extracted electrical energy was consumed at the MHD accelerator placed at the downstream of the combustor. When MHD energy bypass system was used, the flow was decelerated and compressed in the MHD generator. Effect of velocity and Mach number on wall friction was analyzed and decrease of friction force was pointed out. Also, high pressure in the combustor resulted in increase of pressure contribution to net thrust. Despite of positive effects, decelerating Lorentz force in the MHD generator was comparably large and no significant difference in net thrust performance is observed.

  17. Quiet Clean Short-Haul Experimental Engine (QCSEE) Over-The-Wing (OTW) propulsion system test report. Volume 2: Aerodynamics and performance. [engine performance tests to define propulsion system performance on turbofan engines

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design and testing of the over the wing engine, a high bypass, geared turbofan engine, are discussed. The propulsion system performance is examined for uninstalled performance and installed performance. The fan aerodynamic performance and the D nozzle and reverser thrust performance are evaluated.

  18. System integration and performance of the EUV engineering test stand

    SciTech Connect

    Tichenor, Daniel A.; Ray-Chaudhuri, Avijit K.; Replogle, William C.; Stulen, Richard H.; Kubiak, Glenn D.; Rockett, Paul D.; Klebanoff, Leonard E.; Jefferson, Karen L.; Leung, Alvin H.; Wronosky, John B.; Hale, Layton C.; Chapman, Henry N.; Taylor, John S.; Folta, James A.; Montcalm, Claude; Soufli, Regina; Spiller, Eberhard; Blaedel, Kenneth; Sommargren, Gary E.; Sweeney, Donald W.; Naulleau, Patrick; Goldberg, Kenneth A.; Gullikson, Eric M.; Bokor, Jeffrey; Batson, Phillip J.; Attwood, David T.; Jackson, Keith H.; Hector, Scott D.; Gwyn, Charles W.; Yan, Pei-Yang; Yan, P.

    2001-03-01

    The Engineering Test Stand (ETS) is a developmental lithography tool designed to demonstrate full-field EUV imaging and provide data for commercial-tool development. In the first phase of integration, currently in progress, the ETS is configured using a developmental projection system, while fabrication of an improved projection system proceeds in parallel. The optics in the second projection system have been fabricated to tighter specifications for improved resolution and reduced flare. The projection system is a 4-mirror, 4x-reduction, ring-field design having a numeral aperture of 0.1, which supports 70 nm resolution at a k{sub 1} of 0.52. The illuminator produces 13.4 nm radiation from a laser-produced plasma, directs the radiation onto an arc-shaped field of view, and provides an effective fill factor at the pupil plane of 0.7. The ETS is designed for full-field images in step-and-scan mode using vacuum-compatible, magnetically levitated, scanning stages. This paper describes system performance observed during the first phase of integration, including static resist images of 100 nm isolated and dense features.

  19. Hydrazine engine start system air start performance and controls sizing

    SciTech Connect

    Johnson, A.T.

    1992-01-01

    Hydrazine has been used as an energy source in many applications to fuel in-flight main engine starting. In a current application, an existing hydrazine engine start system (ESS) design was adapted to meet new fuel control requirements. This paper presents a brief system description, historical context, and the motivating factors for the hydrazine controls changes and three case studies of controls design and analysis from the ESS program. 4 refs.

  20. Systems study on engineered barriers: barrier performance analysis

    SciTech Connect

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed.

  1. New model performance index for engineering design of control systems

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Performance index includes a model representing linear control-system design specifications. Based on a geometric criterion for approximation of the model by the actual system, the index can be interpreted directly in terms of the desired system response model without actually having the model's time response.

  2. Performance of the engineering analysis and data system 2 common file system

    NASA Technical Reports Server (NTRS)

    Debrunner, Linda S.

    1993-01-01

    The Engineering Analysis and Data System (EADS) was used from April 1986 to July 1993 to support large scale scientific and engineering computation (e.g. computational fluid dynamics) at Marshall Space Flight Center. The need for an updated system resulted in a RFP in June 1991, after which a contract was awarded to Cray Grumman. EADS II was installed in February 1993, and by July 1993 most users were migrated. EADS II is a network of heterogeneous computer systems supporting scientific and engineering applications. The Common File System (CFS) is a key component of this system. The CFS provides a seamless, integrated environment to the users of EADS II including both disk and tape storage. UniTree software is used to implement this hierarchical storage management system. The performance of the CFS suffered during the early months of the production system. Several of the performance problems were traced to software bugs which have been corrected. Other problems were associated with hardware. However, the use of NFS in UniTree UCFM software limits the performance of the system. The performance issues related to the CFS have led to a need to develop a greater understanding of the CFS organization. This paper will first describe the EADS II with emphasis on the CFS. Then, a discussion of mass storage systems will be presented, and methods of measuring the performance of the Common File System will be outlined. Finally, areas for further study will be identified and conclusions will be drawn.

  3. Systems Engineering Knowledge Asset (SEKA) Management for Higher Performing Engineering Teams: People, Process and Technology toward Effective Knowledge-Workers

    ERIC Educational Resources Information Center

    Shelby, Kenneth R., Jr.

    2013-01-01

    Systems engineering teams' value-creation for enterprises is slower than possible due to inefficiencies in communication, learning, common knowledge collaboration and leadership conduct. This dissertation outlines the surrounding people, process and technology dimensions for higher performing engineering teams. It describes a true experiment…

  4. Engineering performance metrics

    NASA Astrophysics Data System (ADS)

    Delozier, R.; Snyder, N.

    1993-03-01

    Implementation of a Total Quality Management (TQM) approach to engineering work required the development of a system of metrics which would serve as a meaningful management tool for evaluating effectiveness in accomplishing project objectives and in achieving improved customer satisfaction. A team effort was chartered with the goal of developing a system of engineering performance metrics which would measure customer satisfaction, quality, cost effectiveness, and timeliness. The approach to developing this system involved normal systems design phases including, conceptual design, detailed design, implementation, and integration. The lessons teamed from this effort will be explored in this paper. These lessons learned may provide a starting point for other large engineering organizations seeking to institute a performance measurement system accomplishing project objectives and in achieving improved customer satisfaction. To facilitate this effort, a team was chartered to assist in the development of the metrics system. This team, consisting of customers and Engineering staff members, was utilized to ensure that the needs and views of the customers were considered in the development of performance measurements. The development of a system of metrics is no different than the development of any type of system. It includes the steps of defining performance measurement requirements, measurement process conceptual design, performance measurement and reporting system detailed design, and system implementation and integration.

  5. Engineering performance metrics

    SciTech Connect

    DeLozier, R. ); Snyder, N. )

    1993-03-31

    Implementation of a Total Quality Management (TQM) approach to engineering work required the development of a system of metrics which would serve as a meaningful msinagement tool for evaluating effectiveness in accomplishing project objectives and in achieving improved customer satisfaction. A team effort was chartered with the goal of developing a system of engineering performance metrics which would measure customer satisfaction, quality, cost effectiveness, and timeliness. The approach to developing this system involved normal systems design phases including, conceptual design, detailed design, implementation, and integration. The lessons teamed from this effort will be explored in this paper. These lessons teamed may provide a starting point for other large engineering organizations seeking to institute a performance measurement system accomplishing project objectives and in achieving improved customer satisfaction. To facilitate this effort, a team was chartered to assist in the development of the metrics system. This team, consisting of customers and Engineering staff members, was utilized to ensure that the needs and views of the customers were considered in the development of performance measurements. The development of a system of metrics is no different than the development of any type of system. It includes the steps of defining performance measurement requirements, measurement process conceptual design, performance measurement and reporting system detailed design, and system implementation and integration.

  6. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    PubMed

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced. PMID:19683439

  7. Effect of Propeller on Engine Cooling System Drag and Performance

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Corsiglia, Victor R.; Barlow, Philip R.

    1982-01-01

    The pressure recovery of incoming cooling air and the drag associated with engine cooling of a typical general aviation twin-engine aircraft was Investigated experimentally. The semispan model was mounted vertically in the 40 x 80-Foot Wind Tunnel at Ames Research Center. The propeller was driven by an electric motor to provide thrust with low vibration levels for the cold-now configuration. It was found that the propeller slip-stream reduces the frontal air spillage around the blunt nacelle shape. Consequently, this slip-stream effect promotes flow reattachment at the rear section of the engine nacelle and improves inlet pressure recovery. These effects are most pronounced at high angles of attack; that is, climb condition. For the cruise condition those improvements were more moderate.

  8. The performance of solar thermal electric power systems employing small heat engines

    NASA Technical Reports Server (NTRS)

    Pons, R. L.

    1980-01-01

    The paper presents a comparative analysis of small (10 to 100 KWe) heat engines for use with a solar thermal electric system employing the point-focusing, distributed receiver (PF-DR) concept. Stirling, Brayton, and Rankine cycle engines are evaluated for a nominal overall system power level of 1 MWe, although the concept is applicable to power levels up to at least 10 MWe. Multiple concentrators are electrically connected to achieve the desired plant output. Best performance is achieved with the Stirling engine, resulting in a system Levelized Busbar Energy Cost of just under 50 mills/kWH and a Capital Cost of $900/kW, based on the use of mass-produced components. Brayton and Rankine engines show somewhat less performance but are viable alternatives with particular benefits for special applications. All three engines show excellent performance for the small community application.

  9. The performance of solar thermal electric power systems employing small heat engines

    NASA Astrophysics Data System (ADS)

    Pons, R. L.

    1980-02-01

    The paper presents a comparative analysis of small (10 to 100 KWe) heat engines for use with a solar thermal electric system employing the point-focusing, distributed receiver (PF-DR) concept. Stirling, Brayton, and Rankine cycle engines are evaluated for a nominal overall system power level of 1 MWe, although the concept is applicable to power levels up to at least 10 MWe. Multiple concentrators are electrically connected to achieve the desired plant output. Best performance is achieved with the Stirling engine, resulting in a system Levelized Busbar Energy Cost of just under 50 mills/kWH and a Capital Cost of $900/kW, based on the use of mass-produced components. Brayton and Rankine engines show somewhat less performance but are viable alternatives with particular benefits for special applications. All three engines show excellent performance for the small community application.

  10. Progress in waste package and engineered barrier system performance assessment and design

    SciTech Connect

    Van Luik, A.; Harrison, D.

    1993-12-31

    As part of the U.S. Department of Energy`s evaluation of site suitability for a potential high-level radioactive waste repository, long-term interactions between the engineered barrier system and the site must be determined. This requires a waste-package/engineered-system design, a description of the environment around the emplacement zone, and models that simulate operative processes describing these engineered/natural systems interactions. Candidate designs are being evaluated, including a more robust, multi-barrier waste package, and a drift emplacement mode. Tools for evaluating designs, and emplacement mode are the currently available waste-package/engineered-system performance assessment codes development for the project. For assessments that support site suitability, environmental impact, or licensing decisions, more capable codes are needed. Code capability requirements are being written, and existing codes are to be evaluated against those requirements. Recommendations are being made to focus waste-packaging/engineered-system code-development.

  11. Layered Systems Engineering Engines

    NASA Technical Reports Server (NTRS)

    Breidenthal, Julian C.; Overman, Marvin J.

    2009-01-01

    A notation is described for depicting the relationships between multiple, contemporaneous systems engineering efforts undertaken within a multi-layer system-of-systems hierarchy. We combined the concepts of remoteness of activity from the end customer, depiction of activity on a timeline, and data flow to create a new kind of diagram which we call a "Layered Vee Diagram." This notation is an advance over previous notations because it is able to be simultaneously precise about activity, level of granularity, product exchanges, and timing; these advances provide systems engineering managers a significantly improved ability to express and understand the relationships between many systems engineering efforts. Using the new notation, we obtain a key insight into the relationship between project duration and the strategy selected for chaining the systems engineering effort between layers, as well as insights into the costs, opportunities, and risks associated with alternate chaining strategies.

  12. Systems Engineering

    NASA Technical Reports Server (NTRS)

    Pellerano, Fernando

    2015-01-01

    This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

  13. L-Band System Engineering - Concepts of Use, Systems Performance Requirements, and Architecture

    NASA Technical Reports Server (NTRS)

    Henriksen, Stephen; Zelkin, Natalie

    2011-01-01

    This document is being provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-band and L-band Communications Standard Development. Task 7 was motivated by the five year technology assessment performed for the Federal Aviation Administration (FAA) under the joint FAA-EUROCONTROL cooperative research Action Plan (AP-17), also known as the Future Communications Study (FCS). It was based on direction provided by the FAA project-level agreement (PLA FY09_G1M.02-02v1) for "New ATM Requirements-Future Communications." Task 7 was separated into two distinct subtasks, each aligned with specific work elements and deliverable items. Subtask 7-1 addressed C-band airport surface data communications standards development, systems engineering, test bed development, and tests/demonstrations to establish operational capability for what is now referred to as the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2, which is the subject of this report, focused on preliminary systems engineering and support of joint FAA/EUROCONTROL development and evaluation of a future L-band (960 to 1164 MHz) air/ground (A/G) communication system known as the L-band digital aeronautical communications system (L-DACS), which was defined during the FCS. The proposed L-DACS will be capable of providing ATM services in continental airspace in the 2020+ timeframe. Subtask 7-2 was performed in two phases. Phase I featured development of Concepts of Use, high level functional analyses, performance of initial L-band system safety and security risk assessments, and development of high level requirements and architectures. It also included the aforementioned support of joint L-DACS development and evaluation, including inputs to L-DACS design specifications. Phase II provided a refinement of the systems engineering activities performed during Phase I, along

  14. Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.

    1979-01-01

    The paper describes the computational techniques employed in determining the optimal propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements. The computer programs used to perform calculations for all the factors that enter into the selection process of determining the optimum combinations of airplanes and engines are examined. Attention is given to the description of the computer codes including NNEP, WATE, LIFCYC, INSTAL, and POD DRG. A process is illustrated by which turbine engines can be evaluated as to fuel consumption, engine weight, cost and installation effects. Examples are shown as to the benefits of variable geometry and of the tradeoff between fuel burned and engine weights. Future plans for further improvements in the analytical modeling of engine systems are also described.

  15. Predicted performance benefits of an adaptive digital engine control system of an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Myers, L. P.; Ray, R. J.

    1985-01-01

    The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrating engine-airframe control systems. Currently this is accomplished on the NASA Ames Research Center's F-15 airplane. The two control modes used to implement the systems are an integrated flightpath management mode and in integrated adaptive engine control system (ADECS) mode. The ADECS mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the available engine stall margin are continually computed. The excess stall margin is traded for thrust. The predicted increase in engine performance due to the ADECS mode is presented in this report.

  16. Predicted performance benefits of an adaptive digital engine control system on an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Myers, L. P.; Ray, R. J.

    1985-01-01

    The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrating engine-airframe control systems. Currently this is accomplished on the NASA Ames Research Center's F-15 airplane. The two control modes used to implement the systems are an integrated flightpath management mode and an integrated adaptive engine control system (ADECS) mode. The ADECS mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the available engine stall margin are continually computed. The excess stall margin is traded for thrust. The predicted increase in engine performance due to the ADECS mode is presented in this report.

  17. Autonomous Propulsion System Technology Being Developed to Optimize Engine Performance Throughout the Lifecycle

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    2004-01-01

    The goal of the Autonomous Propulsion System Technology (APST) project is to reduce pilot workload under both normal and anomalous conditions. Ongoing work under APST develops and leverages technologies that provide autonomous engine monitoring, diagnosing, and controller adaptation functions, resulting in an integrated suite of algorithms that maintain the propulsion system's performance and safety throughout its life. Engine-to-engine performance variation occurs among new engines because of manufacturing tolerances and assembly practices. As an engine wears, the performance changes as operability limits are reached. In addition to these normal phenomena, other unanticipated events such as sensor failures, bird ingestion, or component faults may occur, affecting pilot workload as well as compromising safety. APST will adapt the controller as necessary to achieve optimal performance for a normal aging engine, and the safety net of APST algorithms will examine and interpret data from a variety of onboard sources to detect, isolate, and if possible, accommodate faults. Situations that cannot be accommodated within the faulted engine itself will be referred to a higher level vehicle management system. This system will have the authority to redistribute the faulted engine's functionality among other engines, or to replan the mission based on this new engine health information. Work is currently underway in the areas of adaptive control to compensate for engine degradation due to aging, data fusion for diagnostics and prognostics of specific sensor and component faults, and foreign object ingestion detection. In addition, a framework is being defined for integrating all the components of APST into a unified system. A multivariable, adaptive, multimode control algorithm has been developed that accommodates degradation-induced thrust disturbances during throttle transients. The baseline controller of the engine model currently being investigated has multiple control

  18. System analysis of a piston steam engine employing the uniflow principle, a study in optimized performance

    NASA Technical Reports Server (NTRS)

    Peoples, J. A.

    1975-01-01

    Results are reported which were obtained from a mathematical model of a generalized piston steam engine configuration employing the uniflow principal. The model accounted for the effects of clearance volume, compression work, and release volume. A simple solution is presented which characterizes optimum performance of the steam engine, based on miles per gallon. Development of the mathematical model is presented. The relationship between efficiency and miles per gallon is developed. An approach to steam car analysis and design is presented which has purpose rather than lucky hopefulness. A practical engine design is proposed which correlates to the definition of the type engine used. This engine integrates several system components into the engine structure. All conclusions relate to the classical Rankine Cycle.

  19. Engine Performance (Section C: Emission Control Systems). Auto Mechanics Curriculum Guide. Module 3. Instructor's Guide.

    ERIC Educational Resources Information Center

    Rains, Larry

    This engine performance (emission control systems) module is one of a series of competency-based modules in the Missouri Auto Mechanics Curriculum Guide. Topics of this module's five units are: positive crankcase ventilation (PCV) and evaporative emission control systems; exhaust gas recirculation (EGR); air injection and catalytic converters;…

  20. Effects of visual and motion simulation cueing systems on pilot performance during takeoffs with engine failures

    NASA Technical Reports Server (NTRS)

    Parris, B. L.; Cook, A. M.

    1978-01-01

    Data are presented that show the effects of visual and motion during cueing on pilot performance during takeoffs with engine failures. Four groups of USAF pilots flew a simulated KC-135 using four different cueing systems. The most basic of these systems was of the instrument-only type. Visual scene simulation and/or motion simulation was added to produce the other systems. Learning curves, mean performance, and subjective data are examined. The results show that the addition of visual cueing results in significant improvement in pilot performance, but the combined use of visual and motion cueing results in far better performance.

  1. Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.

    1980-01-01

    The computational techniques are described which are utilized at Lewis Research Center to determine the optimum propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements. Cycle performance, and engine weight can be calculated along with costs and installation effects as opposed to fuel consumption alone. Almost any conceivable turbine engine cycle can be studied. These computer codes are: NNEP, WATE, LIFCYC, INSTAL, and POD DRG. Examples are given to illustrate how these computer techniques can be applied to analyze and optimize propulsion system fuel consumption, weight and cost for representative types of aircraft and missions.

  2. Performance Analysis of Stirling Engine-Driven Vapor Compression Heat Pump System

    NASA Astrophysics Data System (ADS)

    Kagawa, Noboru

    Stirling engine-driven vapor compression systems have many unique advantages including higher thermal efficiencies, preferable exhaust gas characteristics, multi-fuel usage, and low noise and vibration which can play an important role in alleviating environmental and energy problems. This paper introduces a design method for the systems based on reliable mathematical methods for Stirling and Rankin cycles using reliable thermophysical information for refrigerants. The model deals with a combination of a kinematic Stirling engine and a scroll compressor. Some experimental coefficients are used to formulate the model. The obtained results show the performance behavior in detail. The measured performance of the actual system coincides with the calculated results. Furthermore, the calculated results clarify the performance using alternative refrigerants for R-22.

  3. Performance evaluation of the Engineering Analysis and Data Systems (EADS) 2

    NASA Technical Reports Server (NTRS)

    Debrunner, Linda S.

    1994-01-01

    The Engineering Analysis and Data System (EADS)II (1) was installed in March 1993 to provide high performance computing for science and engineering at Marshall Space Flight Center (MSFC). EADS II increased the computing capabilities over the existing EADS facility in the areas of throughput and mass storage. EADS II includes a Vector Processor Compute System (VPCS), a Virtual Memory Compute System (CFS), a Common Output System (COS), as well as Image Processing Station, Mini Super Computers, and Intelligent Workstations. These facilities are interconnected by a sophisticated network system. This work considers only the performance of the VPCS and the CFS. The VPCS is a Cray YMP. The CFS is implemented on an RS 6000 using the UniTree Mass Storage System. To better meet the science and engineering computing requirements, EADS II must be monitored, its performance analyzed, and appropriate modifications for performance improvement made. Implementing this approach requires tool(s) to assist in performance monitoring and analysis. In Spring 1994, PerfStat 2.0 was purchased to meet these needs for the VPCS and the CFS. PerfStat(2) is a set of tools that can be used to analyze both historical and real-time performance data. Its flexible design allows significant user customization. The user identifies what data is collected, how it is classified, and how it is displayed for evaluation. Both graphical and tabular displays are supported. The capability of the PerfStat tool was evaluated, appropriate modifications to EADS II to optimize throughput and enhance productivity were suggested and implemented, and the effects of these modifications on the systems performance were observed. In this paper, the PerfStat tool is described, then its use with EADS II is outlined briefly. Next, the evaluation of the VPCS, as well as the modifications made to the system are described. Finally, conclusions are drawn and recommendations for future worked are outlined.

  4. Perturbing engine performance measurements to determine optimal engine control settings

    DOEpatents

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2014-12-30

    Methods and systems for optimizing a performance of a vehicle engine are provided. The method includes determining an initial value for a first engine control parameter based on one or more detected operating conditions of the vehicle engine, determining a value of an engine performance variable, and artificially perturbing the determined value of the engine performance variable. The initial value for the first engine control parameter is then adjusted based on the perturbed engine performance variable causing the engine performance variable to approach a target engine performance variable. Operation of the vehicle engine is controlled based on the adjusted initial value for the first engine control parameter. These acts are repeated until the engine performance variable approaches the target engine performance variable.

  5. Energy Efficient Engine (E3) combustion system component technology performance report

    NASA Technical Reports Server (NTRS)

    Burrus, D. L.; Chahrour, C. A.; Foltz, H. L.; Sabla, P. E.; Seto, S. P.; Taylor, J. R.

    1984-01-01

    The Energy Efficient Engine (E3) combustor effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent of this effort was to evolve a design that meets the stringent emissions and life goals of the E3, as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this effort was incorporated into the engine combustion hardware design. The advanced engine combustion system was then evaluated in component testing to verify the design intent. What evolved from this effort was an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3.

  6. Optimal analysis of the performance of an irreversible quantum heat engine with spin systems

    NASA Astrophysics Data System (ADS)

    Lin, Bihong; Chen, Jincan

    2005-01-01

    It is considered that the cycle of a quantum heat engine using many non-interacting spin-1/2 systems as the working substance is composed of two adiabatic and two isomagnetic field processes and is referred to as a spin quantum Brayton engine cycle. Based on the quantum master equation and semi-group approach, expressions for the efficiency and power output of the cycle are derived. By using numerical solutions, the power output of the heat engine subject to finite cycle duration is optimized. The maximum power output and the corresponding parameters are calculated numerically. The optimal region of the efficiency and the optimal ranges of temperatures of the working substance and times spent on the two isomagnetic field processes are determined, so that the general optimum performance characteristics of the cycle are revealed. Moreover, the optimal performance of the cycle in the high-temperature limit is also analysed in detail. The results obtained here are further generalized, so that they may be directly used to describe the performance of a quantum Brayton heat engine using spin-J systems as the working substance.

  7. Performance of Stirling Engines

    NASA Astrophysics Data System (ADS)

    Iwamoto, Shoichi; Hirata, Koichi; Toda, Fujio

    We have developed five kinds of high- and low-temperature differential Stirling engines and their engine performance was investigated experimentally. In order to determine the parameters that affect engine performance, experimental results were discussed and compared with results calculated using analytical methods. We show an arranging method for the experimental results, and consider the performance of general Stirling engines. After using the arranging method with nondimensional numbers obtained by a dimensional analysis, a prediction method, which is used at the early design stage, is formulated. One of the nondimensional numbers in this prediction method is calculated based on engine specifications, including the properties of the working gas. The prediction method can predict engine speed, output power, the effect of working gas and operating conditions.

  8. Performance of a 10kW underwater diesel engine system

    SciTech Connect

    Potter, I.J.; Reader, G.T.; Bowen, C.E.

    1997-12-31

    To operate in a non-air environment a diesel engine must be supplied with a synthetic atmosphere which mimics the role of normally aspirated air. Usually, this synthetic atmosphere is made up of a pure oxygen supply and recirculated exhaust gases. Not all of the exhaust gases will be recycled as the system would become over-pressurized and therefore a portion of the gases are expelled from the system. Moreover, to control the amount of carbon dioxide in the recycled gas a scrubbing device may be used. Thus, the intake oxidant mixture will consist of a varying proportions of oxygen, carbon dioxide and a diluent such as nitrogen. Whatever, the exact composition of the mixture the general objective is to produce a mixture which enables the engine to attain at least the same performance as when running with a normal air mixture over the full load and speed range. To determine the optimum synthetic atmosphere mixture an intensive experimental investigation has been carried out by the authors using a specially developed test rig. Provision has been made on the test rig so that a number of different composition synthetic atmospheres can be produced. In this way it has been possible to measure the effects of carbon dioxide ratios on the performance of the diesel engine. In addition to the shaft performance, power and fuel efficiency, exhaust gas emissions and combustion noise have also been measured. This paper details the operational principle of an underwater diesel engine and reports on the performance of such an engine while operating with high intake carbon dioxide levels.

  9. System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Matijevic, J. R.

    1987-01-01

    Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

  10. Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.

    1979-01-01

    The computational techniques utilized to determine the optimum propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements are described. The characteristics and use of the following computer codes are discussed: (1) NNEP - a very general cycle analysis code that can assemble an arbitrary matrix fans, turbines, ducts, shafts, etc., into a complete gas turbine engine and compute on- and off-design thermodynamic performance; (2) WATE - a preliminary design procedure for calculating engine weight using the component characteristics determined by NNEP; (3) POD DRG - a table look-up program to calculate wave and friction drag of nacelles; (4) LIFCYC - a computer code developed to calculate life cycle costs of engines based on the output from WATE; and (5) INSTAL - a computer code developed to calculate installation effects, inlet performance and inlet weight. Examples are given to illustrate how these computer techniques can be applied to analyze and optimize propulsion system fuel consumption, weight, and cost for representative types of aircraft and missions.

  11. A high performance thermoacoustic engine

    NASA Astrophysics Data System (ADS)

    Tijani, M. E. H.; Spoelstra, S.

    2011-11-01

    In thermoacoustic systems heat is converted into acoustic energy and vice versa. These systems use inert gases as working medium and have no moving parts which makes the thermoacoustic technology a serious alternative to produce mechanical or electrical power, cooling power, and heating in a sustainable and environmentally friendly way. A thermoacoustic Stirling heat engine is designed and built which achieves a record performance of 49% of the Carnot efficiency. The design and performance of the engine is presented. The engine has no moving parts and is made up of few simple components.

  12. Performance Assessment of a Desiccant Cooling System in a CHP Application with an IC Engine

    SciTech Connect

    Jalalzadeh-Azar, A. A.; Slayzak, S.; Judkoff, R.; Schaffhauser, T.; DeBlasio, R.

    2005-04-01

    Performance of a desiccant cooling system was evaluated in the context of combined heat and power (CHP). The baseline system incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The desiccant unit was regenerated through heat recovery from a gas-fired reciprocating internal combustion engine. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic conditions, while allowing influx of outside air in excess of what is typically required for commercial buildings. Energy and water efficiencies of the desiccant cooling system were also evaluated and compared with those of a conventional system. The results of parametric assessments revealed the importance of using a heat exchanger for concurrent desiccant post cooling and regeneration air preheating. These functions resulted in enhancement of both the cooling performance and the thermal efficiency, which are essential for fuel utilization improvement. Two approaches for mixing of the return air and outside air were examined, and their impact on the system cooling performance and thermal efficiency was demonstrated. The scope of the parametric analyses also encompassed the impact of improving the indirect evaporative cooling effectiveness on the overall cooling system performance.

  13. Mod II engine performance

    NASA Technical Reports Server (NTRS)

    Richey, Albert E.; Huang, Shyan-Cherng

    1987-01-01

    The testing of a prototype of an automotive Stirling engine, the Mod II, is discussed. The Mod II is a one-piece cast block with a V-4 single-crankshaft configuration and an annular regenerator/cooler design. The initial testing of Mod II concentrated on the basic engine, with auxiliaries driven by power sources external to the engine. The performance of the engine was tested at 720 C set temperature and 820 C tube temperature. At 720 C, it is observed that the power deficiency is speed dependent and linear, with a weak pressure dependency, and at 820 C, the power deficiency is speed and pressure dependent. The effects of buoyancy and nozzle spray pattern on the heater temperature spread are investigated. The characterization of the oil pump and the operating cycle and temperature spread tests are proposed for further evaluation of the engine.

  14. Study on Operating Performance of Stirling Engine-Driven Vapor Compression Heat Pump System

    NASA Astrophysics Data System (ADS)

    Kagawa, Noboru

    Stirling engines have many unique advantages including higher thermal efficiencies, preferable exhaust gas characteristics, multi-fuel usage, and low noise and vibration. On the other hand, heat pump systems are very attractive for space heating and cooling, and industrial usage. There are several environmental merits of Stirling driven vapor compression (SDVC) systems. A design method for the SDVC, which is based on mathematical methods for Stirling and Ranking cycles, has been developed. The attractive SDVC performance using conventional and alternative refrigerants was shown. From the calculated Total Equivalent Warming Impact (TEWI) and operating costs, it became clear that the SDVC system with the alternative refrigerant has a higher potential as the future air-conditioning system.

  15. Engineering Spectral Control Using Front Surface Filters for Maximum TPV Energy Conversion System Performance

    SciTech Connect

    T Rahmlow, Jr; J Lazo-Wasem, E Gratrix; J Azarkevich; E Brown; D DePoy; D Eno; P Fourspring; J Parrington; R Mahorter; B Wernsman

    2004-10-14

    Energy conversion efficiencies of better than 23% have been demonstrated for small scale tests of a few thermophotovoltaic (TPV) cells using front surface, tandem filters [1, 2]. The engineering challenge is to build this level of efficiency into arrays of cells that provide useful levels of energy. Variations in cell and filter performance will degrade TPV array performance. Repeated fabrication runs of several filters each provide an initial quantification of the fabrication variation for front surface, tandem filters for TPV spectral control. For three performance statistics, within-run variation was measured to be 0.7-1.4 percent, and run-to-run variation was measured to be 0.5-3.2 percent. Fabrication runs using a mask have been shown to reduce variation across interference filters from as high as 8-10 percent to less than 1.5 percent. Finally, several system design and assembly approaches are described to further reduce variation.

  16. L-Band Digital Aeronautical Communications System Engineering - Concepts of Use, Systems Performance, Requirements, and Architectures

    NASA Technical Reports Server (NTRS)

    Zelkin, Natalie; Henriksen, Stephen

    2010-01-01

    This NASA Contractor Report summarizes and documents the work performed to develop concepts of use (ConUse) and high-level system requirements and architecture for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. This work was completed as a follow-on to the technology assessment conducted by NASA Glenn Research Center and ITT for the Future Communications Study (FCS). ITT assessed air-to-ground (A/G) communications concepts of use and operations presented in relevant NAS-level, international, and NAS-system-level documents to derive the appropriate ConUse relevant to potential A/G communications applications and services for domestic continental airspace. ITT also leveraged prior concepts of use developed during the earlier phases of the FCS. A middle-out functional architecture was adopted by merging the functional system requirements identified in the bottom-up assessment of existing requirements with those derived as a result of the top-down analysis of ConUse and higher level functional requirements. Initial end-to-end system performance requirements were derived to define system capabilities based on the functional requirements and on NAS-SR-1000 and the Operational Performance Assessment conducted as part of the COCR. A high-level notional architecture of the L-DACS supporting A/G communication was derived from the functional architecture and requirements.

  17. Nuclear propulsion systems engineering

    SciTech Connect

    Madsen, W.W.; Neuman, J.E.: Van Haaften, D.H.

    1992-12-31

    The Nuclear Energy for Rocket Vehicle Application (NERVA) program of the 1960`s and early 1970`s was dramatically successful, with no major failures during the entire testing program. This success was due in large part to the successful development of a systems engineering process. Systems engineering, properly implemented, involves all aspects of the system design and operation, and leads to optimization of theentire system: cost, schedule, performance, safety, reliability, function, requirements, etc. The process must be incorporated from the very first and continued to project completion. This paper will discuss major aspects of the NERVA systems engineering effort, and consider the implications for current nuclear propulsion efforts.

  18. Nuclear propulsion systems engineering

    SciTech Connect

    Madsen, W.W.; Neuman, J.E.: Van Haaften, D.H.

    1992-01-01

    The Nuclear Energy for Rocket Vehicle Application (NERVA) program of the 1960's and early 1970's was dramatically successful, with no major failures during the entire testing program. This success was due in large part to the successful development of a systems engineering process. Systems engineering, properly implemented, involves all aspects of the system design and operation, and leads to optimization of theentire system: cost, schedule, performance, safety, reliability, function, requirements, etc. The process must be incorporated from the very first and continued to project completion. This paper will discuss major aspects of the NERVA systems engineering effort, and consider the implications for current nuclear propulsion efforts.

  19. PEM fuel cell stack performance using dilute hydrogen mixture. Implications on electrochemical engine system performance and design

    SciTech Connect

    Inbody, M.A.; Vanderborgh, N.E.; Hedstrom, J.C.; Tafoya, J.I.

    1996-12-31

    Onboard fuel processing to generate a hydrogen-rich fuel for PEM fuel cells is being considered as an alternative to stored hydrogen fuel for transportation applications. If successful, this approach, contrasted to operating with onboard hydrogen, utilizes the existing fuels infrastructure and provides required vehicle range. One attractive, commercial liquid fuels option is steam reforming of methanol. However, expanding the liquid methanol infrastructure will take both time and capital. Consequently technology is also being developed to utilize existing transportation fuels, such as gasoline or diesel, to power PEM fuel cell systems. Steam reforming of methanol generates a mixture with a dry gas composition of 75% hydrogen and 25% carbon dioxide. Steam reforming, autothermal reforming, and partial oxidation reforming of C{sub 2} and larger hydrocarbons produces a mixture with a more dilute hydrogen concentration (65%-40%) along with carbon dioxide ({approx}20%) and nitrogen ({approx}10%-40%). Performance of PEM fuel cell stacks on these dilute hydrogen mixtures will affect the overall electrochemical engine system design as well as the overall efficiency. The Los Alamos Fuel Cell Stack Test facility was used to access the performance of a PEM Fuel cell stack over the range of gas compositions chosen to replicate anode feeds from various fuel processing options for hydrocarbon and alcohol fuels. The focus of the experiments was on the anode performance with dilute hydrogen mixtures with carbon dioxide and nitrogen diluents. Performance with other anode feed contaminants, such as carbon monoxide, are not reported here.

  20. Strutjet RBCC Engine Performance

    NASA Technical Reports Server (NTRS)

    Bulman, Mel; Neill, Todd; Yam, Clement

    1999-01-01

    In the past two years Strutjet Rocket Based Combined Cycle (RBCC) engine has been tested extensively under the Advanced Reusable Technology (ART) contract from NASA MSFC. RBCC Engines combine the high thrust to weight of the rocket with the high efficiency of the ramjet engine. This propulsion system has the potential to reduce the cost of launching payloads to orbit by up to a factor of 100. In the ART program we have conducted over 100 hot fire tests. The propellants have been hydrogen and oxygen. The Modes tested have included the Air Augmented Rocket (AAR) from M = 0 to 2.4, the Ramjet at M = 2.4 & 6, Scramjet at M = 6 & 8, Scram/Rocket at Mach 8 and Ascent Rocket in Vacuum. This invited paper will present an overview of these test results and plans for future development of this propulsion cycle.

  1. What is systems engineering?

    SciTech Connect

    Bahill, A.T.

    1995-08-01

    Systems Engineering is an interdisciplinary process that ensures that the customers` needs are satisfied throughout a system`s entire life cycle. This process includes: understanding customer needs; stating the problem; specifying requirements; defining performance and cost measures, prescribing tests, validating requirements, conducting design reviews, exploring alternative concepts, sensitivity analyses, functional decomposition, system design, designing and managing interfaces, system integration, total system test, configuration management, risk management, reliability analysis; total quality management; project management; and documentation. Material for this paper was gathered from senior Systems Engineers at Sandia National Laboratories.

  2. Engineering development of coal-fired high-performance power systems. Technical report, July - September 1996

    SciTech Connect

    1996-11-01

    A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, AlliedSignal Aerospace Equipment Systems, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase I of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalent size PC plant. The concept uses a pyrolyzation process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). It is a pulverized fuel-fired boiler/airheater where steam and gas turbine air are indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and then a pilot plant with integrated pyrolyzer and char combustion systems will be tested. In this report, progress in the pyrolyzer pilot plant preparation is reported. The results of extensive laboratory and bench scale testing of representative char are also reported. Preliminary results of combustion modeling of the char combustion system are included. There are also discussions of the auxiliary systems that are planned for the char combustion system pilot plant and the status of the integrated system pilot plant.

  3. Selection of a computer code for Hanford low-level waste engineered-system performance assessment

    SciTech Connect

    McGrail, B.P.; Mahoney, L.A.

    1995-10-01

    Planned performance assessments for the proposed disposal of low-level waste (LLW) glass produced from remediation of wastes stored in underground tanks at Hanford, Washington will require calculations of radionuclide release rates from the subsurface disposal facility. These calculations will be done with the aid of computer codes. Currently available computer codes were ranked in terms of the feature sets implemented in the code that match a set of physical, chemical, numerical, and functional capabilities needed to assess release rates from the engineered system. The needed capabilities were identified from an analysis of the important physical and chemical process expected to affect LLW glass corrosion and the mobility of radionuclides. The highest ranked computer code was found to be the ARES-CT code developed at PNL for the US Department of Energy for evaluation of and land disposal sites.

  4. Performance modeling & simulation of complex systems (A systems engineering design & analysis approach)

    NASA Technical Reports Server (NTRS)

    Hall, Laverne

    1995-01-01

    Modeling of the Multi-mission Image Processing System (MIPS) will be described as an example of the use of a modeling tool to design a distributed system that supports multiple application scenarios. This paper examines: (a) modeling tool selection, capabilities, and operation (namely NETWORK 2.5 by CACl), (b) pointers for building or constructing a model and how the MIPS model was developed, (c) the importance of benchmarking or testing the performance of equipment/subsystems being considered for incorporation the design/architecture, (d) the essential step of model validation and/or calibration using the benchmark results, (e) sample simulation results from the MIPS model, and (f) how modeling and simulation analysis affected the MIPS design process by having a supportive and informative impact.

  5. The innate immune system contributes to tissue-engineered vascular graft performance

    PubMed Central

    Hibino, Narutoshi; Mejias, Dane; Pietris, Nicholas; Dean, Ethan; Yi, Tai; Best, Cameron; Shinoka, Toshiharu; Breuer, Christopher

    2015-01-01

    The first clinical trial of tissue-engineered vascular grafts (TEVGs) identified stenosis as the primary cause of graft failure. In this study, we aimed to elucidate the role of the host immune response in the development of stenosis using a murine model of TEVG implantation. We found that the C.B-17 wild-type (WT) mouse (control) undergoes a dramatic stenotic response, which is nearly completely abolished in the immunodeficient SCID/beige (bg) variant. SCID mice, which lack an adaptive immune system due to the absence of T and B lymphocytes, experienced rates of stenosis comparable to WT controls (average luminal diameter, WT: 0.071 ± 0.035 mm, SCID: 0.137 ± 0.032 mm, SCID/bg: 0.804 ± 0.039 mm; P < 0.001). The bg mutation is characterized by NK cell and platelet dysfunction, and systemic treatment of WT mice with either NK cell–neutralizing (anti–NK 1.1 antibody) or antiplatelet (aspirin/Plavix [clopidogrel bisulfate]; Asp/Pla) therapy achieved nearly half the patency observed in the SCID/bg mouse (NK Ab: 0.356 ± 0.151 mm, Asp/Pla: 0.452 ± 0.130 mm). Scaffold implantation elicited a blunted immune response in SCID/bg mice, as demonstrated by macrophage number and mRNA expression of proinflammatory cytokines in TEVG explants. Implicating the initial innate immune response as a critical factor in graft stenosis may provide a strategy for prognosis and therapy of second-generation TEVGs.—Hibino, N., Mejias, D., Pietris, N., Dean, E., Yi, T., Best, C., Shinoka, T., Breuer, C. The innate immune system contributes to tissue-engineered vascular graft performance. PMID:25713026

  6. ENGINEERING DEVELOPMENT OF COAL-FIRED HIGH-PERFORMANCE POWER SYSTEMS

    SciTech Connect

    1998-11-01

    A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase 1 of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalent size PC plant. The concept uses a pyrolyzation process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). The HITAF is a pulverized fuel-fired boiler/air heater where steam is generated and gas turbine air is indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2, which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and after each experimental program has been completed, a larger scale pyrolyzer will be tested at the Power Systems Development Facility (PSDF) in Wilsonville, Al. The facility is equipped with a gas turbine and a topping combustor, and as such, will provide an opportunity to evaluate integrated pyrolyzer and turbine operation. The design of the char burner was completed during this quarter. The burner is designed for arch-firing and has a maximum capacity of 30 MMBtu/hr. This size represents a half scale version of a typical commercial burner. The burner is outfitted with

  7. The Effect of Rotor Cruise Tip Speed, Engine Technology and Engine/Drive System RPM on the NASA Large Civil Tiltrotor (LCTR2) Size and Performance

    NASA Technical Reports Server (NTRS)

    Robuck, Mark; Wilkerson, Joseph; Maciolek, Robert; Vonderwell, Dan

    2012-01-01

    A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.

  8. Engineering development of coal-fired high performance power systems, Phase II and III

    SciTech Connect

    1999-04-01

    The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: thermal efficiency (HHV) {ge} 47%, NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) coal providing {ge} 65% of heat input, all solid wastes benign, and cost of electricity {le} 90% of present plants. Phase 1, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase 1 also included preliminary R and D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. This phase, Phase 2, involves the development and testing of plant subsystems, refinement and updating of the HIPPS commercial plant design, and the site selection and engineering design of a HIPPS prototype plant. Work reported herein is from: Task 2.1 HITAC Combustors; Task 2.2 HITAF Air Heaters; Task 6 HIPPS Commercial Plant Design Update.

  9. Engineering development of coal-fired high performance power systems phase 2 and 3

    SciTech Connect

    Unknown

    1999-08-01

    The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: thermal efficiency (HHV) {ge} 47%; NOx, SOx, and particulates {le}10% NSPS (New Source Performance Standard); coal providing {ge} 65% of heat input; all solid wastes benign; and cost of electricity {le} 90% of present plants. Phase 1, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase 1 also included preliminary R and D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. This phase, Phase 2, involves the development and testing of plant subsystems, refinement and updating of the HIPPS commercial plant design, and the site selection and engineering design of a HIPPS prototype plant. Work reported herein is from: Task 2.2 HITAF Air Heaters; and Task 2.4 Duct Heater and Gas Turbine Integration.

  10. Engineering development of coal-fired high performance power systems, Phase II and III

    SciTech Connect

    1999-01-01

    The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: thermal efficiency (HHV) {ge} 47%; NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) coal providing {ge} 65% of heat input; all solid wastes benign; cost of electricity {le} 90% of present plants. Phase 1, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase 1 also included preliminary R and D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. This phase, Phase 2, involves the development and testing of plant subsystems, refinement and updating of the HIPPS commercial plant design, and the site selection and engineering design of a HIPPS prototype plant. Work reported herein is from: Task 2.1 HITAC Combustors; Task 2.2 HITAF Air Heaters; Task 6 HIPPS Commercial Plant Design Update.

  11. Rocket engine condition monitoring system

    SciTech Connect

    Hagar, S.K.; Alcock, J.F.

    1989-01-01

    It is expected that the Rocket Engine Condition Monitoring System (RECMS) program will define engine monitoring technologies and an integration approach which can be applied to engine development in support of advanced launch system objectives. The RECMS program approaches engine monitoring as a system which is fully integrated with the engine controller, vehicle monitoring system, and ground processing systems to ensure mission success in addition to engine reliability. The system components are monitored through health and performance sensors; they are analyzed with the diagnostic and prognostic algorithms and demonstrated by system testing with hardware from other advanced development programs.

  12. Engineering development of coal-fired high-performance power systems

    SciTech Connect

    1999-10-01

    A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase 1 of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalent size PC plant. The concept uses a pyrolysis process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). The HITAF is a pulverized fuel-fired boiler/air heater where steam is generated and gas turbine air is indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and after each experimental program has been completed, a larger scale pyrolyzer will be tested at the Power Systems Development Facility (PSDF) in Wilsonville, AL. The facility is equipped with a gas turbine and a topping combustor, and as such, will provide an opportunity to evaluate integrated pyrolyzer and turbine operation. This report addresses the areas of technical progress for this quarter. Analysis of the arch-fired burner continued during this quarter. Unburned carbon and NOx performance are included in this report. Construction commenced this quarter to modify the CETF

  13. Engineering Development of Coal-Fired High-Performance Power Systems

    SciTech Connect

    York Tsuo

    2000-12-31

    A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase 1 of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalent size PC plant. The concept uses a pyrolysis process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). The HITAF is a pulverized fuel-fired boiler/air heater where steam is generated and gas turbine air is indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately. This report addresses the areas of technical progress for this quarter. The detail of syngas cooler design is given in this report. The final construction work of the CFB pyrolyzer pilot plant has started during this quarter. No experimental testing was performed during this quarter. The proposed test matrix for the future CFB pyrolyzer tests is given in this report. Besides testing various fuels, bed temperature will be the primary test parameter.

  14. Engine Performance (Section B: Fuel and Exhaust Systems). Auto Mechanics Curriculum Guide. Module 3. Instructor's Guide.

    ERIC Educational Resources Information Center

    Rains, Larry

    This module is the third of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Six units cover: fuel supply systems; carburetion; carburetor service; gasoline engine electronic fuel injection; diesel fuel injection; and exhaust systems and turbochargers. Introductory materials include a competency profile and…

  15. Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development & Performance Analysis

    NASA Technical Reports Server (NTRS)

    Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan

    2014-01-01

    ATA-002 Technical Team has successfully designed, developed, tested and assessed the SLS Pathfinder propulsion systems for the Main Base Heating Test Program. Major Outcomes of the Pathfinder Test Program: Reach 90% of full-scale chamber pressure Achieved all engine/motor design parameter requirements Reach steady plume flow behavior in less than 35 msec Steady chamber pressure for 60 to 100 msec during engine/motor operation Similar model engine/motor performance to full-scale SLS system Mitigated nozzle throat and combustor thermal erosion Test data shows good agreement with numerical prediction codes Next phase of the ATA-002 Test Program Design & development of the SLS OML for the Main Base Heating Test Tweak BSRM design to optimize performance Tweak CS-REM design to increase robustness MSFC Aerosciences and CUBRC have the capability to develop sub-scale propulsion systems to meet desired performance requirements for short-duration testing.

  16. Engineering development of coal-fired high-performance power systems

    SciTech Connect

    1999-05-01

    A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase 1 of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalent size PC plant. The concept uses a pyrolysis process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). The HITAF is a pulverized fuel-fired boiler/air heater where steam is generated and gas turbine air is indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and after each experimental program has been completed, a larger scale pyrolyzer will be tested at the Power Systems Development Facility (PSDF) in Wilsonville, AL. The facility is equipped with a gas turbine and a topping combustor, and as such, will provide an opportunity to evaluate integrated pyrolyzer and turbine operation. This report addresses the areas of technical progress for this quarter. The char combustion tests in the arch-fired arrangement were completed this quarter. A total of twenty-one setpoints were successfully completed, firing both synthetically-made char

  17. Engineering Review Information System

    NASA Technical Reports Server (NTRS)

    Grems, III, Edward G. (Inventor); Henze, James E. (Inventor); Bixby, Jonathan A. (Inventor); Roberts, Mark (Inventor); Mann, Thomas (Inventor)

    2015-01-01

    A disciplinal engineering review computer information system and method by defining a database of disciplinal engineering review process entities for an enterprise engineering program, opening a computer supported engineering item based upon the defined disciplinal engineering review process entities, managing a review of the opened engineering item according to the defined disciplinal engineering review process entities, and closing the opened engineering item according to the opened engineering item review.

  18. Performance of a shaft seal system for the LE-7 rocket engine oxidizer turbopump

    NASA Astrophysics Data System (ADS)

    Oike, Mamoru; Nosaka, Masataka; Kikuchi, Masataka; Watanabe, Yoshiaki

    An experimental study on a rotating-shaft seal system for a high-pressure liquid oxygen (LOX) turbopump has been conducted to develop the LE-7 engine for the Japanese H-II launch vehicle. The LOX turbopump rotating-shaft seal system, which prevents LOX (4.9 MPa) and the high-pressure turbine-drive gas (16.6 MPa, 970 K) from mixing during high-speed operations (18,000 to 20,000 rpm), consists of the following seals: an LOX seal comprising a floating-ring and a wear-ring, a turbine gas seal comprising two floating-rings, and a helium purge seal comprising two segmented circumferential seal-rings. This report describes experimental and observational results concerning the rotating-shaft seal system obtained in the LOX turbopump operations and the seal tests. Based on comparisons between the measurements and the analytical results, sealing characteristics of the seal system are discussed. Inspections of the sealing surfaces after the engine firing tests demonstrated that the LOX turbopump rotating-shaft seal system has sufficient durability for use in the LE-7 engine for the H-II launch vehicle.

  19. Space engine safety system

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Meyer, Claudia M.

    1991-01-01

    A rocket engine safety system is designed to initiate control procedures which will minimize damage to the engine and vehicle or test stand in the event of an engine failure. This report describes the features and the implementation issues associated with rocket engine safety systems. Specific concerns of safety systems applied to a space-based engine and long duration space missions are discussed. Examples of safety system features and architectures are given from recent safety monitoring investigations conducted for the Space Shuttle Main Engine and for future liquid rocket engines. Also, a general design and implementation process for rocket engine safety systems is presented.

  20. Space engine safety system

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Meyer, Claudia M.

    1991-01-01

    A rocket engine safety system was designed to initiate control procedures to minimize damage to the engine or vehicle or test stand in the event of an engine failure. The features and the implementation issues associated with rocket engine safety systems are discussed, as well as the specific concerns of safety systems applied to a space-based engine and long duration space missions. Examples of safety system features and architectures are given, based on recent safety monitoring investigations conducted for the Space Shuttle Main Engine and for future liquid rocket engines. Also, the general design and implementation process for rocket engine safety systems is presented.

  1. Engineering scalable biological systems

    PubMed Central

    2010-01-01

    Synthetic biology is focused on engineering biological organisms to study natural systems and to provide new solutions for pressing medical, industrial and environmental problems. At the core of engineered organisms are synthetic biological circuits that execute the tasks of sensing inputs, processing logic and performing output functions. In the last decade, significant progress has been made in developing basic designs for a wide range of biological circuits in bacteria, yeast and mammalian systems. However, significant challenges in the construction, probing, modulation and debugging of synthetic biological systems must be addressed in order to achieve scalable higher-complexity biological circuits. Furthermore, concomitant efforts to evaluate the safety and biocontainment of engineered organisms and address public and regulatory concerns will be necessary to ensure that technological advances are translated into real-world solutions. PMID:21468204

  2. Modeling the Effects of Ice Accretion on the Low Pressure Compressor and the Overall Turbofan Engine System Performance

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.; Jorgenson, Philip C. E.; Wright, William B.

    2011-01-01

    The focus of this study is on utilizing a mean line compressor flow analysis code coupled to an engine system thermodynamic code, to estimate the effects of ice accretion on the low pressure compressor, and quantifying its effects on the engine system throughout a notional flight trajectory. In this paper a temperature range in which engine icing would occur was assumed. This provided a mechanism to locate potential component icing sites and allow the computational tools to add blockages due to ice accretion in a parametric fashion. Ultimately the location and level of blockage due to icing would be provided by an ice accretion code. To proceed, an engine system modeling code and a mean line compressor flow analysis code were utilized to calculate the flow conditions in the fan-core and low pressure compressor and to identify potential locations within the compressor where ice may accrete. In this study, an "additional blockage" due to the accretion of ice on the metal surfaces, has been added to the baseline aerodynamic blockage due to boundary layer, as well as the blade metal blockage. Once the potential locations of ice accretion are identified, the levels of additional blockage due to accretion were parametrically varied to estimate the effects on the low pressure compressor blade row performance operating within the engine system environment. This study includes detailed analysis of compressor and engine performance during cruise and descent operating conditions at several altitudes within the notional flight trajectory. The purpose of this effort is to develop the computer codes to provide a predictive capability to forecast the onset of engine icing events, such that they could ultimately help in the avoidance of these events.

  3. A 727/JT8D-100 series engine exhaust system propulsion performance model test

    NASA Technical Reports Server (NTRS)

    Haugan, W. J.; Kern, P. R. A.

    1974-01-01

    The results are presented from testing one-eighth scale models of the Pratt and Whitney aircraft reference and Boeing nozzles for the JT8D-100 series mixed flow engines. The objective of the test was to obtain the nozzle velocity and flow coefficients for the reference configurations and compare these with the Boeing configurations which incorporated a longer splitter between the fan and primary flows. A further comparison was made between the JT8D-100 series nozzles and the Boeing JT8D-9/727 production nozzle performance. A statistical analysis was used to compare configurations which showed the performance (velocity coefficient) of the reference and the Boeing configuration was the same for the JT8D-109. It also showed no difference between reference and the Boeing configuration for the JT8D-115 and no difference for the JT8D-117 nozzles. Bypass ratio (match) was shown to be equally dependent on splitter position as on nozzle area within the range investigated. The nozzles were very similar in flow coefficient within an engine family. Excellent profile data was recorded. The effects of swirl on the nozzle performance was examined and found to degrade the velocity and flow coefficients.

  4. Sensitivity Analysis of Wind Plant Performance to Key Turbine Design Parameters: A Systems Engineering Approach; Preprint

    SciTech Connect

    Dykes, K.; Ning, A.; King, R.; Graf, P.; Scott, G.; Veers, P.

    2014-02-01

    This paper introduces the development of a new software framework for research, design, and development of wind energy systems which is meant to 1) represent a full wind plant including all physical and nonphysical assets and associated costs up to the point of grid interconnection, 2) allow use of interchangeable models of varying fidelity for different aspects of the system, and 3) support system level multidisciplinary analyses and optimizations. This paper describes the design of the overall software capability and applies it to a global sensitivity analysis of wind turbine and plant performance and cost. The analysis was performed using three different model configurations involving different levels of fidelity, which illustrate how increasing fidelity can preserve important system interactions that build up to overall system performance and cost. Analyses were performed for a reference wind plant based on the National Renewable Energy Laboratory's 5-MW reference turbine at a mid-Atlantic offshore location within the United States.

  5. PERC 2 High-End Computer System Performance: Scalable Science and Engineering

    SciTech Connect

    Daniel Reed

    2006-10-15

    During two years of SciDAC PERC-2, our activities had centered largely on development of new performance analysis techniques to enable efficient use on systems containing thousands or tens of thousands of processors. In addition, we continued our application engagement efforts and utilized our tools to study the performance of various SciDAC applications on a variety of HPC platforms.

  6. ATS-6 engineering performance report. Volume:Program and systems summaries: Mechanical and thermal details

    NASA Technical Reports Server (NTRS)

    Wales, R. O. (Editor)

    1981-01-01

    The overall mission and spacecraft systems, testing, and operations are summarized. The mechanical subsystems are reviewed, encompassing mechanical design requirements; separation and deployment mechanisms; design and performance evaluation; and the television camera reflector monitor. Thermal control and contamination are discussed in terms of thermal control subsystems, design validation, subsystems performance, the advanced flight experiment, and the quartz-crystal microbalance contamination monitor.

  7. Program (systems) engineering

    NASA Technical Reports Server (NTRS)

    Baroff, Lynn E.; Easter, Robert W.; Pomphrey, Richard B.

    2004-01-01

    Program Systems Engineering applies the principles of Systems Engineering at the program level. Space programs are composed of interrelated elements which can include collections of projects, advanced technologies, information systems, etc. Some program elements are outside traditional engineering's physical systems, such as education and public outreach, public relations, resource flow, and interactions within the political environments.

  8. Preparing systems engineering and computing science students in disciplined methods, quantitative, and advanced statistical techniques to improve process performance

    NASA Astrophysics Data System (ADS)

    McCray, Wilmon Wil L., Jr.

    The research was prompted by a need to conduct a study that assesses process improvement, quality management and analytical techniques taught to students in U.S. colleges and universities undergraduate and graduate systems engineering and the computing science discipline (e.g., software engineering, computer science, and information technology) degree programs during their academic training that can be applied to quantitatively manage processes for performance. Everyone involved in executing repeatable processes in the software and systems development lifecycle processes needs to become familiar with the concepts of quantitative management, statistical thinking, process improvement methods and how they relate to process-performance. Organizations are starting to embrace the de facto Software Engineering Institute (SEI) Capability Maturity Model Integration (CMMI RTM) Models as process improvement frameworks to improve business processes performance. High maturity process areas in the CMMI model imply the use of analytical, statistical, quantitative management techniques, and process performance modeling to identify and eliminate sources of variation, continually improve process-performance; reduce cost and predict future outcomes. The research study identifies and provides a detail discussion of the gap analysis findings of process improvement and quantitative analysis techniques taught in U.S. universities systems engineering and computing science degree programs, gaps that exist in the literature, and a comparison analysis which identifies the gaps that exist between the SEI's "healthy ingredients " of a process performance model and courses taught in U.S. universities degree program. The research also heightens awareness that academicians have conducted little research on applicable statistics and quantitative techniques that can be used to demonstrate high maturity as implied in the CMMI models. The research also includes a Monte Carlo simulation optimization

  9. Engineering performance monitoring: Sustained contributions to plant performance improvement

    SciTech Connect

    Bebko, J.J. )

    1992-01-01

    With the aim of achieving excellence in an engineering department that makes both individual project-by-project contributions to plant performance improvement and sustained overall contributions to plant performance, the Niagara Mohawk Nuclear Engineering Department went back to the basics of running a business and established an Engineering Performance Monitoring System. This system focused on the unique products and services of the department and their cost, schedule, and quality parameters. The goals were to provide the best possible service to customers and the generation department and to be one of the best engineering departments in the industry.

  10. Improved Stirling engine performance using jet impingement

    NASA Technical Reports Server (NTRS)

    Johnson, D. C.; Britt, E. J.; Thieme, L. G.

    1982-01-01

    Of the many factors influencing the performance of a Stirling engine, that of transferring the combustion gas heat into the working fluid is crucial. By utilizing the high heat transfer rates obtainable with a jet impingement heat transfer system, it is possible to reduce the flame temperature required for engine operation. Also, the required amount of heater tube surface area may be reduced, resulting in a decrease in the engine nonswept volume and a related increase in engine efficiency. A jet impingement heat transfer system was designed by Rasor Associates, Inc., and tested in the GPU-3 Stirling engine at the NASA Lewis Research Center. For a small penalty in pumping power (less than 0.5% of engine output) the jet impingement heat transfer system provided a higher combustion-gas-side heat transfer coefficient and a smoothing of heater temperature profiles resulting in lower combustion system temperatures and a 5 to 8% increase in engine power output and efficiency.

  11. NASA Systems Engineering Handbook

    NASA Technical Reports Server (NTRS)

    Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; Mcduffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

    1995-01-01

    This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive. Superseded by: NASA/SP-2007-6105 Rev 1 (20080008301).

  12. SHARP's systems engineering challenge: rectifying integrated product team requirements with performance issues in an evolutionary spiral development acquisition

    NASA Astrophysics Data System (ADS)

    Kuehl, C. Stephen

    2003-08-01

    Completing its final development and early deployment on the Navy's multi-role aircraft, the F/A-18 E/F Super Hornet, the SHAred Reconnaissance Pod (SHARP) provides the war fighter with the latest digital tactical reconnaissance (TAC Recce) Electro-Optical/Infrared (EO/IR) sensor system. The SHARP program is an evolutionary acquisition that used a spiral development process across a prototype development phase tightly coupled into overlapping Engineering and Manufacturing Development (EMD) and Low Rate Initial Production (LRIP) phases. Under a tight budget environment with a highly compressed schedule, SHARP challenged traditional acquisition strategies and systems engineering (SE) processes. Adopting tailored state-of-the-art systems engineering process models allowd the SHARP program to overcome the technical knowledge transition challenges imposed by a compressed program schedule. The program's original goal was the deployment of digital TAC Recce mission capabilities to the fleet customer by summer of 2003. Hardware and software integration technical challenges resulted from requirements definition and analysis activities performed across a government-industry led Integrated Product Team (IPT) involving Navy engineering and test sites, Boeing, and RTSC-EPS (with its subcontracted hardware and government furnished equipment vendors). Requirements development from a bottoms-up approach was adopted using an electronic requirements capture environment to clarify and establish the SHARP EMD product baseline specifications as relevant technical data became available. Applying Earned-Value Management (EVM) against an Integrated Master Schedule (IMS) resulted in efficiently managing SE task assignments and product deliveries in a dynamically evolving customer requirements environment. Application of Six Sigma improvement methodologies resulted in the uncovering of root causes of errors in wiring interconnectivity drawings, pod manufacturing processes, and avionics

  13. Polaron effects on the performance of light-harvesting systems: a quantum heat engine perspective

    NASA Astrophysics Data System (ADS)

    Xu, Dazhi; Wang, Chen; Zhao, Yang; Cao, Jianshu

    2016-02-01

    We explore energy transfer in a generic three-level system, which is coupled to three non-equilibrium baths. Built on the concept of quantum heat engine, our three-level model describes non-equilibrium quantum processes including light-harvesting energy transfer, nano-scale heat transfer, photo-induced isomerization, and photovoltaics in double quantum-dots. In the context of light-harvesting, the excitation energy is first pumped up by sunlight, then is transferred via two excited states which are coupled to a phonon bath, and finally decays to the reaction center. The efficiency of this process is evaluated by steady state analysis via a polaron-transformed master equation; thus the entire range of the system-phonon coupling strength can be covered. We show that the coupling with the phonon bath not only modifies the steady state, resulting in population inversion, but also introduces a finite steady state coherence which optimizes the energy transfer flux and efficiency. In the strong coupling limit, the steady state coherence disappears and the efficiency recovers the heat engine limit given by Scovil and Schultz-Dubois (1959 Phys. Rev. Lett. 2 262).

  14. High-Performance Bipropellant Engine

    NASA Technical Reports Server (NTRS)

    Biaglow, James A.; Schneider, Steven J.

    1999-01-01

    TRW, under contract to the NASA Lewis Research Center, has successfully completed over 10 000 sec of testing of a rhenium thrust chamber manufactured via a new-generation powder metallurgy. High performance was achieved for two different propellants, N2O4- N2H4 and N2O4 -MMH. TRW conducted 44 tests with N2O4-N2H4, accumulating 5230 sec of operating time with maximum burn times of 600 sec and a specific impulse Isp of 333 sec. Seventeen tests were conducted with N2O4-MMH for an additional 4789 sec and a maximum Isp of 324 sec, with a maximum firing duration of 700 sec. Together, the 61 tests totalled 10 019 sec of operating time, with the chamber remaining in excellent condition. Of these tests, 11 lasted 600 to 700 sec. The performance of radiation-cooled rocket engines is limited by their operating temperature. For the past two to three decades, the majority of radiation-cooled rockets were composed of a high-temperature niobium alloy (C103) with a disilicide oxide coating (R512) for oxidation resistance. The R512 coating practically limits the operating temperature to 1370 C. For the Earth-storable bipropellants commonly used in satellite and spacecraft propulsion systems, a significant amount of fuel film cooling is needed. The large film-cooling requirement extracts a large penalty in performance from incomplete mixing and combustion. A material system with a higher temperature capability has been matured to the point where engines are being readied for flight, particularly the 100-lb-thrust class engine. This system has powder rhenium (Re) as a substrate material with an iridium (Ir) oxidation-resistant coating. Again, the operating temperature is limited by the coating; however, Ir is capable of long-life operation at 2200 C. For Earth-storable bipropellants, this allows for the virtual elimination of fuel film cooling (some film cooling is used for thermal control of the head end). This has resulted in significant increases in specific impulse performance

  15. The size and performance effects of high lift system technology on a modern twin engine jet transport

    NASA Technical Reports Server (NTRS)

    Sullivan, R. L.

    1979-01-01

    The energy and economic benefits of low-speed aerodynamic system technology applied to a modern 200-passenger, 2000-nmi range, twin engine jet transport are reviewed. Results of a new method to design flap systems at flight Reynolds number are summarized. The study contains the airplane high lift configuration drag characteristics and design selection charts showing the effect of flap technology on the airplane size and performance. The study areas include: wing and flap geometry, climb and descent speed schedules with partial flap deflection, flap system technology, and augmented stability. The results compare the improvements in payload from a hot, high elevation airport.

  16. Innovative Double Bypass Engine for Increased Performance

    NASA Astrophysics Data System (ADS)

    Manoharan, Sanjivan

    Engines continue to grow in size to meet the current thrust requirements of the civil aerospace industry. Large engines pose significant transportation problems and require them to be split in order to be shipped. Thus, large amounts of time have been spent in researching methods to increase thrust capabilities while maintaining a reasonable engine size. Unfortunately, much of this research has been focused on increasing the performance and efficiencies of individual components while limited research has been done on innovative engine configurations. This thesis focuses on an innovative engine configuration, the High Double Bypass Engine, aimed at increasing fuel efficiency and thrust while maintaining a competitive fan diameter and engine length. The 1-D analysis was done in Excel and then compared to the results from Numerical Propulsion Simulation System (NPSS) software and were found to be within 4% error. Flow performance characteristics were also determined and validated against their criteria.

  17. System identification of jet engines

    SciTech Connect

    Sugiyama, N.

    2000-01-01

    System identification plays an important role in advanced control systems for jet engines, in which controls are performed adaptively using data from the actual engine and the identified engine. An identification technique for jet engine using the Constant Gain Extended Kalman Filter (CGEKF) is described. The filter is constructed for a two-spool turbofan engine. The CGEKF filter developed here can recognize parameter change in engine components and estimate unmeasurable variables over whole flight conditions. These capabilities are useful for an advanced Full Authority Digital Electric Control (FADEC). Effects of measurement noise and bias, effects of operating point and unpredicted performance change are discussed. Some experimental results using the actual engine are shown to evaluate the effectiveness of CGEKF filter.

  18. Performance Evaluation of Engineered Structured Sorbents for Atmosphere Revitalization Systems On Board Crewed Space Vehicles and Habitats

    NASA Technical Reports Server (NTRS)

    Howard, David F.; Perry, Jay L.; Knox, James C.; Junaedi, Christian; Roychoudhury, Subir

    2011-01-01

    Engineered structured (ES) sorbents are being developed to meet the technical challenges of future crewed space exploration missions. ES sorbents offer the inherent performance and safety attributes of zeolite and other physical adsorbents but with greater structural integrity and process control to improve durability and efficiency over packed beds. ES sorbent techniques that are explored include thermally linked and pressure-swing adsorption beds for water-save dehumidification and sorbent-coated metal meshes for residual drying, trace contaminant control, and carbon dioxide control. Results from sub-scale performance evaluations of a thermally linked pressure-swing adsorbent bed and an integrated sub-scale ES sorbent system are discussed.

  19. Concurrently adjusting interrelated control parameters to achieve optimal engine performance

    DOEpatents

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2015-12-01

    Methods and systems for real-time engine control optimization are provided. A value of an engine performance variable is determined, a value of a first operating condition and a value of a second operating condition of a vehicle engine are detected, and initial values for a first engine control parameter and a second engine control parameter are determined based on the detected first operating condition and the detected second operating condition. The initial values for the first engine control parameter and the second engine control parameter are adjusted based on the determined value of the engine performance variable to cause the engine performance variable to approach a target engine performance variable. In order to cause the engine performance variable to approach the target engine performance variable, adjusting the initial value for the first engine control parameter necessitates a corresponding adjustment of the initial value for the second engine control parameter.

  20. Engineering Lessons Learned and Systems Engineering Applications

    NASA Technical Reports Server (NTRS)

    Gill, Paul S.; Garcia, Danny; Vaughan, William W.

    2005-01-01

    Systems Engineering is fundamental to good engineering, which in turn depends on the integration and application of engineering lessons learned. Thus, good Systems Engineering also depends on systems engineering lessons learned from within the aerospace industry being documented and applied. About ten percent of the engineering lessons learned documented in the NASA Lessons Learned Information System are directly related to Systems Engineering. A key issue associated with lessons learned datasets is the communication and incorporation of this information into engineering processes. As part of the NASA Technical Standards Program activities, engineering lessons learned datasets have been identified from a number of sources. These are being searched and screened for those having a relation to Technical Standards. This paper will address some of these Systems Engineering Lessons Learned and how they are being related to Technical Standards within the NASA Technical Standards Program, including linking to the Agency's Interactive Engineering Discipline Training Courses and the life cycle for a flight vehicle development program.

  1. Performance of a multilevel quantum heat engine of an ideal N-particle Fermi system.

    PubMed

    Wang, Rui; Wang, Jianhui; He, Jizhou; Ma, Yongli

    2012-08-01

    We generalize the quantum heat engine (QHE) model which was first proposed by Bender et al. [J. Phys. A 33, 4427 (2000)] to the case in which an ideal Fermi gas with an arbitrary number N of particles in a box trap is used as the working substance. Besides two quantum adiabatic processes, the engine model contains two isoenergetic processes, during which the particles are coupled to energy baths at a high constant energy E(h) and a low constant energy E(c), respectively. Directly employing the finite-time thermodynamics, we find that the power output is enhanced by increasing particle number N (or decreasing minimum trap size L(A)) for given L(A) (or N), without reduction in the efficiency. By use of global optimization, the efficiency at possible maximum power output (EPMP) is found to be universal and independent of any parameter contained in the engine model. For an engine model with any particle-number N, the efficiency at maximum power output (EMP) can be determined under the condition that it should be closest to the EPMP. Moreover, we extend the heat engine to a more general multilevel engine model with an arbitrary 1D power-law potential. Comparison between our engine model and the Carnot cycle shows that, under the same conditions, the efficiency η = 1 - E(c)/E(h) of the engine cycle is bounded from above the Carnot value η(c) =1 - T(c)/T(h). PMID:23005748

  2. High Performance Arcjet Engines

    NASA Technical Reports Server (NTRS)

    Kennel, Elliot B.; Ivanov, Alexey Nikolayevich; Nikolayev, Yuri Vyacheslavovich

    1994-01-01

    This effort sought to exploit advanced single crystal tungsten-tantalum alloy material for fabrication of a high strength, high temperature arcjet anode. The use of this material is expected to result in improved strength, temperature resistance, and lifetime compared to state of the art polycrystalline alloys. In addition, the use of high electrical and thermal conductivity carbon-carbon composites was considered, and is believed to be a feasible approach. Highly conductive carbon-carbon composite anode capability represents enabling technology for rotating-arc designs derived from the Russian Scientific Research Institute of Thermal Processes (NIITP) because of high heat fluxes at the anode surface. However, for US designs the anode heat flux is much smaller, and thus the benefits are not as great as in the case of NIITP-derived designs. Still, it does appear that the tensile properties of carbon-carbon can be even better than those of single crystal tungsten alloys, especially when nearly-single-crystal fibers such as vapor grown carbon fiber (VGCF) are used. Composites fabricated from such materials must be coated with a refractory carbide coating in order to ensure compatibility with high temperature hydrogen. Fabrication of tungsten alloy single crystals in the sizes required for fabrication of an arcjet anode has been shown to be feasible. Test data indicate that the material can be expected to be at least the equal of W-Re-HfC polycrystalline alloy in terms of its tensile properties, and possibly superior. We are also informed by our colleagues at Scientific Production Association Luch (NP0 Luch) that it is possible to use Russian technology to fabricate polycrystalline W-Re-HfC or other high strength alloys if desired. This is important because existing engines must rely on previously accumulated stocks of these materials, and a fabrication capability for future requirements is not assured.

  3. An Introduction to Thermodynamic Performance Analysis of Aircraft Gas Turbine Engine Cycles Using the Numerical Propulsion System Simulation Code

    NASA Technical Reports Server (NTRS)

    Jones, Scott M.

    2007-01-01

    This document is intended as an introduction to the analysis of gas turbine engine cycles using the Numerical Propulsion System Simulation (NPSS) code. It is assumed that the analyst has a firm understanding of fluid flow, gas dynamics, thermodynamics, and turbomachinery theory. The purpose of this paper is to provide for the novice the information necessary to begin cycle analysis using NPSS. This paper and the annotated example serve as a starting point and by no means cover the entire range of information and experience necessary for engine performance simulation. NPSS syntax is presented but for a more detailed explanation of the code the user is referred to the NPSS User Guide and Reference document (ref. 1).

  4. System and method for improving performance of a fluid sensor for an internal combustion engine

    DOEpatents

    Kubinski, David; Zawacki, Garry

    2009-03-03

    A system and method for improving sensor performance of an on-board vehicle sensor, such as an exhaust gas sensor, while sensing a predetermined substance in a fluid flowing through a pipe include a structure for extending into the pipe and having at least one inlet for receiving fluid flowing through the pipe and at least one outlet generally opposite the at least one inlet, wherein the structure redirects substantially all fluid flowing from the at least one inlet to the sensor to provide a representative sample of the fluid to the sensor before returning the fluid through the at least one outlet.

  5. Automotive Stirling engine systems development

    NASA Technical Reports Server (NTRS)

    Richey, A. E.

    1984-01-01

    The objective of the Automotive Stirling Engine (ASE) program is to develop a Stirling engine for automotive use that provides a 30 percent improvement in fuel economy relative to a comparable internal-combustion engine while meeting emissions goals. This paper traces the engine systems' development efforts focusing on: (1) a summary of engine system performance for all Mod I engines; (2) the development, program conducted for the upgraded Mod I; and (3) vehicle systems work conducted to enhance vehicle fuel economy. Problems encountered during the upgraded Mod I test program are discussed. The importance of the EPA driving cycle cold-start penalty and the measures taken to minimize that penalty with the Mod II are also addressed.

  6. Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development and Performance Analysis

    NASA Technical Reports Server (NTRS)

    Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan; Kirchner, Robert; Engel, Carl D.

    2014-01-01

    The Space Launch System (SLS) base heating test is broken down into two test programs: (1) Pathfinder and (2) Main Test. The Pathfinder Test Program focuses on the design, development, hot-fire test and performance analyses of the 2% sub-scale SLS core-stage and booster element propulsion systems. The core-stage propulsion system is composed of four gaseous oxygen/hydrogen RS-25D model engines and the booster element is composed of two aluminum-based model solid rocket motors (SRMs). The first section of the paper discusses the motivation and test facility specifications for the test program. The second section briefly investigates the internal flow path of the design. The third section briefly shows the performance of the model RS-25D engines and SRMs for the conducted short duration hot-fire tests. Good agreement is observed based on design prediction analysis and test data. This program is a challenging research and development effort that has not been attempted in 40+ years for a NASA vehicle.

  7. Performance, Performance System, and High Performance System

    ERIC Educational Resources Information Center

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  8. Systems engineering management plans.

    SciTech Connect

    Rodriguez, Tamara S.

    2009-10-01

    The Systems Engineering Management Plan (SEMP) is a comprehensive and effective tool used to assist in the management of systems engineering efforts. It is intended to guide the work of all those involved in the project. The SEMP is comprised of three main sections: technical project planning and control, systems engineering process, and engineering specialty integration. The contents of each section must be tailored to the specific effort. A model outline and example SEMP are provided. The target audience is those who are familiar with the systems engineering approach and who have an interest in employing the SEMP as a tool for systems management. The goal of this document is to provide the reader with an appreciation for the use and importance of the SEMP, as well as provide a framework that can be used to create the management plan.

  9. Quantum Tunneling Affects Engine Performance.

    PubMed

    Som, Sibendu; Liu, Wei; Zhou, Dingyu D Y; Magnotti, Gina M; Sivaramakrishnan, Raghu; Longman, Douglas E; Skodje, Rex T; Davis, Michael J

    2013-06-20

    We study the role of individual reaction rates on engine performance, with an emphasis on the contribution of quantum tunneling. It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. The three-dimensional model includes detailed descriptions of the chemistry of a surrogate for a biodiesel fuel, as well as all the features of the engine, such as the liquid fuel spray and turbulence. This study is part of a larger investigation of how the features of the dynamics and potential energy surfaces of key reactions, as well as their reaction rate uncertainties, affect engine performance, and results in these directions are also presented here. PMID:26283246

  10. Performance and evaluation of gas-engine-driven split-system cooling equipment at the Willow Grove Naval Air Station

    SciTech Connect

    Armstrong, P.R.; Schmelzer, J.R.

    1997-01-01

    DOE`s Federal Energy Management Program supports efforts to reduce energy use and associated expenditures within the federal sector; one such effort, the New Technology Demonstration Program (NTDP)(formerly the Test Bed Demonstration program), seeks to evaluate new energy saving US technologies and secure their more timely adoption by the federal government. This report describes the field evaluation conducted to examine the performance of a 15-ton natural-gas-engine- driven, split-system, air-conditioning unit. The unit was installed at a multiple-use building at Willow Grove Naval Air Station, a regular and reserve training facility north of Philadelphia, and its performance was monitored under the NTDP.

  11. High-Performance SiC/SiC Ceramic Composite Systems Developed for 1315 C (2400 F) Engine Components

    NASA Technical Reports Server (NTRS)

    DiCarlo, James A.; Yun, Hee Mann; Morscher, Gregory N.; Bhatt, Ramakrishna T.

    2004-01-01

    As structural materials for hot-section components in advanced aerospace and land-based gas turbine engines, silicon carbide (SiC) ceramic matrix composites reinforced by high performance SiC fibers offer a variety of performance advantages over current bill-of-materials, such as nickel-based superalloys. These advantages are based on the SiC/SiC composites displaying higher temperature capability for a given structural load, lower density (approximately 30- to 50-percent metal density), and lower thermal expansion. These properties should, in turn, result in many important engine benefits, such as reduced component cooling air requirements, simpler component design, reduced support structure weight, improved fuel efficiency, reduced emissions, higher blade frequencies, reduced blade clearances, and higher thrust. Under the NASA Ultra-Efficient Engine Technology (UEET) Project, much progress has been made at the NASA Glenn Research Center in identifying and optimizing two highperformance SiC/SiC composite systems. The table compares typical properties of oxide/oxide panels and SiC/SiC panels formed by the random stacking of balanced 0 degrees/90 degrees fabric pieces reinforced by the indicated fiber types. The Glenn SiC/SiC systems A and B (shaded area of the table) were reinforced by the Sylramic-iBN SiC fiber, which was produced at Glenn by thermal treatment of the commercial Sylramic SiC fiber (Dow Corning, Midland, MI; ref. 2). The treatment process (1) removes boron from the Sylramic fiber, thereby improving fiber creep, rupture, and oxidation resistance and (2) allows the boron to react with nitrogen to form a thin in situ grown BN coating on the fiber surface, thereby providing an oxidation-resistant buffer layer between contacting fibers in the fabric and the final composite. The fabric stacks for all SiC/SiC panels were provided to GE Power Systems Composites for chemical vapor infiltration of Glenn designed BN fiber coatings and conventional SiC matrices

  12. Developing Data System Engineers

    NASA Astrophysics Data System (ADS)

    Behnke, J.; Byrnes, J. B.; Kobler, B.

    2011-12-01

    In the early days of general computer systems for science data processing, staff members working on NASA's data systems would most often be hired as mathematicians. Computer engineering was very often filled by those with electrical engineering degrees. Today, the Goddard Space Flight Center has special position descriptions for data scientists or as they are more commonly called: data systems engineers. These staff members are required to have very diverse skills, hence the need for a generalized position description. There is always a need for data systems engineers to develop, maintain and operate the complex data systems for Earth and space science missions. Today's data systems engineers however are not just mathematicians, they are computer programmers, GIS experts, software engineers, visualization experts, etc... They represent many different degree fields. To put together distributed systems like the NASA Earth Observing Data and Information System (EOSDIS), staff are required from many different fields. Sometimes, the skilled professional is not available and must be developed in-house. This paper will address the various skills and jobs for data systems engineers at NASA. Further it explores how to develop staff to become data scientists.

  13. Identifying Engineering, Clinical and Patient's Metrics for Evaluating and Quantifying Performance of Brain-Machine Interface (BMI) Systems

    PubMed Central

    Contreras-Vidal, Jose L.

    2015-01-01

    Brain-machine interface (BMI) devices have unparalleled potential to restore functional movement capabilities to stroke, paralyzed and amputee patients. Although BMI systems have achieved success in a handful of investigative studies, translation of closed-loop neuroprosthetic devices from the laboratory to the market is challenged by gaps in the scientific data regarding long-term device reliability and safety, uncertainty in the regulatory, market and reimbursement pathways, lack of metrics for evaluating and quantifying performance in BMI systems, as well as patient-acceptance challenges that impede their fast and effective translation to the end user. This review focuses on the identification of engineering, clinical and user's BMI metrics for new and existing BMI applications. PMID:26330746

  14. Airbreathing Pulse Detonation Engine Performance

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.; Yungster, Shaye

    2002-01-01

    This paper presents performance results for pulse detonation engines (PDE) taking into account the effects of dissociation and recombination. The amount of sensible heat recovered through recombination in the PDE chamber and exhaust process was found to be significant. These results have an impact on the specific thrust, impulse and fuel consumption of the PDE.

  15. Airbreathing Pulse Detonation Engine Performance

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.; Yungster, Shaye

    2002-01-01

    This paper presents performance results for pulse detonation engines taking into account the effects of dissociation and recombination. The amount of sensible heat recovered through recombination in the PDE chamber and exhaust process was found to be significant. These results have an impact on the specific thrust, impulse and fuel consumption of the PDE.

  16. Computational Intelligence and Its Impact on Future High-Performance Engineering Systems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler)

    1996-01-01

    This document contains presentations from the joint UVA/NASA Workshop on Computational Intelligence held at the Virginia Consortium of Engineering and Science Universities, Hampton, Virginia, June 27-28, 1995. The presentations addressed activities in the areas of fuzzy logic, neural networks, and evolutionary computations. Workshop attendees represented NASA, the National Science Foundation, the Department of Energy, National Institute of Standards and Technology (NIST), the Jet Propulsion Laboratory, industry, and academia. The workshop objectives were to assess the state of technology in the Computational intelligence area and to provide guidelines for future research.

  17. Rotary engine cooling system

    NASA Technical Reports Server (NTRS)

    Jones, Charles (Inventor); Gigon, Richard M. (Inventor); Blum, Edward J. (Inventor)

    1985-01-01

    A rotary engine has a substantially trochoidal-shaped housing cavity in which a rotor planetates. A cooling system for the engine directs coolant along a single series path consisting of series connected groups of passages. Coolant enters near the intake port, passes downwardly and axially through the cooler regions of the engine, then passes upwardly and axially through the hotter regions. By first flowing through the coolest regions, coolant pressure is reduced, thus reducing the saturation temperature of the coolant and thereby enhancing the nucleate boiling heat transfer mechanism which predominates in the high heat flux region of the engine during high power level operation.

  18. V-TECS Guide for Automobile Engine Performance Technician.

    ERIC Educational Resources Information Center

    Meyer, Calvin F.; Benson, Robert T.

    This guide is intended to assist teachers responsible for instructing future auto engine performance technicians. The following topics are covered: diagnosing engine performance problems, ignition system problems, fuel system problems, mechanically related performance problems, emission control system problems, and electronic control systems;…

  19. Aircraft Engine Systems

    NASA Technical Reports Server (NTRS)

    Veres, Joseph

    2001-01-01

    This report outlines the detailed simulation of Aircraft Turbofan Engine. The objectives were to develop a detailed flow model of a full turbofan engine that runs on parallel workstation clusters overnight and to develop an integrated system of codes for combustor design and analysis to enable significant reduction in design time and cost. The model will initially simulate the 3-D flow in the primary flow path including the flow and chemistry in the combustor, and ultimately result in a multidisciplinary model of the engine. The overnight 3-D simulation capability of the primary flow path in a complete engine will enable significant reduction in the design and development time of gas turbine engines. In addition, the NPSS (Numerical Propulsion System Simulation) multidisciplinary integration and analysis are discussed.

  20. Radiation effect on rocket engine performance

    NASA Technical Reports Server (NTRS)

    Chiu, Huei-Huang

    1988-01-01

    The effects of radiation on the performance of modern rocket propulsion systems operating at high pressure and temperature were recognized as a key issue in the design and operation of various liquid rocket engines of the current and future generations. Critical problem areas of radiation coupled with combustion of bipropellants are assessed and accounted for in the formulation of a universal scaling law incorporated with a radiation-enhanced vaporization combustion model. Numerical algorithms are developed and the pertaining data of the Variable Thrust Engine (VTE) and Space Shuttle Main Engine (SSME) are used to conduct parametric sensitivity studies to predict the principal intercoupling effects of radiation. The analysis reveals that low enthalpy engines, such as the VTE, are vulnerable to a substantial performance set back by the radiative loss, whereas the performance of high enthalpy engines such as the SSME, are hardly affected over a broad range of engine operation. Additionally, combustion enhancement by the radiative heating of the propellant has a significant impact in those propellants with high absorptivity. Finally, the areas of research related with radiation phenomena in bipropellant engines are identified.

  1. Combustion engine system

    NASA Technical Reports Server (NTRS)

    Houseman, John (Inventor); Voecks, Gerald E. (Inventor)

    1986-01-01

    A flow through catalytic reactor which selectively catalytically decomposes methanol into a soot free hydrogen rich product gas utilizing engine exhaust at temperatures of 200 to 650 C to provide the heat for vaporizing and decomposing the methanol is described. The reactor is combined with either a spark ignited or compression ignited internal combustion engine or a gas turbine to provide a combustion engine system. The system may be fueled entirely by the hydrogen rich gas produced in the methanol decomposition reactor or the system may be operated on mixed fuels for transient power gain and for cold start of the engine system. The reactor includes a decomposition zone formed by a plurality of elongated cylinders which contain a body of vapor permeable, methanol decomposition catalyst preferably a shift catalyst such as copper-zinc.

  2. Engineering Lessons Learned and Systems Engineering Applications

    NASA Technical Reports Server (NTRS)

    Gill, Paul S.; Garcia, Danny; Vaughan, William W.

    2005-01-01

    Systems Engineering is fundamental to good engineering, which in turn depends on the integration and application of engineering lessons learned and technical standards. Thus, good Systems Engineering also depends on systems engineering lessons learned from within the aerospace industry being documented and applied. About ten percent of the engineering lessons learned documented in the NASA Lessons Learned Information System are directly related to Systems Engineering. A key issue associated with lessons learned datasets is the communication and incorporation of this information into engineering processes. Systems Engineering has been defined (EINIS-632) as "an interdisciplinary approach encompassing the entire technical effort to evolve and verify an integrated and life-cycle balanced set of system people, product, and process solutions that satisfy customer needs". Designing reliable space-based systems has always been a goal for NASA, and many painful lessons have been learned along the way. One of the continuing functions of a system engineer is to compile development and operations "lessons learned" documents and ensure their integration into future systems development activities. They can produce insights and information for risk identification identification and characterization. on a new project. Lessons learned files from previous projects are especially valuable in risk

  3. Thermoelectrically cooled cloud physics expansion chamber. [systems engineering and performance prediction

    NASA Technical Reports Server (NTRS)

    Buist, R. J.

    1977-01-01

    The design and fabrication of a thermoelectric chiller for use in chilling a liquid reservoir is described. Acceptance test results establish the accuracy of the thermal model and predict the unit performance under various conditions required by the overall spacelab program.

  4. High-end-Computer System Performance: Science and Engineering - Final Report

    SciTech Connect

    Hollingsworth, Jeffrey K.

    2012-01-27

    This report summarizes the research conducted as part of the UMD effort of the multi-site PERC project. This project developed and enhanced the Dyninst instrumentation system and the Active Harmony auto-tuning framework.

  5. Yucca Mountain near-field environment considerations for engineered barrier system design and performance

    SciTech Connect

    Wilder, D.G.

    1991-05-01

    The United States Department of Energy (DOE) is investigating the suitability of Yucca Mountain (YM) as a potential site for the nation`s first High-Level Nuclear Waste Repository. This responsibility includes materials testing and selections, design criteria development, waste form characterizations, performance assessments, and Near-Field (NF) environment characterization. These areas of responsibility are interrelated and to a large extent depend on environmental conditions surrounding the EBS components. The focus of this paper is to discuss what is currently known about the NF environment, particularly those aspects whose interaction with EBS components have significant impacts on the performance of the EBS and its ability to contribute to the isolation of radioactive waste. Reference designs and design/processes assumptions are used to evaluate the expected NF environmental conditions. This report will not focus on providing parameter values but rather on the processes that influence those parameters and on the impacts of those parameters on the performance of EBS components. Where values are given, they should be viewed as typical of YM as a whole but not necessarily representative of the actual NF environment conditions that surround the EBS components. 19 refs., 6 figs.

  6. Tethered Satellite System (TSS-1R)-Post Flight (STS-75) Engineering Performance Report

    NASA Technical Reports Server (NTRS)

    Lavoie, Anthony R.

    1996-01-01

    The first mission of the Tethered Satellite deployer was flown onboard Atlantis in 1992 during the Space Transportation System (STS) flight STS-46. Due to a mechanical interference with the level wind mechanism the satellite was only Deployed to 256 m rather than the planned 20,000 m. Other problems were also experienced during the STS-46 flight and several modifications were made to the Deployer and Satellite. STS-75 was a reflight of the Tethered Satellite System 1 (TSS-1) designated as Tethered Satellite System 1 Reflight (TSS-1 R) onboard Columbia. As on STS-46, the TSS payload consisted of the Deployer, the Satellite, 3 cargo bay mounted experiments: Shuttle Electrodynamic Tether System (SETS), Shuttle Potential and Return Electron Experiment (SPREE), Deployer Core Equipment (DCORE) 4 Satellite mounted experiments: Research on Electrodynamics Tether Effects (RETE), Research on Orbital Plasma Electrodynamics (ROPE), Satellite Core Instruments (SCORE), Tether Magnetic Field Experiment (TEMAG) and an aft flight deck camera: Tether Optical Phenomena Experiment (TOP). Following successful pre-launch, launch and pre-deployment orbital operations, the Deployer deployed the Tethered Satellite to 19,695 m at which point the tether broke within the Satellite Deployment Boom (SDB). The planned length for On-Station I (OST1) was 20,700 m The Satellite flew away from the Orbiter with the tether attached. The satellite was "safed" and placed in a limited power mode via the RF link. The Satellite was contacted periodically during overflights of ground stations. Cargo bay science activities continued for the period of time allocated to TSS-1 R operations.

  7. Performance Engineering in the Community Atmosphere Model

    SciTech Connect

    Worley, P; Mirin, A; Drake, J; Sawyer, W

    2006-05-30

    The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years.

  8. Enhanced Massive Visualization of Engines Performance

    NASA Astrophysics Data System (ADS)

    Rostand, N. D.; Eglantine, H.; Jerôme, L.

    2012-05-01

    Today, we are witnessing an increasing complexity of transport in order to deal with requirements of safety, security, reliability and efficiency. Such transport is generally equipped with drive systems; it is nevertheless for engine manufacturers to overcome the performance requirements of energy efficiency throughout their operations. To this end, this article proposes a performance monitoring solution for a large fleet of engines in operation. It uses a pre-calibrated physical model developed by the engine manufacturer regarding the performance objectives as reference. The physical model is firstly decomposed into critical performance modules, and is secondly updated on current observations extracted at specific predefined operating conditions in order to derive residual errors status of each engine tested. Through a process of standardization of those contextual differences remaining, the solution offers a synthesis mapping to visualize the evolution of performance of each engine throughout its operations. This article describes the theoretical methodology of implementation mainly based on universal mathematical foundations, and vindicates the interests of its industrialization in the light of the proactive findings.

  9. Effects of compositional changes on the performance of a thermal barrier coating system. [for aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Stecura, S.

    1979-01-01

    Systems consisting of Ni-base bond coatings containing about 16Cr, 6Al, and from 0.15 to 1.08Y (all in wt %) and zirconium oxide layers containing from 4.0 to 24.4Y2O3 were evaluated for suitability as thermal barrier systems for advanced aircraft gas turbine engine components. The evaluations were performed in a cyclic furnace between 990 and 280 C as well as between 1095 and 280 C on solid specimens; in a natural gas-oxygen torch rig between about 1200 and 100 C on solid specimens and up to 1580 C surface temperatures on air-cooled blades; and in a Mach 1.0 burner rig up to 1570 C surface temperatures on air-cooled blades. The data indicate that the best systems consist of combinations involving the Ni-16.4Cr-5.1Al-0.15Y and Ni-17.0Cr-5.4Al-0.35Y bond coatings and the 6.2Y2O3- and 7.9Y2O3- (all in wt %) stabilized zirconium oxide layers.

  10. Systems engineering and analysis

    SciTech Connect

    Blanchard, B.S.; Fabrycky, W.J.

    1981-01-01

    An introduction to systems is provided and tools for systems analysis are considered, taking into account system definitions and concepts, approaches for bringing systems into being, models in systems analysis, economic analysis techniques, mathematical modeling and optimization, probability and statistics, queuing theory and analysis, and control concepts and techniques. The system design process is discussed along with the design for operational feasibility, systems engineering management, and system design case studies. Attention is given to conceptual design, preliminary system design, detail design and development, system test and evaluation, design for reliability, design for maintainability, design for supportability, design for economic feasibility, communication system design, finite population system design, energy storage system design, and procurement-inventory system design.

  11. International Space Station Sustaining Engineering: A Ground-Based Test Bed for Evaluating Integrated Environmental Control and Life Support System and Internal Thermal Control System Flight Performance

    NASA Technical Reports Server (NTRS)

    Ray, Charles D.; Perry, Jay L.; Callahan, David M.

    2000-01-01

    As the International Space Station's (ISS) various habitable modules are placed in service on orbit, the need to provide for sustaining engineering becomes increasingly important to ensure the proper function of critical onboard systems. Chief among these are the Environmental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). Without either, life onboard the ISS would prove difficult or nearly impossible. For this reason, a ground-based ECLSS/ITCS hardware performance simulation capability has been developed at NASA's Marshall Space Flight Center. The ECLSS/ITCS Sustaining Engineering Test Bed will be used to assist the ISS Program in resolving hardware anomalies and performing periodic performance assessments. The ISS flight configuration being simulated by the test bed is described as well as ongoing activities related to its preparation for supporting ISS Mission 5A. Growth options for the test facility are presented whereby the current facility may be upgraded to enhance its capability for supporting future station operation well beyond Mission 5A. Test bed capabilities for demonstrating technology improvements of ECLSS hardware are also described.

  12. An analysis of cryotrap heat exchanger performance test data (400 area) and recommendations for a system to handle Apollo RCS engines

    NASA Technical Reports Server (NTRS)

    Rakow, A.

    1983-01-01

    The current arrangement of a Platecoil heat exchanger which uses LN2 on the inside of parallel tubes, in counter flow to the test cell engine exhaust gases which are drawn through a box surrounding the plates by the existing vacuum blowers is examined. As a result of inadequate performance and special test data it was decided to redesign the system to accommodate an Apollo RCS engine.

  13. Intelligent Engine Systems: Bearing System

    NASA Technical Reports Server (NTRS)

    Singh, Arnant P.

    2008-01-01

    The overall requirements necessary for sensing bearing distress and the related criteria to select a particular rotating sensor were established during the phase I. The current phase II efforts performed studies to evaluate the Robustness and Durability Enhancement of the rotating sensors, and to design, and develop the Built-in Telemetry System concepts for an aircraft engine differential sump. A generic test vehicle that can test the proposed bearing diagnostic system was designed, developed, and built. The Timken Company, who also assisted with testing the GE concept of using rotating sensors for the differential bearing diagnostics during previous phase, was selected as a subcontractor to assist General Electric (GE) for the design, and procurement of the test vehicle. A purchase order was prepared to define the different sub-tasks, and deliverables for this task. The University of Akron was selected to provide the necessary support for installing, and integrating the test vehicle with their newly designed test facility capable of simulating the operating environment for the planned testing. The planned testing with good and damaged bearings will be on hold pending further continuation of this effort during next phase.

  14. Readings in Systems Engineering

    NASA Technical Reports Server (NTRS)

    Hoban, Francis T. (Editor); Lawbaugh, William M. (Editor)

    1993-01-01

    This present collection was inspired by seven papers prepared by the NASA Alumni League, illustrating the members' systems engineering experience. These papers make up the heart of this collection. We have supplemented them with papers describing industry processes and other governmental practices to illustrate the diversity of systems engineering as it is formulated and practiced. This is one discipline that clearly benefits from cross-fertilization and infusion of new ideas. There is also a wide variety of tools and techniques described herein, some standard and some unique.

  15. Advanced System for Process Engineering

    Energy Science and Technology Software Center (ESTSC)

    1992-02-01

    ASPEN (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes. ASPEN can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations. It is supported by a comprehensive physical property system for computationmore » of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The ASPEN Input Language is oriented towards process engineers.« less

  16. Selection of a computer code for Hanford low-level waste engineered-system performance assessment. Revision 1

    SciTech Connect

    McGrail, B.P.; Bacon, D.H.

    1998-02-01

    Planned performance assessments for the proposed disposal of low-activity waste (LAW) glass produced from remediation of wastes stored in underground tanks at Hanford, Washington will require calculations of radionuclide release rates from the subsurface disposal facility. These calculations will be done with the aid of computer codes. The available computer codes with suitable capabilities at the time Revision 0 of this document was prepared were ranked in terms of the feature sets implemented in the code that match a set of physical, chemical, numerical, and functional capabilities needed to assess release rates from the engineered system. The needed capabilities were identified from an analysis of the important physical and chemical processes expected to affect LAW glass corrosion and the mobility of radionuclides. This analysis was repeated in this report but updated to include additional processes that have been found to be important since Revision 0 was issued and to include additional codes that have been released. The highest ranked computer code was found to be the STORM code developed at PNNL for the US Department of Energy for evaluation of arid land disposal sites.

  17. Engine systems analysis results of the Space Shuttle Main Engine redesigned powerhead initial engine level testing

    NASA Astrophysics Data System (ADS)

    Sander, Erik J.; Gosdin, Dennis R.

    1992-07-01

    Engineers regularly analyze SSME ground test and flight data with respect to engine systems performance. Recently, a redesigned SSME powerhead was introduced to engine-level testing in part to increase engine operational margins through optimization of the engine internal environment. This paper presents an overview of the MSFC personnel engine systems analysis results and conclusions reached from initial engine level testing of the redesigned powerhead, and further redesigns incorporated to eliminate accelerated main injector baffle and main combustion chamber hot gas wall degradation. The conclusions are drawn from instrumented engine ground test data and hardware integrity analysis reports and address initial engine test results with respect to the apparent design change effects on engine system and component operation.

  18. NASA Systems Engineering Handbook

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This handbook is intended to provide general guidance and information on systems engineering that will be useful to the NASA community. It provides a generic description of Systems Engineering (SE) as it should be applied throughout NASA. A goal of the handbook is to increase awareness and consistency across the Agency and advance the practice of SE. This handbook provides perspectives relevant to NASA and data particular to NASA. The coverage in this handbook is limited to general concepts and generic descriptions of processes, tools, and techniques. It provides information on systems engineering best practices and pitfalls to avoid. There are many Center-specific handbooks and directives as well as textbooks that can be consulted for in-depth tutorials. This handbook describes systems engineering as it should be applied to the development and implementation of large and small NASA programs and projects. NASA has defined different life cycles that specifically address the major project categories, or product lines, which are: Flight Systems and Ground Support (FS&GS), Research and Technology (R&T), Construction of Facilities (CoF), and Environmental Compliance and Restoration (ECR). The technical content of the handbook provides systems engineering best practices that should be incorporated into all NASA product lines. (Check the NASA On-Line Directives Information System (NODIS) electronic document library for applicable NASA directives on topics such as product lines.) For simplicity this handbook uses the FS&GS product line as an example. The specifics of FS&GS can be seen in the description of the life cycle and the details of the milestone reviews. Each product line will vary in these two areas; therefore, the reader should refer to the applicable NASA procedural requirements for the specific requirements for their life cycle and reviews. The engineering of NASA systems requires a systematic and disciplined set of processes that are applied recursively and

  19. RDD-100 and the systems engineering process

    NASA Technical Reports Server (NTRS)

    Averill, Robert D.

    1994-01-01

    An effective systems engineering approach applied through the project life cycle can help Langley produce a better product. This paper demonstrates how an enhanced systems engineering process for in-house flight projects assures that each system will achieve its goals with quality performance and within planned budgets and schedules. This paper also describes how the systems engineering process can be used in combination with available software tools.

  20. A Collaborative Analysis Tool for Integrating Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Thomas Troy; Alexander, Reginald

    1999-01-01

    Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. The deficiencies in the scramjet powered concept led to a revival of interest in Rocket-Based Combined-Cycle (RBCC) propulsion systems. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. At this point the transitions to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scram4jet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance.

  1. PV System Performance and Standards

    SciTech Connect

    Osterwald, C. R.

    2005-11-01

    This paper presents a brief overview of the status and accomplishments during fiscal year (FY) 2005 of the Photovoltaic (PV) System Performance and Standards Subtask, which is part of the PV Systems Engineering Project (a joint NREL-Sandia project).

  2. Factors of airplane engine performance

    NASA Technical Reports Server (NTRS)

    Gage, Victor R

    1921-01-01

    This report is based upon an analysis of a large number of airplane-engine tests. It contains the results of a search for fundamental relations between many variables of engine operation. The data used came from over 100 groups of tests made upon several engines, primarily for military information. The types of engines were the Liberty 12 and three models of the Hispano-Suiza. The tests were made in the altitude chamber, where conditions simulated altitudes up to about 30,000 feet, with engine speeds ranging from 1,200 to 2,200 r.p.m. The compression ratios of the different engines ranged from under 5 to over 8 to 1. The data taken on the tests were exceptionally complete, including variations of pressure and temperature, besides the brake and friction torques, rates of fuel and air consumption, the jacket and exhaust heat losses.

  3. A road map for implementing systems engineering

    SciTech Connect

    Dean, F.F.; Bentz, B.; Bahill, A.T.

    1997-02-01

    Studies by academia, industry, and government indicate that applying a sound systems engineering process to development programs is an important tool for preventing cost and schedule overruns and performance deficiencies. There is an enormous body of systems engineering knowledge. Where does one start? How can the principles of systems engineering be applied in the Sandia environment? This road map is intended to be an aid to answering these questions.

  4. Covariance of engineering management characteristics with engineering employee performance

    NASA Astrophysics Data System (ADS)

    Hesketh, Andrew Arthur

    1998-12-01

    As business in the 1990's grapples with the impact of continuous improvement and quality to meet market demands, there is an increased need to improve the leadership capabilities of our managers. Engineers have indicated desire for certain managerial characteristics in their leadership but there have been no studies completed that approached the problem of determining what managerial characteristics were best at improving employee performance. This study addressed the idea of identifying certain managerial characteristics that enhance employee performance. In the early 1990's, McDonnell Douglas Aerospace in St. Louis used a forced distribution system and allocated 35% of its employees into a "exceeds expectations" category and 60% into a "meets expectations" category. A twenty-question 5 point Likert scale survey on managerial capabilities was administered to a sample engineering population that also obtained their "expectations" category. A single factor ANOVA on the survey results determined a statistical difference between the "exceeds" and "meets" employees with four of the managerial capability questions. The "exceeds expectations" employee indicated that supervision did a better job of supporting subordinate development, clearly communicating performance expectations, and providing timely performance feedback when compared to the "meets expectations" employee. The "meets expectations" employee felt that their opinions, when different from their supervisor's, were more often ignored when compared to the "exceeds expectations" employee. These four questions relate to two specific managerial characteristics, "gaining (informal) authority and support" or "control" characteristic and "providing assistance and guidance" or "command" characteristic, that can be emphasized in managerial training programs.

  5. A Collaborative Analysis Tool for Integrated Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Thomas Troy; Alexander, Reginald; Landrum, Brian

    2000-01-01

    Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. Then there is a transition to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scramjet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance. To adequately determine the performance of the engine/vehicle, the Hypersonic Flight Inlet Model (HYFIM) module was designed to interface with the RBCC

  6. Marine Engine Mechanics. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are presented for each of ten terminal objectives for a two-semester course (3 hours daily). This 540-hour intermediate course includes advanced troubleshooting techniques on outboard marine engines, inboard-outboard marine engines, inboard marine engines, boat…

  7. Looking ahead in systems engineering

    NASA Technical Reports Server (NTRS)

    Feigenbaum, Donald S.

    1966-01-01

    Five areas that are discussed in this paper are: (1) the technological characteristics of systems engineering; (2) the analytical techniques that are giving modern systems work its capability and power; (3) the management, economics, and effectiveness dimensions that now frame the modern systems field; (4) systems engineering's future impact upon automation, computerization and managerial decision-making in industry - and upon aerospace and weapons systems in government and the military; and (5) modern systems engineering's partnership with modern quality control and reliability.

  8. Energy Efficient Engine core design and performance report

    NASA Technical Reports Server (NTRS)

    Stearns, E. Marshall

    1982-01-01

    The Energy Efficient Engine (E3) is a NASA program to develop fuel saving technology for future large transport aircraft engines. Testing of the General Electric E3 core showed that the core component performance and core system performance necessary to meet the program goals can be achieved. The E3 core design and test results are described.

  9. Tank waste remediation system engineering plan

    SciTech Connect

    Rifaey, S.H.

    1998-01-09

    This Engineering Plan describes the engineering process and controls that will be in place to support the Technical Baseline definition and manage its evolution and implementation to the field operations. This plan provides the vision for the engineering required to support the retrieval and disposal mission through Phase 1 and 2, which includes integrated data management of the Technical Baseline. Further, this plan describes the approach for moving from the ``as is`` condition of engineering practice, systems, and facilities to the desired ``to be`` configuration. To make this transition, Tank Waste Remediation System (TWRS) Engineering will become a center of excellence for TWRS which,will perform engineering in the most effective manner to meet the mission. TWRS engineering will process deviations from sitewide systems if necessary to meet the mission most effectively.

  10. Engine system assessment study using Martian propellants

    NASA Technical Reports Server (NTRS)

    Pelaccio, Dennis; Jacobs, Mark; Scheil, Christine; Collins, John

    1992-01-01

    A top-level feasibility study was conducted that identified and characterized promising chemical propulsion system designs which use two or more of the following propellant combinations: LOX/H2, LOX/CH4, and LOX/CO. The engine systems examined emphasized the usage of common subsystem/component hardware where possible. In support of this study, numerous mission scenarios were characterized that used various combinations of Earth, lunar, and Mars propellants to establish engine system requirements to assess the promising engine system design concept examined, and to determine overall exploration leverage of such systems compared to state-of-the-art cryogenic (LOX/H2) propulsion systems. Initially in the study, critical propulsion system technologies were assessed. Candidate expander and gas generator cycle LOX/H2/CO, LOX/H2/CH4, and LOX/CO/CH4 engine system designs were parametrically evaluated. From this evaluation baseline, tripropellant Mars Transfer Vehicle (MTV) LOX cooled and bipropellant Lunar Excursion Vehicle (LEV) and Mars Excursion Vehicle (MEV) engine systems were identified. Representative tankage designs for a MTV were also investigated. Re-evaluation of the missions using the baseline engine design showed that in general the slightly lower performance, smaller, lower weight gas generator cycle-based engines required less overall mission Mars and in situ propellant production (ISPP) infrastructure support compared to the larger, heavier, higher performing expander cycle engine systems.

  11. Engineering the LISA Project: Systems Engineering Challenges

    NASA Technical Reports Server (NTRS)

    Evans, Jordan P.

    2006-01-01

    The Laser Interferometer Space Antenna (LISA) is a joint NASA/ESA mission to detect and measure gravitational waves with periods from 1 s to 10000 s. The systems engineering challenges of developing a giant interferometer, 5 million kilometers on a side, an: numerous. Some of the key challenges are presented in this paper. The organizational challenges imposed by sharing the engineering function between three centers (ESA ESTEC, NASA GSFC, and JPL) across nine time zones are addressed. The issues and approaches to allocation of the acceleration noise and measurement sensitivity budget terms across a traditionally decomposed system are discussed. Additionally, using LISA to detect gravitational waves for the first time presents significant data analysis challenges, many of which drive the project system design. The approach to understanding the implications of science data analysis on the system is also addressed.

  12. Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

    NASA Technical Reports Server (NTRS)

    Hall, Phil; Whitfield, Susan

    2011-01-01

    This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

  13. Systems Engineering of Electric and Hybrid Vehicles

    NASA Technical Reports Server (NTRS)

    Kurtz, D. W.; Levin, R. R.

    1986-01-01

    Technical paper notes systems engineering principles applied to development of electric and hybrid vehicles such that system performance requirements support overall program goal of reduced petroleum consumption. Paper discusses iterative design approach dictated by systems analyses. In addition to obvious peformance parameters of range, acceleration rate, and energy consumption, systems engineering also considers such major factors as cost, safety, reliability, comfort, necessary supporting infrastructure, and availability of materials.

  14. Engine diagnostics program: CF6-50 engine performance deterioration

    NASA Technical Reports Server (NTRS)

    Wulf, R. H.

    1980-01-01

    Cockpit cruise recordings and test cell data in conjunction with hardware inspection results from airline overhaul shops were analyzed to define the extent and magnitude of performance deterioration of the General Electric CF6-50 high bypass turbofan engine. The magnitude of short term deterioration was isolated from the long term, and the individual damage mechanisms that were the cause for the majority of the performance deterioration was identified. It was determined that the long term engine performance deterioration characteristics were different for the 3 aircraft types currently powered by the CF6-50 engine, but these differences were due to operational considerations (flight length and takeoff derate) and not to differences associated with the aircraft type. Unrestored losses, that is, performance deterioration which remains after engine refurbishment, represents over 70 percent of the total performance deterioration at engine shop visit. Superficial damage, such as, increased surface roughness, leading edge shape changes on airfoils, and increases in the average clearances between rotating and stationary components is the major contributor to these losses. Seventy one percent of the unrestored losses are cost effective to restore, and if implemented could reduce fuel consumed by CF6-50 engines by 26 million gallons in 1980.

  15. System design and performance prediction of a free-piston Stirling engine/magnetic coupling/compressor assembly in a gas residential heat pump

    NASA Astrophysics Data System (ADS)

    Chen, G.; Beale, W. T.

    Based on the previous evaluation of a magnetic coupling and the described system-design targets, a gas fired free piston Stirling engine/magnetic coupling/compressor (FPSE/MC/C) assembly as a power module for a residential heat pump application was designed and analyzed. A porous combustor/FPSE/magnetic coupling/variable gas control spring/reciprocating compressor assembly was the design selected. Based on the system characteristics, design efforts are described on the following issues: (1) design of a combustor allowing low pressure of natural gas supply; (2) the means to achieve engine power-load matching; (3) the method to maintain the assembly as a resonant system tuning over a wide range of operating conditions; (4) the design of an engine/coupling structure to minimize the magnet mass without sacrificing its mechanical properties; and (5) compressor load capacity modulation. The system analysis and the system performance, which is analytically predicted and described, indicate all the system design goals can be met leading to a strong recommendation for further development.

  16. Advanced System for Process Engineering

    Energy Science and Technology Software Center (ESTSC)

    1998-09-14

    PRO ASPEN/PC1.0 (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes and has been ported to run on a PC. PRO ASPEN/PC1.0 can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations.more » It is supported by a comprehensive physical property system for computation of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The PRO ASPEN/PC1.0 Input Language is oriented towards process engineers.« less

  17. Intelligent Engine Systems: Acoustics

    NASA Technical Reports Server (NTRS)

    Wojno, John; Martens, Steve; Simpson, Benjamin

    2008-01-01

    An extensive study of new fan exhaust nozzle technologies was performed. Three new uniform chevron nozzles were designed, based on extensive CFD analysis. Two new azimuthally varying variants were defined. All five were tested, along with two existing nozzles, on a representative model-scale, medium BPR exhaust nozzle. Substantial acoustic benefits were obtained from the uniform chevron nozzle designs, the best benefit being provided by an existing design. However, one of the azimuthally varying nozzle designs exhibited even better performance than any of the uniform chevron nozzles. In addition to the fan chevron nozzles, a new technology was demonstrated, using devices that enhance mixing when applied to an exhaust nozzle. The acoustic benefits from these devices applied to medium BPR nozzles were similar, and in some cases superior to, those obtained from conventional uniform chevron nozzles. However, none of the low noise technologies provided equivalent acoustic benefits on a model-scale high BPR exhaust nozzle, similar to current large commercial applications. New technologies must be identified to improve the acoustics of state-of-the-art high BPR jet engines.

  18. Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

    NASA Technical Reports Server (NTRS)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2015-01-01

    This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40,000) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

  19. Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

    NASA Technical Reports Server (NTRS)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2016-01-01

    This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40k (CMAPSS40k) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

  20. Engine health monitoring: An advanced system

    NASA Technical Reports Server (NTRS)

    Dyson, R. J. E.

    1981-01-01

    The advanced propulsion monitoring system is described. The system was developed in order to fulfill a growing need for effective engine health monitoring. This need is generated by military requirements for increased performance and efficiency in more complex propulsion systems, while maintaining or improving the cost to operate. This program represents a vital technological step in the advancement of the state of the art for monitoring systems in terms of reliability, flexibility, accuracy, and provision of user oriented results. It draws heavily on the technology and control theory developed for modern, complex, electronically controlled engines and utilizes engine information which is a by-product of such a system.

  1. NASA System Engineering Design Process

    NASA Technical Reports Server (NTRS)

    Roman, Jose

    2011-01-01

    This slide presentation reviews NASA's use of systems engineering for the complete life cycle of a project. Systems engineering is a methodical, disciplined approach for the design, realization, technical management, operations, and retirement of a system. Each phase of a NASA project is terminated with a Key decision point (KDP), which is supported by major reviews.

  2. Stirling engine heating system

    SciTech Connect

    Johansson, L.N.; Houtman, W.H.; Percival, W.H.

    1988-06-28

    A hot gas engine is described wherein a working gas flows back and forth in a closed path between a relatively cooler compression cylinder side of the engine and a relatively hotter expansion cylinder side of the engine and the path contains means including a heat source and a heat sink acting upon the gas in cooperation with the compression and expansion cylinders to cause the gas to execute a thermodynamic cycle wherein useful mechanical output power is developed by the engine, the improvement in the heat source which comprises a plurality of individual tubes each forming a portion of the closed path for the working gas.

  3. Automatic engine control system

    SciTech Connect

    Geary, W.C.; Mirsaiidi, M.V.; Redfern, T.; Wolfe, D.W.

    1986-01-14

    This patent describes an automatic control circuit for an internal combustion engine and clutch assembly. One component of this circuit is a timer for determining the time the engine is allowed to run and the clutch is engaged and a second period of time when the clutch is automatically disengaged. Associated with the timer is a starter means to start the engine during the first time period and a clutch actuating mechanism for engaging the clutch near the first time period initiation after the starter starts the engine. An engine shut down and clutch disengagement mechanism is also responsive to the first timer. The patent then goes on to describe a supplemental timer mechanism for determining a third and fourth period of time within the second time period such that the third period being when the engine is shut off and the fourth period being when the engine runs with clutch disengaged. The starter mechanism is responsive to the supplemental timer to start the engine at the beginning of the fourth period. A shut down means stops the engine at the beginning of the third period in response to the timer.

  4. Iterative procedures for space shuttle main engine performance models

    NASA Technical Reports Server (NTRS)

    Santi, L. Michael

    1989-01-01

    Performance models of the Space Shuttle Main Engine (SSME) contain iterative strategies for determining approximate solutions to nonlinear equations reflecting fundamental mass, energy, and pressure balances within engine flow systems. Both univariate and multivariate Newton-Raphson algorithms are employed in the current version of the engine Test Information Program (TIP). Computational efficiency and reliability of these procedures is examined. A modified trust region form of the multivariate Newton-Raphson method is implemented and shown to be superior for off nominal engine performance predictions. A heuristic form of Broyden's Rank One method is also tested and favorable results based on this algorithm are presented.

  5. Commissioning and Performance Analysis of WhisperGen Stirling Engine

    NASA Astrophysics Data System (ADS)

    Pradip, Prashant Kaliram

    Stirling engine based cogeneration systems have potential to reduce energy consumption and greenhouse gas emission, due to their high cogeneration efficiency and emission control due to steady external combustion. To date, most studies on this unit have focused on performance based on both experimentation and computer models, and lack experimental data for diversified operating ranges. This thesis starts with the commissioning of a WhisperGen Stirling engine with components and instrumentation to evaluate power and thermal performance of the system. Next, a parametric study on primary engine variables, including air, diesel, and coolant flowrate and temperature were carried out to further understand their effect on engine power and efficiency. Then, this trend was validated with the thermodynamic model developed for the energy analysis of a Stirling cycle. Finally, the energy balance of the Stirling engine was compared without and with heat recovery from the engine block and the combustion chamber exhaust.

  6. Dynamic systems-engineering process - The application of concurrent engineering

    NASA Technical Reports Server (NTRS)

    Wiskerchen, Michael J.; Pittman, R. Bruce

    1989-01-01

    A system engineering methodology is described which enables users, particulary NASA and DOD, to accommodate changing needs; incorporate emerging technologies; identify, quantify, and manage system risks; manage evolving functional requirements; track the changing environment; and reduce system life-cycle costs. The approach is a concurrent, dynamic one which starts by constructing a performance model defining the required system functions and the interrelationships. A detailed probabilistic risk assessment of the system elements and their interrelationships is performed, and quantitative analysis of the reliability and maintainability of an engineering system allows its different technical and process failure modes to be identified and their probabilities to be computed. Decision makers can choose technical solutions that maximize an objective function and minimize the probability of failure under resource constraints.

  7. Performance Engineering Technology for Scientific Component Software

    SciTech Connect

    Malony, Allen D.

    2007-05-08

    Large-scale, complex scientific applications are beginning to benefit from the use of component software design methodology and technology for software development. Integral to the success of component-based applications is the ability to achieve high-performing code solutions through the use of performance engineering tools for both intra-component and inter-component analysis and optimization. Our work on this project aimed to develop performance engineering technology for scientific component software in association with the DOE CCTTSS SciDAC project (active during the contract period) and the broader Common Component Architecture (CCA) community. Our specific implementation objectives were to extend the TAU performance system and Program Database Toolkit (PDT) to support performance instrumentation, measurement, and analysis of CCA components and frameworks, and to develop performance measurement and monitoring infrastructure that could be integrated in CCA applications. These objectives have been met in the completion of all project milestones and in the transfer of the technology into the continuing CCA activities as part of the DOE TASCS SciDAC2 effort. In addition to these achievements, over the past three years, we have been an active member of the CCA Forum, attending all meetings and serving in several working groups, such as the CCA Toolkit working group, the CQoS working group, and the Tutorial working group. We have contributed significantly to CCA tutorials since SC'04, hosted two CCA meetings, participated in the annual ACTS workshops, and were co-authors on the recent CCA journal paper [24]. There are four main areas where our project has delivered results: component performance instrumentation and measurement, component performance modeling and optimization, performance database and data mining, and online performance monitoring. This final report outlines the achievements in these areas for the entire project period. The submitted progress

  8. Systems engineering technology for networks

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The report summarizes research pursued within the Systems Engineering Design Laboratory at Virginia Polytechnic Institute and State University between May 16, 1993 and January 31, 1994. The project was proposed in cooperation with the Computational Science and Engineering Research Center at Howard University. Its purpose was to investigate emerging systems engineering tools and their applicability in analyzing the NASA Network Control Center (NCC) on the basis of metrics and measures.

  9. NASA systems engineering handbook. Draft

    NASA Technical Reports Server (NTRS)

    Shishko, Robert; Chamberlain, Robert G.; Aster, Robert; Bilardo, Vincent; Forsberg, Kevin; Hammond, Walter E.; Mooz, Harold; Polaski, Lou; Wade, Ron; Cassingham, Randy (Editor)

    1992-01-01

    This handbook is intended to provide information on systems engineering that will be useful to NASA system engineers, especially new ones. Its primary objective is to provide a generic description of systems engineering as it should be applied throughout NASA. Field Center Handbooks are encouraged to provide center-specific details of implementation. For NASA system engineers to choose to keep a copy of this handbook at their elbows, it must provide answers that cannot be easily found elsewhere. Consequently, it provides NASA-relevant perspectives and NASA-particular data. NASA management instructions (NMI's) are referenced when applicable. This handbook's secondary objective is to serve as a useful companion to all of the various courses in systems engineering that are being offered under NASA's auspices. The coverage of systems engineering is general to techniques, concepts, and generic descriptions of processes, tools, and techniques. It provides good systems engineering practices, and pitfalls to avoid. This handbook describes systems engineering as it should be applied to the development of major NASA product and producing systems.

  10. Prechamber Compression-Ignition Engine Performance

    NASA Technical Reports Server (NTRS)

    Moore, Charles S; Collins, John H , Jr

    1938-01-01

    Single-cylinder compression-ignition engine tests were made to investigate the performance characteristics of prechamber type of cylinder head. Certain fundamental variables influencing engine performance -- clearance distribution, size, shape, and direction of the passage connecting the cylinder and prechamber, shape of prechamber, cylinder clearance, compression ratio, and boosting -- were independently tested. Results of motoring and of power tests, including several typical indicator cards, are presented.

  11. Effect of propeller slipstream on the drag and performance of the engine cooling system for a general aviation twin-engine aircraft

    NASA Technical Reports Server (NTRS)

    Katz, J.; Corsiglia, V. R.; Barlow, P. R.

    1980-01-01

    The pressure recovery of incoming cooling air and the drag associated with engine cooling of a typical general aviation twin-engine aircraft was investigated experimentally. The semispan model was mounted vertically in the 40- by 80-Foot Wind Tunnel at Ames Research Center. The propeller was driven by an electric motor to provide thrust with low vibration levels for the cold-flow configuration. It was found that the propeller slipstream reduces the frontal air spillage around the blunt nacelle shape. Consequently, this slipstream effect promotes flow reattachment at the rear section of the engine nacelle and improves inlet pressure recovery. These effects are most pronounced at high angles of attack, that is, climb condition. For the cruise condition those improvements were more moderate.

  12. System safety engineering analysis handbook

    NASA Technical Reports Server (NTRS)

    Ijams, T. E.

    1972-01-01

    The basic requirements and guidelines for the preparation of System Safety Engineering Analysis are presented. The philosophy of System Safety and the various analytic methods available to the engineering profession are discussed. A text-book description of each of the methods is included.

  13. Model-Based Systems Engineering in Concurrent Engineering Centers

    NASA Technical Reports Server (NTRS)

    Iwata, Curtis; Infeld, Samantha; Bracken, Jennifer Medlin; McGuire; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman

    2015-01-01

    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a focused design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  14. Model-Based Systems Engineering in Concurrent Engineering Centers

    NASA Technical Reports Server (NTRS)

    Iwata, Curtis; Infeld, Samatha; Bracken, Jennifer Medlin; McGuire, Melissa; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman

    2015-01-01

    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a narrow design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  15. Computer simulation of engine systems

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.

    1980-01-01

    The use of computerized simulations of the steady state and transient performance of jet engines throughout the flight regime is discussed. In addition, installation effects on thrust and specific fuel consumption is accounted for as well as engine weight, dimensions and cost. The availability throughout the government and industry of analytical methods for calculating these quantities are pointed out.

  16. Analysis of Performance of Jet Engine from Characteristics of Components II : Interaction of Components as Determined from Engine Operation

    NASA Technical Reports Server (NTRS)

    Goldstein, Arthur W; Alpert, Sumner; Beede, William; Kovach, Karl

    1949-01-01

    In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.

  17. Engine systems and methods of operating an engine

    DOEpatents

    Scotto, Mark Vincent

    2015-08-25

    One embodiment of the present invention is a unique method for operating an engine. Another embodiment is a unique engine system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for engines and engine systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

  18. Intelligent Engine Systems

    NASA Technical Reports Server (NTRS)

    Xie, Ming

    2008-01-01

    A high bypass jet engine fan case represents one of the largest, heaviest single components in an engine. In addition to supporting the inlet and providing the fan flowpath, the most critical function is the containment of a failed fan blade. In this development program, a lightweight, low-cost composite containment case with diagnostic capabilities was developed, fabricated, and tested. The fan case design, containment methods, and diagnostic concepts evaluated in the initial Propulsion 21 program were improved and scaled up to a full case design.

  19. Altitude performance evaluation of J71-A-11 turbojet engine

    NASA Technical Reports Server (NTRS)

    Useller, James W; Pappas, George E

    1956-01-01

    Data were obtained with five exhaust-nozzle areas and with the variable-area exhaust nozzle interlinked with the control system at conditions simulating flight at a Mach number of 0.8 and altitudes of 35,00 and 45,000 feet. Data simulating operation at zero flight Mach number at an altitude of 15,000 feet are also included. Engine component performance data are presented in addition to the overall engine performance.

  20. Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. V - Performance of Modified Engine. V; Performance of Modified Engine

    NASA Technical Reports Server (NTRS)

    Prince, William R.; Bloomer, Harry E.

    1947-01-01

    An investigation has been conducted in the NACA Cleveland altitude wind tunnel to evaluate the performance characteristics of a modified X24C-4B turbojet engine over a range of simulated altitudes from 5000 to 45,000 feet, simulated flight Mach numbers from 0.25 to 1.07, and engine speeds from 4000 to 12,500 rpm. The engine was modified by the manufacturer to improve the velocity and temperature profiles within the engine. Performance data are graphically presented to show the effect of altitude at a flight Mach number of 0.25 and the effect of flight Mach number at an altitude of 25,000 feet. Original and modified engine performances for several specific operating conditions are compared. A complete tabulation of average pressures and temperatures throughout the engine, performance data, and lubrication and fuel-system data is presented.

  1. Robotic lunar surface operations: Engineering analysis for the design, emplacement, checkout and performance of robotic lunar surface systems

    NASA Technical Reports Server (NTRS)

    Woodcock, Gordon R.

    1990-01-01

    The assembly, emplacement, checkout, operation, and maintenance of equipment on planetary surfaces are all part of expanding human presence out into the solar system. A single point design, a reference scenario, is presented for lunar base operations. An initial base, barely more than an output, which starts from nothing but then quickly grows to sustain people and produce rocket propellant. The study blended three efforts: conceptual design of all required surface systems; assessments of contemporary developments in robotics; and quantitative analyses of machine and human tasks, delivery and work schedules, and equipment reliability. What emerged was a new, integrated understanding of hot to make a lunar base happen. The overall goal of the concept developed was to maximize return, while minimizing cost and risk. The base concept uses solar power. Its primary industry is the production of liquid oxygen for propellant, which it extracts from native lunar regolith. Production supports four lander flights per year, and shuts down during the lunar nighttime while maintenance is performed.

  2. System verification and validation: a fundamental systems engineering task

    NASA Astrophysics Data System (ADS)

    Ansorge, Wolfgang R.

    2004-09-01

    Systems Engineering (SE) is the discipline in a project management team, which transfers the user's operational needs and justifications for an Extremely Large Telescope (ELT) -or any other telescope-- into a set of validated required system performance characteristics. Subsequently transferring these validated required system performance characteris-tics into a validated system configuration, and eventually into the assembled, integrated telescope system with verified performance characteristics and provided it with "objective evidence that the particular requirements for the specified intended use are fulfilled". The latter is the ISO Standard 8402 definition for "Validation". This presentation describes the verification and validation processes of an ELT Project and outlines the key role System Engineering plays in these processes throughout all project phases. If these processes are implemented correctly into the project execution and are started at the proper time, namely at the very beginning of the project, and if all capabilities of experienced system engineers are used, the project costs and the life-cycle costs of the telescope system can be reduced between 25 and 50 %. The intention of this article is, to motivate and encourage project managers of astronomical telescopes and scientific instruments to involve the entire spectrum of Systems Engineering capabilities performed by trained and experienced SYSTEM engineers for the benefit of the project by explaining them the importance of Systems Engineering in the AIV and validation processes.

  3. Engine Data Interpretation System (EDIS)

    NASA Technical Reports Server (NTRS)

    Cost, Thomas L.; Hofmann, Martin O.

    1990-01-01

    A prototype of an expert system was developed which applies qualitative or model-based reasoning to the task of post-test analysis and diagnosis of data resulting from a rocket engine firing. A combined component-based and process theory approach is adopted as the basis for system modeling. Such an approach provides a framework for explaining both normal and deviant system behavior in terms of individual component functionality. The diagnosis function is applied to digitized sensor time-histories generated during engine firings. The generic system is applicable to any liquid rocket engine but was adapted specifically in this work to the Space Shuttle Main Engine (SSME). The system is applied to idealized data resulting from turbomachinery malfunction in the SSME.

  4. Performance Benefits for a Turboshaft Engine Using Nonlinear Engine Control Technology Investigated

    NASA Technical Reports Server (NTRS)

    Jones, Scott M.

    2004-01-01

    The potential benefits of nonlinear engine control technology applied to a General Electric T700 helicopter engine were investigated. This technology is being developed by the U.S. Navy SPAWAR Systems Center for a variety of applications. When used as a means of active stability control, nonlinear engine control technology uses sensors and small amounts of injected air to allow compressors to operate with reduced stall margin, which can improve engine pressure ratio. The focus of this study was to determine the best achievable reduction in fuel consumption for the T700 turboshaft engine. A customer deck (computer code) was provided by General Electric to calculate the T700 engine performance, and the NASA Glenn Research Center used this code to perform the analysis. The results showed a 2- to 5-percent reduction in brake specific fuel consumption (BSFC) at the three Sikorsky H-60 helicopter operating points of cruise, loiter, and hover.

  5. Enabling performance skills: Assessment in engineering education

    NASA Astrophysics Data System (ADS)

    Ferrone, Jenny Kristina

    Current reform in engineering education is part of a national trend emphasizing student learning as well as accountability in instruction. Assessing student performance to demonstrate accountability has become a necessity in academia. In newly adopted criterion proposed by the Accreditation Board for Engineering and Technology (ABET), undergraduates are expected to demonstrate proficiency in outcomes considered essential for graduating engineers. The case study was designed as a formative evaluation of freshman engineering students to assess the perceived effectiveness of performance skills in a design laboratory environment. The mixed methodology used both quantitative and qualitative approaches to assess students' performance skills and congruency among the respondents, based on individual, team, and faculty perceptions of team effectiveness in three ABET areas: Communications Skills. Design Skills, and Teamwork. The findings of the research were used to address future use of the assessment tool and process. The results of the study found statistically significant differences in perceptions of Teamwork Skills (p < .05). When groups composed of students and professors were compared, professors were less likely to perceive student's teaming skills as effective. The study indicated the need to: (1) improve non-technical performance skills, such as teamwork, among freshman engineering students; (2) incorporate feedback into the learning process; (3) strengthen the assessment process with a follow-up plan that specifically targets performance skill deficiencies, and (4) integrate the assessment instrument and practice with ongoing curriculum development. The findings generated by this study provides engineering departments engaged in assessment activity, opportunity to reflect, refine, and develop their programs as it continues. It also extends research on ABET competencies of engineering students in an under-investigated topic of factors correlated with team

  6. Systems engineering for very large systems

    NASA Technical Reports Server (NTRS)

    Lewkowicz, Paul E.

    1993-01-01

    Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

  7. Numerical Modeling of Pulse Detonation Rocket Engine Gasdynamics and Performance

    NASA Technical Reports Server (NTRS)

    Morris, C. I.

    2003-01-01

    Pulse detonation engines (PDB) have generated considerable research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional gas turbines and rocket engines. The detonative mode of combustion employed by these devices offers a theoretical thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional engines. However, the unsteady blowdown process intrinsic to all pulse detonation devices has made realistic estimates of the actual propulsive performance of PDES problematic. The recent review article by Kailasanath highlights some of the progress that has been made in comparing the available experimental measurements with analytical and numerical models.

  8. The CF6 engine performance improvement

    NASA Technical Reports Server (NTRS)

    Fasching, W. A.

    1982-01-01

    As part of the NASA-sponsored Engine Component Improvement (ECI) Program, a feasibility analysis of performance improvement and retention concepts for the CF6-6 and CF6-50 engines was conducted and seven concepts were identified for development and ground testing: new fan, new front mount, high pressure turbine aerodynamic performance improvement, high pressure turbine roundness, high pressure turbine active clearance control, low pressure turbine active clearance control, and short core exhaust nozzle. The development work and ground testing are summarized, and the major test results and an enomic analysis for each concept are presented.

  9. Performance Evaluation of the NEXT Ion Engine

    NASA Technical Reports Server (NTRS)

    Soulas, George C.; Domonkos, Matthew T.; Patterson, Michael J.

    2003-01-01

    The performance test results of three NEXT ion engines are presented. These ion engines exhibited peak specific impulse and thrust efficiency ranges of 4060 4090 s and 0.68 0.69, respectively, at the full power point of the NEXT throttle table. The performance of the ion engines satisfied all project requirements. Beam flatness parameters were significantly improved over the NSTAR ion engine, which is expected to improve accelerator grid service life. The results of engine inlet pressure and temperature measurements are also presented. Maximum main plenum, cathode, and neutralizer pressures were 12,000 Pa, 3110 Pa, and 8540 Pa, respectively, at the full power point of the NEXT throttle table. Main plenum and cathode inlet pressures required about 6 hours to increase to steady-state, while the neutralizer required only about 0.5 hour. Steady-state engine operating temperature ranges throughout the power throttling range examined were 179 303 C for the discharge chamber magnet rings and 132 213 C for the ion optics mounting ring.

  10. Systems Engineering, Quality and Testing

    NASA Technical Reports Server (NTRS)

    Shepherd, Christena C.

    2015-01-01

    AS9100 has little to say about how to apply a Quality Management System (QMS) to aerospace test programs. There is little in the quality engineering Body of Knowledge that applies to testing, unless it is nondestructive examination or some type of lab or bench testing. If one examines how the systems engineering processes are implemented throughout a test program; and how these processes can be mapped to AS9100, a number of areas for involvement of the quality professional are revealed.

  11. System Engineering Paper

    NASA Technical Reports Server (NTRS)

    Heise, James; Hull, Bethanne J.; Bauer, Jonathan; Beougher, Nathan G.; Boe, Caleb; Canahui, Ricardo; Charles, John P.; Cooper, Zachary Davis Job; DeShaw, Mark A.; Fontanella, Luan Gasparetto; Friel, Mark; Goebel, Katie; Grant, Alex Martinsdacosta; Graves, Matt; Harms, Ryan Andrew; Hill, Aren; Lsely, Kevin Lee; Jose, Sonia; Klein, Andrew; Kolstad, Lauren Wickham; Lamp, Daniel A.; Lindquist, Mariangela Martin; Lopes, Daniel da Paula; Lourens, Rob; Matthews, Christopher

    2012-01-01

    The Iowa State University team, Team LunaCY, is composed of the following sub-teams: the main student organization, the Lunabotics Club; a senior mechanical engineering design course, ME 415; a senior multidisciplinary design course, ENGR 466; and a senior design course from Wartburg College in Waverly, Iowa. Team LunaCY designed and fabricated ART-E III, Astra Robotic Tractor- Excavator the Third, for the team's third appearance in the NASA Lunabotic Mining competition. While designing ART-E III, the team had four main goals for this year's competition:to reduce the total weight of the robot, to increase the amount of regolith simulant mined, to reduce dust, and to make ART-E III autonomous. After many designs and research, a final robot design was chosen that obtained all four goals of Team LunaCY. A few changes Team LunaCY made this year was to go to the electrical, computer, and software engineering club fest at Iowa State University to recruit engineering students to accomplish the task of making ART-E III autonomous. Team LunaCY chose to use LabView to program the robot and various sensors were installed to measure the distance between the robot and the surroundings to allow ART-E III to maneuver autonomously. Team LunaCY also built a testing arena to test prototypes and ART-E III in. To best replicate the competition arena at the Kennedy Space Center, a regolith simulant was made from sand, QuickCrete, and fly ash to cover the floor of the arena. Team LunaCY also installed fans to allow ventilation in the arena and used proper safety attire when working in the arena . With the additional practice in the testing arena and innovative robot design, Team LunaCY expects to make a strong appearance at the 2012 NASA Lunabotic Mining Competition. .

  12. Engineering of complex systems: The impact of systems engineering at NASA

    NASA Astrophysics Data System (ADS)

    Kludze, Ave-Klutse Kodzo Paaku

    The "true" impact or value of systems engineering to an organization unfortunately appears not to have been well-studied and understood. The principles of systems engineering are highly encouraged by NASA at all levels, and most practitioners, both internal and external to NASA, intuitively "believe" it adds some value to the development of complex systems by producing them faster, better and cheaper. This research, in trying to fill a gap that exists in the systems engineering literature, analyzes data collected within NASA and other sources external to NASA (INCOSE) for comparisons. Analyses involving a number of case studies performed on selected NASA projects are presented to draw attention to the impact systems engineering had or could have had on these projects. This research clearly shows that systems engineering does add value to projects within and outside NASA. The research results further demonstrate that systems engineering has been beneficial not only to NASA but also to organizations within which INCOSE members work. It was determined, however, that systems engineering does not operate in a vacuum and may not always guarantee success through mere application. During this research, it was discovered that the lack of or inadequate application of systems engineering in the development of complex systems may result in cost overruns, poor technical performance, project delays, and in some cases unmitigated risk with disastrous consequences including the loss of life and property. How much is saved (in terms of cost, schedule) or improved (in terms of technical performance) as a result of its implementation may never be known precisely, but by indirectly measuring its value or impact on a project, percentages of project budget spent on systems engineering activities and any schedule reductions or performance enhancements realized could be determined. According to this research, systems engineering is not a waste of time and resources; in most cases, it is

  13. Factors affecting performance of engineered barriers

    SciTech Connect

    Blink, J. A., LLNL

    1998-03-01

    For the Yucca Mountain Viability Assessment (VA), a reference design was tentatively selected` In September 1997, and a series of model abstractions are being prepared for the performance assessment (PA) of that design. To determine the sensitivity of peak dose rate at the accessible environment to engineered components, several design options were subjected to the PA models available late in FY97.

  14. FACTORS AFFECTING PERFORMANCE OF ENGINEERED BARRIERS

    SciTech Connect

    Blink, J. A.; Bailey, T. W.; Doering, W.; Lee, J. K.; Mccoy, J. K.; McKenzie, D. G.; Sevougian, D.; Vallikat, V.

    1998-03-01

    For the Yucca Mountain Viability Assessment (VA), a reference design was tentatively selected in September 1997, and a series of model abstractions are being prepared for the performance assessment (PA) of that design. To determine the sensitivity of peak dose rate at the accessible environment to engineered components, several design options were subjected to the PA models available late in FY97.

  15. Gasoline Engine Mechanics. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives presented in this curriculum guide for an intermediate gasoline engine mechanics course at the secondary level. (For the beginning course guide see CE 010 947.) The materials were developed for a two-semester (2 hour…

  16. Marine Engine Mechanics. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are presented for each of six terminal objectives for a two-semester course (2 hours daily) which provides training in the terminology, construction, and function of both two- and four-cycle fuel-air mixture internal combustion engines with emphasis on outboard marine…

  17. Gasoline Engine Mechanics. Performance Objectives. Basic Course.

    ERIC Educational Resources Information Center

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are listed for each of five terminal objectives presented in this curriculum guide for a basic gasoline engine mechanics course at the secondary level. (For the intermediate course guide see CE 010 946.) The materials were developed for a two semester (2 hours daily)…

  18. A scalable engineering approach to improve performance of a miniaturized optical detection system for in vitro point-of-care testing

    NASA Astrophysics Data System (ADS)

    Robbins, Hannah; Hu, Sijung; Liu, Changqing

    2015-03-01

    The demand for rapid screening technologies, to be used outside of a traditional healthcare setting, has been vastly expanding. This is requiring a new engineering platform for faster and cost effective techniques to be easily adopted through forward-thinking manufacturing procedures, i.e., advanced miniaturisation and heterogeneous integration of high performance microfluidics based point-of-care testing (POCT) systems. Although there has been a considerable amount of research into POCT systems, there exist tremendous challenges and bottlenecks in the design and manufacturing in order to reach a clinical acceptability of sensitivity and selectivity, as well as smart microsystems for healthcare. The project aims to research how to enable scalable production of such complex systems through 1) advanced miniaturisation of a physical layout and opto-electronic component allocation through an optimal design; and 2) heterogeneous integration of multiplexed fluorescence detection (MFD) for in vitro POCT. Verification is being arranged through experimental testing with a series of dilutions of commonly used fluorescence dye, i.e. Cy5. Iterative procedures will be engaged until satisfaction of the detection limit, of Cy5 dye, 1.209x10-10 M. The research creates a new avenue of rapid screening POCT manufacturing solutions with a particular view on high performance and multifunctional detection systems not only in POCT, but also life sciences and environmental applications.

  19. Cassini Main Engine Assembly Cover Flight Management and Performance

    NASA Technical Reports Server (NTRS)

    Somawardhana, Ruwan P.; Millard, Jerry M.

    2010-01-01

    The Cassini spacecraft has performed its four year Prime Mission at Saturn and is currently in orbit at Saturn performing a two year extended mission. 12Its main engine nozzles are susceptible to impact damage from micrometeoroids and on-orbit dust. The spacecraft has an articulating device known as the Main Engine Assembly (MEA) cover which can close and shield the main engines from these threats. The cover opens to allow for main engine burns that are necessary to maintain the trajectory. Periodically updated analyses of potential on-orbit dust hazard threats have resulted in the need to continue to use the MEA cover beyond its intended use and beyond its design life. This paper provides a detailed Systems-level overview of the flight management of the MEA cover device and its flight performance to date.

  20. Rotary engine performance computer program (RCEMAP and RCEMAPPC): User's guide

    NASA Technical Reports Server (NTRS)

    Bartrand, Timothy A.; Willis, Edward A.

    1993-01-01

    This report is a user's guide for a computer code that simulates the performance of several rotary combustion engine configurations. It is intended to assist prospective users in getting started with RCEMAP and/or RCEMAPPC. RCEMAP (Rotary Combustion Engine performance MAP generating code) is the mainframe version, while RCEMAPPC is a simplified subset designed for the personal computer, or PC, environment. Both versions are based on an open, zero-dimensional combustion system model for the prediction of instantaneous pressures, temperature, chemical composition and other in-chamber thermodynamic properties. Both versions predict overall engine performance and thermal characteristics, including bmep, bsfc, exhaust gas temperature, average material temperatures, and turbocharger operating conditions. Required inputs include engine geometry, materials, constants for use in the combustion heat release model, and turbomachinery maps. Illustrative examples and sample input files for both versions are included.

  1. Adaptive Systems Engineering: A Medical Paradigm for Practicing Systems Engineering

    SciTech Connect

    R. Douglas Hamelin; Ron D. Klingler; Christopher Dieckmann

    2011-06-01

    From its inception in the defense and aerospace industries, SE has applied holistic, interdisciplinary tools and work-process to improve the design and management of 'large, complex engineering projects.' The traditional scope of engineering in general embraces the design, development, production, and operation of physical systems, and SE, as originally conceived, falls within that scope. While this 'traditional' view has expanded over the years to embrace wider, more holistic applications, much of the literature and training currently available is still directed almost entirely at addressing the large, complex, NASA and defense-sized systems wherein the 'ideal' practice of SE provides the cradle-to-grave foundation for system development and deployment. Under such scenarios, systems engineers are viewed as an integral part of the system and project life-cycle from conception to decommissioning. In far less 'ideal' applications, SE principles are equally applicable to a growing number of complex systems and projects that need to be 'rescued' from overwhelming challenges that threaten imminent failure. The medical profession provides a unique analogy for this latter concept and offers a useful paradigm for tailoring our 'practice' of SE to address the unexpected dynamics of applying SE in the real world. In short, we can be much more effective as systems engineers as we change some of the paradigms under which we teach and 'practice' SE.

  2. Human Engineering Modeling and Performance Lab Study Project

    NASA Technical Reports Server (NTRS)

    Oliva-Buisson, Yvette J.

    2014-01-01

    The HEMAP (Human Engineering Modeling and Performance) Lab is a joint effort between the Industrial and Human Engineering group and the KAVE (Kennedy Advanced Visualiations Environment) group. The lab consists of sixteen camera system that is used to capture human motions and operational tasks, through te use of a Velcro suit equipped with sensors, and then simulate these tasks in an ergonomic software package know as Jac, The Jack software is able to identify the potential risk hazards.

  3. Engine NOx reduction system

    SciTech Connect

    Berriman, L.P.; Zabsky, J.M.; Davis, J.W.; Hylton, W.H.

    1993-07-06

    Apparatus for use with an engine having a power-generating portion that burns a hydrocarbon fuel and air and produces hot exhaust gases is described, having a catalytic converter device that includes a catalyst for enhancing reactions of components of said exhaust gases, and having a conduit that couples said power-generating portion to said catalytic converter device, for reducing pollution in the exhaust, wherein said power-generating portion comprises a plurality of cylinders in which said fuel and air are burned, a mechanism for applying fuel and air to said cylinders, and a plurality of exhaust valves through which burned fuel and air is exhausted and which are connected to said upstream end of said conduit, said conduit including a manifold which is connected to a plurality of said exhaust valves and a downstream conduit portion which connects said manifold to said catalytic converter device, comprising: a device coupled to said conduit, which stores ammonia and injects it into said conduit at a location where the exhaust gases have a substantially maximum temperature, but which is devoid of open flames, to mix with said hot exhaust gases and pass with them along said conduit and then through said catalyst, said location being closer to said power-generating portion than to said catalytic converter and lying in said manifold.

  4. Optimized tuner selection for engine performance estimation

    NASA Technical Reports Server (NTRS)

    Simon, Donald L. (Inventor); Garg, Sanjay (Inventor)

    2013-01-01

    A methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multi-variable iterative search routine which seeks to minimize the theoretical mean-squared estimation error. Theoretical Kalman filter estimation error bias and variance values are derived at steady-state operating conditions, and the tuner selection routine is applied to minimize these values. The new methodology yields an improvement in on-line engine performance estimation accuracy.

  5. The cost of performance - A comparison of the space transportation main engine and the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Barisa, B. B.; Flinchbaugh, G. D.; Zachary, A. T.

    1989-01-01

    This paper compares the cost of the Space Shuttle Main Engine (SSME) and the Space Transportation Main Engine (STME) proposed by the Advanced Launch System Program. A brief description of the SSME and STME engines is presented, followed by a comparison of these engines that illustrates the impact of focusing on acceptable performance at minimum cost (as for the STME) or on maximum performance (as for the SSME). Several examples of cost reduction methods are presented.

  6. Industrial and Systems Engineering Applications in NASA

    NASA Technical Reports Server (NTRS)

    Shivers, Charles H.

    2006-01-01

    A viewgraph presentation on the many applications of Industrial and Systems Engineering used for safe NASA missions is shown. The topics include: 1) NASA Information; 2) Industrial Engineering; 3) Systems Engineering; and 4) Major NASA Programs.

  7. Temperature measurement. [liquid monopropellant rocket engine performance tests

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The design, installation, checkout, calibration, and operation of a temperature measuring system to be used during tests of a liquid monopropellant rocket engine are discussed. Appendixes include: (1) temperature measurement system elemental uncertainties, and (2) tables and equations for use with thermocouples and resistance thermometers. Design guidelines are given for the critical components of each portion of the system to provide an optimum temperature measurement system which meets the performance criteria specified.

  8. Energy Efficient Engine: Combustor component performance program

    NASA Technical Reports Server (NTRS)

    Dubiel, D. J.

    1986-01-01

    The results of the Combustor Component Performance analysis as developed under the Energy Efficient Engine (EEE) program are presented. This study was conducted to demonstrate the aerothermal and environmental goals established for the EEE program and to identify areas where refinements might be made to meet future combustor requirements. In this study, a full annular combustor test rig was used to establish emission levels and combustor performance for comparison with those indicated by the supporting technology program. In addition, a combustor sector test rig was employed to examine differences in emissions and liner temperatures obtained during the full annular performance and supporting technology tests.

  9. Final Report: Performance Engineering Research Institute

    SciTech Connect

    Mellor-Crummey, John

    2014-10-27

    This document is a final report about the work performed for cooperative agreement DE-FC02-06ER25764, the Rice University effort of Performance Engineering Research Institute (PERI). PERI was an Enabling Technologies Institute of the Scientific Discovery through Advanced Computing (SciDAC-2) program supported by the Department of Energy's Office of Science Advanced Scientific Computing Research (ASCR) program. The PERI effort at Rice University focused on (1) research and development of tools for measurement and analysis of application program performance, and (2) engagement with SciDAC-2 application teams.

  10. Engineered Barrier System: Physical and Chemical Environment

    SciTech Connect

    P. Dixon

    2004-04-26

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  11. Computer systems and software engineering

    NASA Technical Reports Server (NTRS)

    Mckay, Charles W.

    1988-01-01

    The High Technologies Laboratory (HTL) was established in the fall of 1982 at the University of Houston Clear Lake. Research conducted at the High Tech Lab is focused upon computer systems and software engineering. There is a strong emphasis on the interrelationship of these areas of technology and the United States' space program. In Jan. of 1987, NASA Headquarters announced the formation of its first research center dedicated to software engineering. Operated by the High Tech Lab, the Software Engineering Research Center (SERC) was formed at the University of Houston Clear Lake. The High Tech Lab/Software Engineering Research Center promotes cooperative research among government, industry, and academia to advance the edge-of-knowledge and the state-of-the-practice in key topics of computer systems and software engineering which are critical to NASA. The center also recommends appropriate actions, guidelines, standards, and policies to NASA in matters pertinent to the center's research. Results of the research conducted at the High Tech Lab/Software Engineering Research Center have given direction to many decisions made by NASA concerning the Space Station Program.

  12. Diesel engine fuel systems

    SciTech Connect

    Not Available

    1994-01-01

    The film shows the basic structure of diesel systems, including the parts and operation of injectors and fuel pumps. It discusses Bosch, General Motors, and Excello Equipment. This title has been declared obsolete for use within the sponsoring agency, but may have content value for educational use.

  13. Diesel engine fuel systems

    SciTech Connect

    1994-12-31

    The film shows the basic structure of diesel systems, including the parts and operation of injectors and fuel pumps. It discusses Bosch, General Motors, and Excello Equipment. This title has been declared obsolete for use within the sponsoring agency, but may have content value for educational use.

  14. Diesel engine catalytic combustor system. [aircraft engines

    NASA Technical Reports Server (NTRS)

    Ream, L. W. (Inventor)

    1984-01-01

    A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section.

  15. Security systems engineering overview

    NASA Astrophysics Data System (ADS)

    Steele, Basil J.

    1997-01-01

    Crime prevention is on the minds of most people today. The concern for public safety and the theft of valuable assets are being discussed at all levels of government and throughout the public sector. There is a growing demand for security systems that can adequately safeguard people and valuable assets against the sophistication of those criminals or adversaries who pose a threat. The crime in this country has been estimated at 70 billion dollars in direct costs and up to 300 billion dollars in indirect costs. Health insurance fraud alone is estimated to cost American businesses 100 billion dollars. Theft, warranty fraud, and counterfeiting of computer hardware totaled 3 billion dollars in 1994. A threat analysis is a prerequisite to any security system design to assess the vulnerabilities with respect to the anticipated threat. Having established a comprehensive definition of the threat, crime prevention, detection, and threat assessment technologies can be used to address these criminal activities. This talk will outline the process used to design a security system regardless of the level of security. This methodology has been applied to many applications including: government high security facilities; residential and commercial intrusion detection and assessment; anti-counterfeiting/fraud detection technologies; industrial espionage detection and prevention; security barrier technology.

  16. Security systems engineering overview

    SciTech Connect

    Steele, B.J.

    1996-12-31

    Crime prevention is on the minds of most people today. The concern for public safety and the theft of valuable assets are being discussed at all levels of government and throughout the public sector. There is a growing demand for security systems that can adequately safeguard people and valuable assets against the sophistication of those criminals or adversaries who pose a threat. The crime in this country has been estimated at $70 billion in direct costs and up to $300 billion in indirect costs. Health insurance fraud alone is estimated to cost American businesses $100 billion. Theft, warranty fraud, and counterfeiting of computer hardware totaled $3 billion in 1994. A threat analysis is a prerequisite to any security system design to assess the vulnerabilities with respect to the anticipated threat. Having established a comprehensive definition of the threat, crime prevention, detection, and threat assessment technologies can be used to address these criminal activities. This talk will outline the process used to design a security system regardless of the level of security. This methodology has been applied to many applications including: government high security facilities; residential and commercial intrusion detection and assessment; anti-counterfeiting/fraud detection technologies (counterfeit currency, cellular phone billing, credit card fraud, health care fraud, passport, green cards, and questionable documents); industrial espionage detection and prevention (intellectual property, computer chips, etc.); and security barrier technology (creation of delay such as gates, vaults, etc.).

  17. Generative engineering databases - Toward expert systems

    NASA Technical Reports Server (NTRS)

    Rasdorf, W. J.; Salley, G. C.

    1985-01-01

    Engineering data management, incorporating concepts of optimization with data representation, is receiving increasing attention as the amount and complexity of information necessary for performing engineering operations increases and the need to coordinate its representation and use increases. Research in this area promises advantages for a wide variety of engineering applications, particularly those which seek to use data in innovative ways in the engineering process. This paper presents a framework for a comprehensive, relational database management system that combines a knowledge base of design constraints with a database of engineering data items in order to achieve a 'generative database' - one which automatically generates new engineering design data according to the design constraints stored in the knowledge base. The representation requires a database that is able to store all of the data normally associated with engineering design and to accurately represent the interactions between constraints and the stored data while guaranteeing its integrity. The representation also requires a knowledge base that is able to store all the constraints imposed upon the engineering design process.

  18. CAESY - COMPUTER AIDED ENGINEERING SYSTEM

    NASA Technical Reports Server (NTRS)

    Wette, M. R.

    1994-01-01

    Many developers of software and algorithms for control system design have recognized that current tools have limits in both flexibility and efficiency. Many forces drive the development of new tools including the desire to make complex system modeling design and analysis easier and the need for quicker turnaround time in analysis and design. Other considerations include the desire to make use of advanced computer architectures to help in control system design, adopt new methodologies in control, and integrate design processes (e.g., structure, control, optics). CAESY was developed to provide a means to evaluate methods for dealing with user needs in computer-aided control system design. It is an interpreter for performing engineering calculations and incorporates features of both Ada and MATLAB. It is designed to be reasonably flexible and powerful. CAESY includes internally defined functions and procedures, as well as user defined ones. Support for matrix calculations is provided in the same manner as MATLAB. However, the development of CAESY is a research project, and while it provides some features which are not found in commercially sold tools, it does not exhibit the robustness that many commercially developed tools provide. CAESY is written in C-language for use on Sun4 series computers running SunOS 4.1.1 and later. The program is designed to optionally use the LAPACK math library. The LAPACK math routines are available through anonymous ftp from research.att.com. CAESY requires 4Mb of RAM for execution. The standard distribution medium is a .25 inch streaming magnetic tape cartridge (QIC-24) in UNIX tar format. CAESY was developed in 1993 and is a copyrighted work with all copyright vested in NASA.

  19. Performance characteristics of the Lysholm engine

    SciTech Connect

    Berger, R.E.

    1980-01-01

    The performance of a 5 in. diameter rotor Lysholm engine prototype running on simulated geothermal flows from 16 to 100% quality is described. Staging was performed with conventional Westinghouse 25 kW steam turbines demonstrating that such a process is feasible. Maximum efficiency and power noted were 37.2% and 26.3 kW respectively, but inhibiting factors were discovered which, upon correction, should allow efficiencies around 50% and powers up to 35 kW. Larger engines with minor modifications should get better efficiencies. Data was taken for inlet pressures of 75 to 120 psia and speeds of 3000 to 9000 rpm's. Further testing under similar conditions is planned.

  20. Hubble Space Telescope systems engineering

    NASA Technical Reports Server (NTRS)

    Wojtalik, F. S.

    1988-01-01

    The role of systems engineering in the Hubble Space Telescope (HST) development program at NASA Marshall is reviewed. The scientific objectives and overall characteristics of the HST are recalled, and particular attention is given to the early identification and correction of problems in the optical system, the pointing-control system (maneuvering and fine guidance), the rate-gyro assembly, reaction-wheel isolation, the battery reconditioning circuit, and optical cleanliness.

  1. Engineering intelligent tutoring systems

    NASA Technical Reports Server (NTRS)

    Warren, Kimberly C.; Goodman, Bradley A.

    1993-01-01

    We have defined an object-oriented software architecture for Intelligent Tutoring Systems (ITS's) to facilitate the rapid development, testing, and fielding of ITS's. This software architecture partitions the functionality of the ITS into a collection of software components with well-defined interfaces and execution concept. The architecture was designed to isolate advanced technology components, partition domain dependencies, take advantage of the increased availability of commercial software packages, and reduce the risks involved in acquiring ITS's. A key component of the architecture, the Executive, is a publish and subscribe message handling component that coordinates all communication between ITS components.

  2. 1-D Numerical Analysis of RBCC Engine Performance

    NASA Technical Reports Server (NTRS)

    Han, Samuel S.

    1998-01-01

    An RBCC engine combines air breathing and rocket engines into a single engine to increase the specific impulse over an entire flight trajectory. Considerable research pertaining to RBCC propulsion was performed during the 1960's and these engines were revisited recently as a candidate propulsion system for either a single-stage-to-orbit (SSTO) or two-stage-to-orbit (TSTO) launch vehicle. There are a variety of RBCC configurations that had been evaluated and new designs are currently under development. However, the basic configuration of all RBCC systems is built around the ejector scramjet engine originally developed for the hypersonic airplane. In this configuration, a rocket engine plays as an ejector in the air-augmented initial acceleration mode, as a fuel injector in scramjet mode and the rocket in all rocket mode for orbital insertion. Computational fluid dynamics (CFD) is a useful tool for the analysis of complex transport processes in various components in RBCC propulsion systems. The objective of the present research was to develop a transient 1-D numerical model that could be used to predict flow behavior throughout a generic RBCC engine following a flight path.

  3. System Engineering of Photonic Systems for Space Application

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Pryor, Jonathan E.

    2014-01-01

    The application of photonics in space systems requires tight integration with the spacecraft systems to ensure accurate operation. This requires some detailed and specific system engineering to properly incorporate the photonics into the spacecraft architecture and to guide the spacecraft architecture in supporting the photonics devices. Recent research in product focused, elegant system engineering has led to a system approach which provides a robust approach to this integration. Focusing on the mission application and the integration of the spacecraft system physics incorporation of the photonics can be efficiently and effectively accomplished. This requires a clear understanding of the driving physics properties of the photonics device to ensure proper integration with no unintended consequences. The driving physics considerations in terms of optical performance will be identified for their use in system integration. Keywords: System Engineering, Optical Transfer Function, Optical Physics, Photonics, Image Jitter, Launch Vehicle, System Integration, Organizational Interaction

  4. SSME engine system integration of the alternate turbopump program

    NASA Technical Reports Server (NTRS)

    Sander, E. J.; Leahy, J. C.

    1993-01-01

    The effect of the engine level integration of the alternate High Pressure Oxidizer Turbopump (HPOTP) on the performance of the Space Shuttle Main Engine (SSME) is examined with reference to the results of the current engine system ground test data analysis. In particular, attention is given to the observed steady state and transient mainstage engine system effects with respect to various engine hardware combinations. It is concluded that none of the engine system concerns eliminate the turbomump from consideration as a permanent addition to the flight program pending certification.

  5. Heat engine development for solar thermal power systems

    NASA Technical Reports Server (NTRS)

    Pham, H. Q.; Jaffe, L. D.

    1981-01-01

    The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

  6. SSME engine system integration of the alternate turbopump program

    NASA Astrophysics Data System (ADS)

    Sander, E. J.; Leahy, J. C.

    1993-06-01

    The effect of the engine level integration of the alternate High Pressure Oxidizer Turbopump (HPOTP) on the performance of the Space Shuttle Main Engine (SSME) is examined with reference to the results of the current engine system ground test data analysis. In particular, attention is given to the observed steady state and transient mainstage engine system effects with respect to various engine hardware combinations. It is concluded that none of the engine system concerns eliminate the turbomump from consideration as a permanent addition to the flight program pending certification.

  7. Jet engine air intake system

    NASA Technical Reports Server (NTRS)

    Sorensen, N. E.; Latham, E. A. (Inventor)

    1977-01-01

    An axisymmetric air intake system for a jet aircraft engine comprising a fixed cowl extending outwardly from the face of the engine, a centerbody coaxially disposed within the cowl, and an actuator for axially displacing the centerbody within the cowl was developed. The cowl and centerbody define a main airflow passageway therebetween, the configuration of which is changed by displacement of the centerbody. The centerbody includes a forwardly-located closeable air inlet which communicates with a centerbody auxiliary airflow passageway to provide auxiliary airflow to the engine. In one embodiment, a system for opening and closing the centerbody air inlet is provided by a dual-member centerbody, the forward member of which may be displaced axially with respect to the aft member.

  8. Computer Jet-Engine-Monitoring System

    NASA Technical Reports Server (NTRS)

    Disbrow, James D.; Duke, Eugene L.; Ray, Ronald J.

    1992-01-01

    "Intelligent Computer Assistant for Engine Monitoring" (ICAEM), computer-based monitoring system intended to distill and display data on conditions of operation of two turbofan engines of F-18, is in preliminary state of development. System reduces burden on propulsion engineer by providing single display of summary information on statuses of engines and alerting engineer to anomalous conditions. Effective use of prior engine-monitoring system requires continuous attention to multiple displays.

  9. Performance Charts for the Turbojet Engine

    NASA Technical Reports Server (NTRS)

    Pinkel, Benjamin; Karp, Irving M.

    1947-01-01

    Charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet engine for any given set of operating conditions and component efficiencies. The effects of the pressure losses in the inlet duct and combustion chamber, the variation in the physical properties of the gas as it passes through the cycle, and the change in mass flow by the addition of fuel are included. The principle performance charts show the effects of the primary variables and correction charts provide the effects of the secondary variables.

  10. An engineered cover system for mine tailings using a hardpan layer: a solidification/stabilization method for layer and field performance evaluation.

    PubMed

    Ahn, Joo Sung; Song, Hocheol; Yim, Gil-Jae; Ji, Sang Woo; Kim, Jae-Gon

    2011-12-15

    A cover system for mine tailings with a solidified layer (called an engineered hardpan) was developed in this study to reduce water infiltration, acid generation and sulfide oxidation. Hydrated lime and waterglass were used to produce calcium silicate, which can serve as a binder when constructing a hardpan layer. The compressive strength of each solidified/stabilized material was found to be sufficient in the lab, and the amounts of heavy metals were significantly reduced in chemical leaching tests. Various characteristics of tailings may affect the layer's mechanical strength early on, but a long curing period is capable of compensating for these effects. Heavy metals were stabilized as carbonate-bound phases and sulfide minerals were surrounded by calcium silicate matrix, thereby preventing further reaction. To evaluate the field performance of the system, a hardpan layer was installed on top of tailings on a pilot scale. Leachate with high salt content was generated in the tailings layer in the early stages of monitoring, but after approximately 6 months, the objective was achieved as the hardpan layer gradually stabilized. Notably, during the heavy rainfall season of the later monitoring stage, water infiltration was continuously prevented by the system. PMID:21974852

  11. 2.0 AEDL Systems Engineering

    NASA Technical Reports Server (NTRS)

    Graves, Claude

    2005-01-01

    Some engineering topics: Some Initial Thoughts. Capability Description. Capability State-of-the-Art. Capability Requirements. Systems Engineering. Capability Roadmap. Capability Maturity. Candidate Technologies. Metrics.

  12. Systems engineering implementation plan for the liquid effluents services program

    SciTech Connect

    Lowe, S.S.

    1995-01-01

    A graded approach is being taken by the Liquid Effluents Services Program in implementing systems engineering because of the advanced state of the program. The approach is cost-effective and takes credit for related work already completed, yet retains the benefits of systems engineering. This plan describes how the Liquid Effluents Services Program will implement systems engineering so there is a common understanding. Systems engineering work to be performed and the products of that work are identified. The relation to the current planning process and integration with the sitewide systems engineering effort is described.

  13. Performance Engineering: Understanding and Improving thePerformance of Large-Scale Codes

    SciTech Connect

    Bailey, David H.; Lucas, Robert; Hovland, Paul; Norris, Boyana; Yelick, Kathy; Gunter, Dan; de Supinski, Bronis; Quinlan, Dan; Worley,Pat; Vetter, Jeff; Roth, Phil; Mellor-Crummey, John; Snavely, Allan; Hollingsworth, Jeff; Reed, Dan; Fowler, Rob; Zhang, Ying; Hall, Mary; Chame, Jacque; Dongarra, Jack; Moore, Shirley

    2007-10-01

    Achieving good performance on high-end computing systems is growing ever more challenging due to enormous scale, increasing architectural complexity, and increasing application complexity. To address these challenges in DOE's SciDAC-2 program, the Performance Engineering Research Institute (PERI) has embarked on an ambitious research plan encompassing performance modeling and prediction, automatic performance optimization and performance engineering of high profile applications. The principal new component is a research activity in automatic tuning software, which is spurred by the strong user preference for automatic tools.

  14. Building America Systems Engineering Approach

    SciTech Connect

    2011-12-15

    The Building America Research Teams use a systems engineering approach to achieve higher quality and energy savings in homes. Using these techniques, the energy consumption of new houses can be reduced by 40% or more with little or no impact on the cost of ownership.

  15. Engineer's Refractive Effects Prediction System (EREPS)

    NASA Astrophysics Data System (ADS)

    Hitney, Herbert V.

    1989-09-01

    In recent years, electromagnetic tactical decision aids were developed to assess environmental effects on the performance of operational systems such as shipboard radars. In general, these systems have performed well and are now routinely used by operational forces to optimize their use of sensors and deployment of forces. In many cases, the existing tactical decision aid software was taken and used to assess the performance of proposed new sensors. Since the original software was not designed for this purpose, many deficiencies in such a use were soon identified. For example, most engineers prefer to graphically compare performance results as a single design parameter, such as radar pulse length, is varied over a range of possible values. Also, in designing a new system, one is usually more interested in the long-term statistical performance than in single-event performance that the tactical decision aids are normally designed to assess. The Engineer's Refractive Effects Prediction System (EREPS) is a recent development effort tailored to engineering uses and based on the propagation models of the Integrated Refractive Effects Prediction System (IREPS). EREPS is hosted on IBM PC computers for maximum availability to the engineering community, and was developed using interactive graphics displays for optimum comparison studies. The models are designed in such a way as to give results within a few seconds to allow multiple design trade-off studies to be easily performed. EREPS Revision 1.00 was distributed to interested users in the summer of 1988 and is currently being revised for a summer 1989 distribution. Existing and planned capabilities will be presented along with some examples of applications.

  16. Optimization in the systems engineering process

    NASA Technical Reports Server (NTRS)

    Lemmerman, Loren A.

    1993-01-01

    The essential elements of the design process consist of the mission definition phase that provides the system requirements, the conceptual design, the preliminary design and finally the detailed design. Mission definition is performed largely by operations analysts in conjunction with the customer. The result of their study is handed off to the systems engineers for documentation as the systems requirements. The document that provides these requirements is the basis for the further design work of the design engineers at the Lockheed-Georgia Company. The design phase actually begins with conceptual design, which is generally conducted by a small group of engineers using multidisciplinary design programs. Because of the complexity of the design problem, the analyses are relatively simple and generally dependent on parametric analyses of the configuration. The result of this phase is a baseline configuration from which preliminary design may be initiated.

  17. Hydrogen engine performance analysis project. First quarterly report, March 1980

    SciTech Connect

    Adt, Jr, R R; Swain, M R; Pappas, J M

    1980-01-01

    Progress in a program aimed at obtaining operational and performance data on a prototype pre intake valve closing fuel ingestion (PreIVC) hydrogen-fueled automotive engine is reported. Information is included on the construction and testing of an unthrottled hydrogen delivery system and on flashback during starting. It was determined that the flashback was caused by runaway surface ignition. (LCL)

  18. High-performance computing in structural mechanics and engineering

    SciTech Connect

    Adeli, H.; Kamat, M.P.; Kulkarni, G.; Vanluchene, R.D. Georgia Inst. of Technology, Atlanta Montana State Univ., Bozeman )

    1993-07-01

    Recent advances in computer hardware and software have made multiprocessing a viable and attractive technology. This paper reviews high-performance computing methods in structural mechanics and engineering through the use of a new generation of multiprocessor computers. The paper presents an overview of vector pipelining, performance metrics for parallel and vector computers, programming languages, and general programming considerations. Recent developments in the application of concurrent processing techniques to the solution of structural mechanics and engineering problems are reviewed, with special emphasis on linear structural analysis, nonlinear structural analysis, transient structural analysis, dynamics of multibody flexible systems, and structural optimization. 64 refs.

  19. Engineered containment and control systems: nurturing nature.

    PubMed

    Clarke, James H; MacDonell, Margaret M; Smith, Ellen D; Dunn, R Jeffrey; Waugh, W Jody

    2004-06-01

    The development of engineered containment and control systems for contaminated sites must consider the environmental setting of each site. The behaviors of both contaminated materials and engineered systems are affected by environmental conditions that will continue to evolve over time as a result of such natural processes as climate change, ecological succession, pedogenesis, and landform changes. Understanding these processes is crucial to designing, implementing, and maintaining effective systems for sustained health and environmental protection. Traditional engineered systems such as landfill liners and caps are designed to resist natural processes rather than working with them. These systems cannot be expected to provide long-term isolation without continued maintenance. In some cases, full-scale replacement and remediation may be required within 50 years, at an effort and cost much higher than for the original cleanup. Approaches are being developed to define smarter containment and control systems for stewardship sites, considering lessons learned from implementing prescriptive waste disposal regulations enacted since the 1970s. These approaches more effectively involve integrating natural and engineered systems; enhancing sensors and predictive tools for evaluating performance; and incorporating information on failure events, including precursors and consequences, into system design and maintenance. An important feature is using natural analogs to predict environmental conditions and system responses over the long term, to accommodate environmental change in the design process, and, as possible, to engineer containment systems that mimic favorable natural systems. The key emphasis is harmony with the environment, so systems will work with and rely on natural processes rather than resisting them. Implementing these new integrated systems will reduce current requirements for active management, which are resource-intensive and expensive. PMID:15209944

  20. Engineered containment and control systems : nurturing nature.

    SciTech Connect

    MacDonell, M.; Clarke, J.; Smith, E.; Dunn, J.; Waugh, J.; Environmental Assessment; Vanderbilt Univ.; ORNL; Kleinfelder; U.S. Department of Energy Grand Junction Office

    2004-06-01

    The development of engineered containment and control systems for contaminated sites must consider the environmental setting of each site. The behaviors of both contaminated materials and engineered systems are affected by environmental conditions that will continue to evolve over time as a result of such natural processes as climate change, ecological succession, pedogenesis, and landform changes. Understanding these processes is crucial to designing, implementing, and maintaining effective systems for sustained health and environmental protection. Traditional engineered systems such as landfill liners and caps are designed to resist natural processes rather than working with them. These systems cannot be expected to provide long-term isolation without continued maintenance. In some cases, full-scale replacement and remediation may be required within 50 years, at an effort and cost much higher than for the original cleanup. Approaches are being developed to define smarter containment and control systems for stewardship sites, considering lessons learned from implementing prescriptive waste disposal regulations enacted since the 1970s. These approaches more effectively involve integrating natural and engineered systems; enhancing sensors and predictive tools for evaluating performance; and incorporating information on failure events, including precursors and consequences, into system design and maintenance. An important feature is using natural analogs to predict environmental conditions and system responses over the long term, to accommodate environmental change in the design process, and, as possible, to engineer containment systems that mimic favorable natural systems. The key emphasis is harmony with the environment, so systems will work with and rely on natural processes rather than resisting them. Implementing these new integrated systems will reduce current requirements for active management, which are resource-intensive and expensive.

  1. Performance Measurement Analysis System

    Energy Science and Technology Software Center (ESTSC)

    1989-06-01

    The PMAS4.0 (Performance Measurement Analysis System) is a user-oriented system designed to track the cost and schedule performance of Department of Energy (DOE) major projects (MPs) and major system acquisitions (MSAs) reporting under DOE Order 5700.4A, Project Management System. PMAS4.0 provides for the analysis of performance measurement data produced from management control systems complying with the Federal Government''s Cost and Schedule Control Systems Criteria.

  2. Spacecraft systems engineering: An introduction to the process at GSFC

    NASA Technical Reports Server (NTRS)

    Fragomeni, Tony; Ryschkewitsch, Michael G.

    1993-01-01

    The main objective in systems engineering is to devise a coherent total system design capable of achieving the stated requirements. Requirements should be rigid. However, they should be continuously challenged, rechallenged and/or validated. The systems engineer must specify every requirement in order to design, document, implement and conduct the mission. Each and every requirement must be logically considered, traceable and evaluated through various analysis and trade studies in a total systems design. Margins must be determined to be realistic as well as adequate. The systems engineer must also continuously close the loop and verify system performance against the requirements. The fundamental role of the systems engineer, however, is to engineer, not manage. Yet, in large, complex missions, where more than one systems engineer is required, someone needs to manage the systems engineers, and we call them 'systems managers.' Systems engineering management is an overview function which plans, guides, monitors and controls the technical execution of a project as implemented by the systems engineers. As the project moves on through Phases A and B into Phase C/D, the systems engineering tasks become a small portion of the total effort. The systems management role increases since discipline subsystem engineers are conducting analyses and reviewing test data for final review and acceptance by the systems managers.

  3. Management issues in systems engineering

    NASA Technical Reports Server (NTRS)

    Shishko, Robert; Chamberlain, Robert G.; Aster, Robert; Bilardo, Vincent; Forsberg, Kevin; Mooz, Hal; Polaski, Lou; Wade, Ron

    1993-01-01

    When applied to a system, the doctrine of successive refinement is a divide-and-conquer strategy. Complex systems are sucessively divided into pieces that are less complex, until they are simple enough to be conquered. This decomposition results in several structures for describing the product system and the producing system. These structures play important roles in systems engineering and project management. Many of the remaining sections in this chapter are devoted to describing some of these key structures. Structures that describe the product system include, but are not limited to, the requirements tree, system architecture and certain symbolic information such as system drawings, schematics, and data bases. The structures that describe the producing system include the project's work breakdown, schedules, cost accounts and organization.

  4. Management System for Engineering Ethics

    NASA Astrophysics Data System (ADS)

    Yashiro, Tomonari

    In the context of independent profession based societies, ethics charter/codes of professional bodies have significant influence on the conduct of engineers. Contrarily in Japan, most of active engineers are in-house and feel immediate identity as the member of firm or institution, rather than professional bodies. Therefore, establishment and operation of engineering ethics management system (E2ms) is essential for incentive to make innovative and ethical decision with confidence. The paper introduces the outline of the educational kit for E2ms developed by the author. The kit aims to enhance ability of management relevant to E2ms. The kit also involves ten cases for case method teaching. The test use of the kit indicates the potential to create satisfactory educational achievement.

  5. Gas turbine engine control system

    NASA Technical Reports Server (NTRS)

    Idelchik, Michael S. (Inventor)

    1991-01-01

    A control system and method of controlling a gas turbine engine. The control system receives an error signal and processes the error signal to form a primary fuel control signal. The control system also receives at least one anticipatory demand signal and processes the signal to form an anticipatory fuel control signal. The control system adjusts the value of the anticipatory fuel control signal based on the value of the error signal to form an adjusted anticipatory signal and then the adjusted anticipatory fuel control signal and the primary fuel control signal are combined to form a fuel command signal.

  6. Subsonic Performance of Ejector Systems

    NASA Astrophysics Data System (ADS)

    Weil, Samuel

    Combined cycle engines combining scramjets with turbo jets or rockets can provide efficient hypersonic flight. Ejectors have the potential to increase the thrust and efficiency of combined cycle engines near static conditions. A computer code was developed to support the design of a small-scale, turbine-based combined cycle demonstrator with an ejector, built around a commercially available turbojet engine. This code was used to analyze the performance of an ejector system built around a micro-turbojet. With the use of a simple ejector, net thrust increases as large as 20% over the base engine were predicted. Additionally the specific fuel consumption was lowered by 10%. Increasing the secondary to primary area ratio of the ejector lead to significant improvements in static thrust, specific fuel consumption (SFC), and propulsive efficiency. Further ejector performance improvements can be achieved by using a diffuser. Ejector performance drops off rapidly with increasing Mach number. The ejector has lower thrust and higher SFC than the turbojet core at Mach numbers above 0.2. When the nozzle chokes a significant drop in ejector performance is seen. When a diffuser is used, higher Mach numbers lead to choking in the mixer and a shock in the nozzle causing a significant decrease in ejector performance. Evaluation of different turbo jets shows that ejector performance depends significantly on the properties of the turbojet. Static thrust and SFC improvements can be achieved with increasing ejector area for all engines, but size of increase and change in performance at higher Mach numbers depend heavily on the turbojet. The use of an ejector in a turbine based combined cycle configuration also increases performance at static conditions with a thrust increase of 5% and SFC decrease of 5% for the tested configuration.

  7. Aerothermodynamic systems engineering and design

    NASA Astrophysics Data System (ADS)

    A reference source for various aspects of aerothermodynamic systems engineering and design is presented. Air conditioning load analysis is addressed, including physiological requirements, heat and cooling load equations, skin temperature computational methods, cooling loads due to radiation through transparent areas, heating and cooling loads due to internal sources, and practical considerations in the determination of overall heating and cooling loads. Refrigeration system design is considered, including air cycle systems, vapor cycle systems, combined vapor cycle and air cycle systems, and thermoelectric cooling. Heating methods is heating system design and low pressure and high pressure systems in air distribution system design are addressed. Procedures and equations commonly used for aerospace applications of these technologies are included.

  8. AiResearch QCGAT engine performance and emissions tests

    NASA Technical Reports Server (NTRS)

    Norgren, W. M.

    1980-01-01

    Results of aerodynamic performance and emission tests, conducted on a specially designed QCGAT engine in the 17,793-N (4,000 lb) thrust class, are presented. Performance of the AiResearch QCGAT engine was excellent throughout all testing. No serious mechanical malfunctions were encountered, and no significant test time was lost due to engine-related problems. Emissions were drastically reduced over similar engines, and the engine exhibited good smoke performance.

  9. Midtemperature Solar Systems Test Facility predictions for thermal performance based on test data: Custom Engineering trough with glass reflector surface and Sandia-designed receivers

    SciTech Connect

    Harrison, T.D.

    1981-05-01

    Thermal performance predictions based on test data are presented for the Custom Engineering trough and Sandia-designed receivers, with glass reflector surface, for three output temperatures at five cities in the United States. Two experimental receivers were tested, one with an antireflective coating on the glass envelope around the receiver tube and one without the antireflective coating.

  10. The engineering of cybernetic systems

    NASA Astrophysics Data System (ADS)

    Fry, Robert L.

    2002-05-01

    This tutorial develops a logical basis for the engineering of systems that operate cybernetically. The term cybernetic system has a clear quantitative definition. It is a system that dynamically matches acquired information to selected actions relative to a computational issue that defines the essential purpose of the system or machine. This notion requires that information and control be further quantified. The logic of questions and assertions as developed by Cox provides one means of doing this. The design and operation of cybernetic systems can be understood by contrasting these kinds of systems with communication systems and information theory as developed by Shannon. The joint logic of questions and assertions can be seen to underlie and be common to both information theory as applied to the design of discrete communication systems and to a theory of discrete general systems. The joint logic captures a natural complementarity between systems that transmit and receive information and those that acquire and act on it. Specific comparisons and contrasts are made between the source rate and channel capacity of a communication system and the acquisition rate and control capacity of a general system. An overview is provided of the joint logic of questions and assertions and the ties that this logic has to both conventional information theory and to a general theory of systems. I-diagrams, the interrogative complement of Venn diagrams, are described as providing valuable reasoning tools. An initial framework is suggested for the design of cybernetic systems. Two examples are given to illustrate this framework as applied to discrete cybernetic systems. These examples include a predator-prey problem as illustrated through "The Dog Chrysippus Pursuing its Prey," and the derivation of a single-neuron system that operates cybernetically and is biologically plausible. Future areas of research are highlighted which require development for a mature engineering framework.

  11. Developments in REDES: The rocket engine design expert system

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) is being developed at the NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP, a nozzle design program named RAO, a regenerative cooling channel performance evaluation code named RTE, and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES is built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  12. Developments in REDES: The Rocket Engine Design Expert System

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) was developed at NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP; a nozzle design program named RAO; a regenerative cooling channel performance evaluation code named RTE; and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES was built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  13. Test experience, 490 N high performance (321 sec Isp) engine

    NASA Technical Reports Server (NTRS)

    Schoenman, L.; Rosenberg, S. D.; Jassowski, D. M.

    1992-01-01

    Engines with area ratios of 44:1 and 286:1 are tested by means of hot fire tests using the NTO/MMH bipropellant to maximize the performance of the combined technologies. The low-thrust engine systems are designed with oxidation resistant materials that can operate at temperatures of more than 2204 C for tens of hours. The chamber is attached to the injector in a configuration that prevents overheating of the injector, valve, and the spacecraft interface. Three injectors with 44:1 area ratios are capable of nominal specific impulse values of 309 sec, and a performance of 321 lbf-sec/lbm is noted for an all-welded engine assembly with area ratio of 286:1. The all-welded engine is shown to have an acceptable design margin for thermal characteristics. High-performance liquid apogee engines are shown to perform optimally when based on iridium/rhenium chamber technology, use of a special platelet injector, and the minimization of losses due to fuel-film cooling.

  14. An EHF telecommunication system engineering model

    NASA Astrophysics Data System (ADS)

    Allen, Kenneth C.

    1987-11-01

    An extremely high frequency telecommunication system engineering model (ETSEM) was developed as an aid in the design of line-of-sight (LOS) communication systems from 10 to 100 GHz. ETSEM provides tabulation of path geometry parameters and analyzes ray path and Fresnel zone clearances to help the engineer design the path. ETSEM also predicts the performance (availability) of both digital and analog systems based on state-of-the-art EHF propagation models and equipment specifications. Attenuation by rain, clear air absorption and multipath are modeled. These are expected essentially to determine the statistics of link availability as limited by propagation impairments. Performance may be predicted by any interval of months of the year. A climatological data base for North America and Europe provides parameters for the propagation models. ETSEM has been implemented on a desk top computer. Weaknesses and limitations of the model are discussed.

  15. Information technology security system engineering methodology

    NASA Technical Reports Server (NTRS)

    Childs, D.

    2003-01-01

    A methodology is described for system engineering security into large information technology systems under development. The methodology is an integration of a risk management process and a generic system development life cycle process. The methodology is to be used by Security System Engineers to effectively engineer and integrate information technology security into a target system as it progresses through the development life cycle. The methodology can also be used to re-engineer security into a legacy system.

  16. Experimental Study on Revetec Engine Cam Performance

    NASA Astrophysics Data System (ADS)

    Mohyeldin Gasim, Maisara; Giok Chui, Lee; Anwar, Khirul Azhar bin

    2012-09-01

    In Revetec engine (three-lobed) cam replaces the crankshaft to convert the reciprocating motion of the engine piston, to a rotating motion in the drive line. Since the cam controls the piston movement, the cam profile has a great effect on engine performance. In this paper an experimental study was done to a (three- lobed) cam with Cycloidal motion profile but with different ratios between the base circle radius of the cam and the radius of the roller follower. DEWESoft was used to find the displacement and the vibration of the piston, and compare the actual results from the test with the theoretical results from the cam profile equation. The results showed that there is a periods of miss contact between the follower and the cam when the ratio between the base circle radius of the cam and the radius of the roller follower is less than a certain value, and also increasing of vibration. The suggested ratio between the cam and follower radius is to be more than 2:1.

  17. Deep Space Telecommunications Systems Engineering

    NASA Technical Reports Server (NTRS)

    Yuen, J. H. (Editor)

    1982-01-01

    Descriptive and analytical information useful for the optimal design, specification, and performance evaluation of deep space telecommunications systems is presented. Telemetry, tracking, and command systems, receiver design, spacecraft antennas, frequency selection, interference, and modulation techniques are addressed.

  18. Collaborative Systems Thinking: A Response to the Problems Faced by Systems Engineering's 'Middle Tier'

    NASA Technical Reports Server (NTRS)

    Phfarr, Barbara B.; So, Maria M.; Lamb, Caroline Twomey; Rhodes, Donna H.

    2009-01-01

    Experienced systems engineers are adept at more than implementing systems engineering processes: they utilize systems thinking to solve complex engineering problems. Within the space industry demographics and economic pressures are reducing the number of experienced systems engineers that will be available in the future. Collaborative systems thinking within systems engineering teams is proposed as a way to integrate systems engineers of various experience levels to handle complex systems engineering challenges. This paper uses the GOES-R Program Systems Engineering team to illustrate the enablers and barriers to team level systems thinking and to identify ways in which performance could be improved. Ways NASA could expand its engineering training to promote team-level systems thinking are proposed.

  19. Human performance models for computer-aided engineering

    NASA Technical Reports Server (NTRS)

    Elkind, Jerome I. (Editor); Card, Stuart K. (Editor); Hochberg, Julian (Editor); Huey, Beverly Messick (Editor)

    1989-01-01

    This report discusses a topic important to the field of computational human factors: models of human performance and their use in computer-based engineering facilities for the design of complex systems. It focuses on a particular human factors design problem -- the design of cockpit systems for advanced helicopters -- and on a particular aspect of human performance -- vision and related cognitive functions. By focusing in this way, the authors were able to address the selected topics in some depth and develop findings and recommendations that they believe have application to many other aspects of human performance and to other design domains.

  20. Adaptive Optimization of Aircraft Engine Performance Using Neural Networks

    NASA Technical Reports Server (NTRS)

    Simon, Donald L.; Long, Theresa W.

    1995-01-01

    Preliminary results are presented on the development of an adaptive neural network based control algorithm to enhance aircraft engine performance. This work builds upon a previous National Aeronautics and Space Administration (NASA) effort known as Performance Seeking Control (PSC). PSC is an adaptive control algorithm which contains a model of the aircraft's propulsion system which is updated on-line to match the operation of the aircraft's actual propulsion system. Information from the on-line model is used to adapt the control system during flight to allow optimal operation of the aircraft's propulsion system (inlet, engine, and nozzle) to improve aircraft engine performance without compromising reliability or operability. Performance Seeking Control has been shown to yield reductions in fuel flow, increases in thrust, and reductions in engine fan turbine inlet temperature. The neural network based adaptive control, like PSC, will contain a model of the propulsion system which will be used to calculate optimal control commands on-line. Hopes are that it will be able to provide some additional benefits above and beyond those of PSC. The PSC algorithm is computationally intensive, it is valid only at near steady-state flight conditions, and it has no way to adapt or learn on-line. These issues are being addressed in the development of the optimal neural controller. Specialized neural network processing hardware is being developed to run the software, the algorithm will be valid at steady-state and transient conditions, and will take advantage of the on-line learning capability of neural networks. Future plans include testing the neural network software and hardware prototype against an aircraft engine simulation. In this paper, the proposed neural network software and hardware is described and preliminary neural network training results are presented.

  1. Performance of a RBCC Engine in Rocket-Operation

    NASA Astrophysics Data System (ADS)

    Tomioka, Sadatake; Kubo, Takahiro; Noboru Sakuranaka; Tani, Koichiro

    Combination of a scramjet (supersonic combustion ramjet) flow-pass with embedded rocket engines (the combined system termed as Rocket-based Combined Cycle engine) are expected to be the most effective propulsion system for space launch vehicles. Either SSTO (Single Stage To Orbit) system or TSTO (Two Stage To Orbit) system with separation at high altitude needs final stage acceleration in space, so that the RBCC (Rocket Based Combined Cycle) engine should be operated as rocket engines. Performance of the scramjet combustor as the extension to the rocket nozzle, was experimentally evaluated by injecting inert gas at various pressure through the embedded rocket chamber while the whole sub-scaled model was placed in a low pressure chamber connected to an air-driven ejector system. The results showed that the thrust coefficient was about 1.2, the low value being found to mainly due to the friction force on the scramjet combustor wall, while blocking the scramjet flow pass’s opening to increase nozzle extension thrust surface, was found to have little effects on the thrust performance. The combustor was shortened to reduce the friction loss, however, degree of reduction was limited as friction decreased rapidly with distance from the onset of the scramjet combustor.

  2. Heat engine generator control system

    DOEpatents

    Rajashekara, K.; Gorti, B.V.; McMullen, S.R.; Raibert, R.J.

    1998-05-12

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power. 8 figs.

  3. Heat engine generator control system

    DOEpatents

    Rajashekara, Kaushik; Gorti, Bhanuprasad Venkata; McMullen, Steven Robert; Raibert, Robert Joseph

    1998-01-01

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power.

  4. Solar dish/engine systems

    SciTech Connect

    Not Available

    1998-04-01

    Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun`s rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.

  5. Effect of Modifications to Induction System on Altitude Performance of V-1710-93 Engine III : Use of Parabolic Rotating Guide Vanes and NACA Designed Auxiliary-stage Inlet Elbow and Interstage Duct

    NASA Technical Reports Server (NTRS)

    Standahar, Ray M; Mccarty, James S

    1947-01-01

    Bench runs of a modified V-1710-93 engine equipped with a two-stage supercharger, interstage carburetor, aftercooler assembly, and backfire screens have been made at a simulated altitude of 29,000 feet to determine the effect of several induction-system modifications on the engine and supercharger performance. The standard guide vanes on the auxiliary- and engine-stage superchargers were replaced by rotating guide vanes with a parabolic blade profile. The auxiliary-stage inlet elbow and interstage duct were replaced with new units of NACA design. These modifications were made one at a time and data were obtained after each change to determine the effect of each modification. All runs were made at a constant engine speed of 3000 rpm at a simulated altitude of 29,000 feet and all changes in engine power were made by varying the speed of the auxiliary-stage supercharger.

  6. Pressure measurement. [liquid monopropellant rocket engine performance tests

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Practices are outlined for the design, installation, checkout, calibration, and operation of a pressure measuring system to be used during tests of a liquid monopropellant rocket engine. Appendixes include: (1) pressure measurement system elemental uncertainties; (2) short- and long-term pressure measurement system uncertainty; (3) shunt calibration of pressure transducers; (4) special considerations for vacuum measurement; and (5) methods of determining the dynamic characteristics of pressure transducers. Design guidelines are provided for the critical components of each portion of the system to provide a pressure measurement system which meets the performance criteria specified.

  7. Altitude Performance and Operational Characteristics of 29-inch-diameter Tail-pipe Burner with Several Fuel Systems and Flame Holders on J35 Turbojet Engine

    NASA Technical Reports Server (NTRS)

    Conrad, E William; Prince, William R

    1949-01-01

    An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning has been conducted in the NACA Lewis altitude wind tunnel. Several fuel systems and flame holders were investigated in a 29-inch-diameter tail-pipe burner to determine the effect of fuel distribution and flame-holder design on tail-pipe-burner performance and operational characteristics over a range of simulated flight conditions. At an altitude of 5000 feet, the type of flame holder used had only a slight effect on the combustion efficiency. As the altitude was increased, the decrease in peak combustion efficiency became more rapid as the blocking area of the flame holder was reduced. At all altitudes investigated, an improvement in the uniformity of the radial distribution of fuel and air slightly increased the peak combustion efficiencies and shifted the peak combustion efficiency to higher tail-pipe fuel-air ratios. The use of an internal cooling liner extending the full length of the tail-pipe combustion chamber provided adequate shell cooling at all flight conditions investigated.

  8. SMAP Instrument Mechanical System Engineering

    NASA Technical Reports Server (NTRS)

    Slimko, Eric; French, Richard; Riggs, Benjamin

    2013-01-01

    The Soil Moisture Active Passive (SMAP) mission, scheduled for launch by the end of 2014, is being developed to measure the soil moisture and soil freeze/thaw state on a global scale over a three-year period. The accuracy, resolution, and global coverage of SMAP measurements are invaluable across many science and applications disciplines including hydrology, climate, carbon cycle, and the meteorological, environment, and ecology applications communities. The SMAP observatory is composed of a despun bus and a spinning instrument platform that includes both a deployable 6 meter aperture low structural frequency Astromesh reflector and a spin control system. The instrument section has engendered challenging mechanical system issues associated with the antenna deployment, flexible antenna pointing in the context of a multitude of disturbances, spun section mass properties, spin control system development, and overall integration with the flight system on both mechanical and control system levels. Moreover, the multitude of organizations involved, including two major vendors providing the spin subsystem and reflector boom assembly plus the flight system mechanical and guidance, navigation, and control teams, has led to several unique system engineering challenges. Capturing the key physics associated with the function of the flight system has been challenging due to the many different domains that are applicable. Key interfaces and operational concepts have led to complex negotiations because of the large number of organizations that integrate with the instrument mechanical system. Additionally, the verification and validation concerns associated with the mechanical system have had required far-reaching involvement from both the flight system and other subsystems. The SMAP instrument mechanical systems engineering issues and their solutions are described in this paper.

  9. Transient performance of fan engine with water ingestion

    NASA Technical Reports Server (NTRS)

    Murthy, S. N. B.; Mullican, A.

    1993-01-01

    In a continuing investigation on developing and applying codes for prediction of performance of a turbine jet engine and its components with water ingestion during flight operation, including power settings, and flight altitudes and speed changes, an attempt was made to establish the effects of water ingestion through simulation of a generic high bypass ratio engine with a generic control. In view of the large effects arising in the air compression system and the prediffuser-combustor unit during water ingestion, attention was focused on those effects and the resulting changes in engine performance. Under all conditions of operation, whether ingestion is steady or not, it became evident that water ingestion causes a fan-compressor unit to operate in a time-dependent fashion with periodic features, particularly with respect to the state of water in the span and the film in the casing clearance space, at the exit of the machine. On the other hand, the aerodynamic performance of the unit may be considered as quasi-steady once the distribution of water has attained an equilibrium state with respect to its distribution and motion. For purposes of engine simulation, the performance maps for the generic fan-compressor unit were generated based on the attainment of a quasi-steady state (meaning steady except for long-period variations in performance) during ingestion and operation over a wide enough range of rotational speeds.

  10. A systems engineering view of the human in space

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1987-01-01

    A model of the human as an 'engineered' system provides a starting point for determining human requirements and performance on an equivalent basis with technological systems. The human as an engineered system with performance requirements is defined to consist of four subsystems: cognitive, psychological, biomechanical, and biomedical. It is suggested that the treatment of the psychological subsystem as one that modulates the efficiency and quality of human performance offers a particular approach for examining and characterizing psychological effects.

  11. Systems engineering: A problem of perception

    SciTech Connect

    Senglaub, M.

    1995-08-01

    The characterization of systems engineering as a discipline, process, procedure or a set of heuristics will have an impact on the implementation strategy, the training methodology, and operational environment. The systems engineering upgrade activities in the New Mexico Weapons Development Center and a search of systems engineering related information provides evidence of a degree of ambiguity in this characterization of systems engineering. A case is made in this article for systems engineering being the engineering discipline applied to the science of complexity. Implications of this characterization and some generic issues are delineated with the goal of providing an enterprise with a starting point for developing its business environment.

  12. Performance assessment of engineered barriers using the vault model

    SciTech Connect

    Johnson, L.H.

    1993-12-31

    The Vault Model for assessing engineered barrier performance has been developed as part of the preparation of an Environmental Impact Statement to be presented to a Federal Environmental Assessment Review Panel reviewing the Canadian nuclear fuel waste disposal concept. The model describes the behavior of titanium containers, radionuclide release from used fuel, and migration of radionuclides through buffer and backfill materials and into the surrounding geosphere. Vault Model simulations have shown that the release of radionuclides from the engineered barrier system is dominated by the release from the fuel-sheath gap and grain boundaries in used fuel. Sensitivity and uncertainty analyses have illustrated how releases from the vault are affected by both the uncertainty in model parameters and the assumptions made in the development of the models. It is likely that the combined effects of a number of conservatisms in the model result in the releases from the engineered barrier system being overpredicted by several orders of magnitude.

  13. Stirling Engine Dynamic System Modeling

    NASA Technical Reports Server (NTRS)

    Nakis, Christopher G.

    2004-01-01

    The Thermo-Mechanical systems branch at the Glenn Research Center focuses a large amount time on Stirling engines. These engines will be used on missions where solar power is inefficient, especially in deep space. I work with Tim Regan and Ed Lewandowski who are currently developing and validating a mathematical model for the Stirling engines. This model incorporates all aspects of the system including, mechanical, electrical and thermodynamic components. Modeling is done through Simplorer, a program capable of running simulations of the model. Once created and then proven to be accurate, a model is used for developing new ideas for engine design. My largest specific project involves varying key parameters in the model and quantifying the results. This can all be done relatively trouble-free with the help of Simplorer. Once the model is complete, Simplorer will do all the necessary calculations. The more complicated part of this project is determining which parameters to vary. Finding key parameters depends on the potential for a value to be independently altered in the design. For example, a change in one dimension may lead to a proportional change to the rest of the model, and no real progress is made. Also, the ability for a changed value to have a substantial impact on the outputs of the system is important. Results will be condensed into graphs and tables with the purpose of better communication and understanding of the data. With the changing of these parameters, a more optimal design can be created without having to purchase or build any models. Also, hours and hours of results can be simulated in minutes. In the long run, using mathematical models can save time and money. Along with this project, I have many other smaller assignments throughout the summer. My main goal is to assist in the processes of model development, validation and testing.

  14. The Systems Engineering Process for Human Support Technology Development

    NASA Technical Reports Server (NTRS)

    Jones, Harry

    2005-01-01

    Systems engineering is designing and optimizing systems. This paper reviews the systems engineering process and indicates how it can be applied in the development of advanced human support systems. Systems engineering develops the performance requirements, subsystem specifications, and detailed designs needed to construct a desired system. Systems design is difficult, requiring both art and science and balancing human and technical considerations. The essential systems engineering activity is trading off and compromising between competing objectives such as performance and cost, schedule and risk. Systems engineering is not a complete independent process. It usually supports a system development project. This review emphasizes the NASA project management process as described in NASA Procedural Requirement (NPR) 7120.5B. The process is a top down phased approach that includes the most fundamental activities of systems engineering - requirements definition, systems analysis, and design. NPR 7120.5B also requires projects to perform the engineering analyses needed to ensure that the system will operate correctly with regard to reliability, safety, risk, cost, and human factors. We review the system development project process, the standard systems engineering design methodology, and some of the specialized systems analysis techniques. We will discuss how they could apply to advanced human support systems development. The purpose of advanced systems development is not directly to supply human space flight hardware, but rather to provide superior candidate systems that will be selected for implementation by future missions. The most direct application of systems engineering is in guiding the development of prototype and flight experiment hardware. However, anticipatory systems engineering of possible future flight systems would be useful in identifying the most promising development projects.

  15. Space Shuttle Main Engine performance analysis

    NASA Technical Reports Server (NTRS)

    Santi, L. Michael

    1993-01-01

    For a number of years, NASA has relied primarily upon periodically updated versions of Rocketdyne's power balance model (PBM) to provide space shuttle main engine (SSME) steady-state performance prediction. A recent computational study indicated that PBM predictions do not satisfy fundamental energy conservation principles. More recently, SSME test results provided by the Technology Test Bed (TTB) program have indicated significant discrepancies between PBM flow and temperature predictions and TTB observations. Results of these investigations have diminished confidence in the predictions provided by PBM, and motivated the development of new computational tools for supporting SSME performance analysis. A multivariate least squares regression algorithm was developed and implemented during this effort in order to efficiently characterize TTB data. This procedure, called the 'gains model,' was used to approximate the variation of SSME performance parameters such as flow rate, pressure, temperature, speed, and assorted hardware characteristics in terms of six assumed independent influences. These six influences were engine power level, mixture ratio, fuel inlet pressure and temperature, and oxidizer inlet pressure and temperature. A BFGS optimization algorithm provided the base procedure for determining regression coefficients for both linear and full quadratic approximations of parameter variation. Statistical information relative to data deviation from regression derived relations was also computed. A new strategy for integrating test data with theoretical performance prediction was also investigated. The current integration procedure employed by PBM treats test data as pristine and adjusts hardware characteristics in a heuristic manner to achieve engine balance. Within PBM, this integration procedure is called 'data reduction.' By contrast, the new data integration procedure, termed 'reconciliation,' uses mathematical optimization techniques, and requires both

  16. Space Shuttle Main Engine performance analysis

    NASA Astrophysics Data System (ADS)

    Santi, L. Michael

    1993-11-01

    For a number of years, NASA has relied primarily upon periodically updated versions of Rocketdyne's power balance model (PBM) to provide space shuttle main engine (SSME) steady-state performance prediction. A recent computational study indicated that PBM predictions do not satisfy fundamental energy conservation principles. More recently, SSME test results provided by the Technology Test Bed (TTB) program have indicated significant discrepancies between PBM flow and temperature predictions and TTB observations. Results of these investigations have diminished confidence in the predictions provided by PBM, and motivated the development of new computational tools for supporting SSME performance analysis. A multivariate least squares regression algorithm was developed and implemented during this effort in order to efficiently characterize TTB data. This procedure, called the 'gains model,' was used to approximate the variation of SSME performance parameters such as flow rate, pressure, temperature, speed, and assorted hardware characteristics in terms of six assumed independent influences. These six influences were engine power level, mixture ratio, fuel inlet pressure and temperature, and oxidizer inlet pressure and temperature. A BFGS optimization algorithm provided the base procedure for determining regression coefficients for both linear and full quadratic approximations of parameter variation. Statistical information relative to data deviation from regression derived relations was also computed. A new strategy for integrating test data with theoretical performance prediction was also investigated. The current integration procedure employed by PBM treats test data as pristine and adjusts hardware characteristics in a heuristic manner to achieve engine balance. Within PBM, this integration procedure is called 'data reduction.' By contrast, the new data integration procedure, termed 'reconciliation,' uses mathematical optimization techniques, and requires both

  17. Thermal and Environmental Barrier Coatings for Advanced Propulsion Engine Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dong-Ming; Miller, Robert A.

    2004-01-01

    Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. For future high performance engines, the development of advanced ceramic barrier coating systems will allow these coatings to be used to simultaneously increase engine operating temperature and reduce cooling requirements, thereby leading to significant improvements in engine power density and efficiency. In order to meet future engine performance and reliability requirements, the coating systems must be designed with increased high temperature stability, lower thermal conductivity, and improved thermal stress and erosion resistance. In this paper, ceramic coating design and testing considerations will be described for high temperature and high-heat-flux engine applications in hot corrosion and oxidation, erosion, and combustion water vapor environments. Further coating performance and life improvements will be expected by utilizing advanced coating architecture design, composition optimization, and improved processing techniques, in conjunction with modeling and design tools.

  18. Multimedia Feedback Systems for Engineering

    SciTech Connect

    Gladwell, S.; Gottlieb, E.J.; McDonald, M.J.; Slutter, C.L.

    1998-12-15

    The World Wide Web has become a key tool for information sharing. Engineers and scientists are finding that the web is especially suited to publishing the graphical, multi-layered information that is typical of their work. Web pages are easier to distribute than hardcopy. Web movies have become more accessible, in many offices, than videos. Good VRML viewing software, bundled with most new PCs, has sufficient power to support many engineering needs. In addition to publishing information science and engineering has an important tradition of peer and customer review. Reports, drawings and graphs are typically printed, distributed, reviewed, marked up, and returned to the author. Adding review comments to paper is easy. When, however, the information is in electronic form, this ease of review goes away. It's hard to write on videos. It's even harder to write comments on animated 3D models. These feedback limitations reduce the value of the information overall. Fortunately, the web can also be a useful tool for collecting peer and customer review information. When properly formed, web reports, movies, and 3D animations can be readily linked to review notes. This paper describes three multimedia feed-back systems that Sandia National Laboratories has developed to tap that potential. Each system allows people to make context-sensitive comments about specific web content and electronically ties the comments back to the web content being referenced. The fuel system ties comments to specific web pages, the second system ties the comments to specific frames of digital movies, and the third ties the comments to specific times and viewpoints within 3D animations. In addition to the technologies, this paper describes how they are being used to support intelligent machine systems design at Sandia.

  19. Pulse Detonation Engine Air Induction System Analysis

    NASA Technical Reports Server (NTRS)

    Pegg, R. J.; Hunter, L. G.; Couch, B. D.

    1996-01-01

    A preliminary mixed-compression inlet design concept for potential pulse-detonation engine (PDE) powered supersonic aircraft was defined and analyzed. The objectives of this research were to conceptually design and integrate an inlet/PDE propulsion system into a supersonic aircraft, perform time-dependent CFD analysis of the inlet flowfield, and to estimate the installed PDE cycle performance. The study was baselined to a NASA Mach 5 Waverider study vehicle in which the baseline over/under turboramjet engines were replaced with a single flowpath PDE propulsion system. As much commonality as possible was maintained with the baseline configuration, including the engine location and forebody lines. Modifications were made to the inlet system's external ramp angles and a rotating cowl lip was incorporated to improve off-design inlet operability and performance. Engines were sized to match the baseline vehicle study's ascent trajectory thrust requirement at Mach 1.2. The majority of this study was focused on a flight Mach number of 3.0. The time-dependent Navier Stokes CFD analyses of a two-dimensional approximation of the inlet was conducted for the Mach 3.0 condition. The Lockheed Martin Tactical Aircraft Systems-developed FALCON CFD code with a two equation 'k-1' turbulence model was used. The downstream PDE was simulated by an array of four sonic nozzles in which the flow areas were rapidly varied in various opening/closing combinations. Results of the CFD study indicated that the inlet design concept operated successfully at the Mach 3.0 condition, satisfying mass capture, total pressure recovery, and operability requirements. Time-dependent analysis indicated that pressure and expansion waves from the simulated valve perturbations did not effect the inlet's operability or performance.

  20. CF6 jet engine performance deterioration results

    NASA Technical Reports Server (NTRS)

    Lewis, R. J.; Humerickhouse, C. E.; Paas, J. E.

    1978-01-01

    The use of the performance baseline from the flight planning manual as a reference to measure changes in cruise fuel flow rates was discussed. For the CF6-6D engine, the introduction of design changes for performance and durability reasons was seen to introduce an average increment relative to this baseline of 3.2% WFM increase at Nl, 2.5% Fn increase at Nl, 0.8% specific fuel consumption (SFC) increase at Fn, and 7 C EGT increase at Nl, while maintaining sufficient SFC margin of the delivered airplane. The effect of revenue service deterioration and performance restoration relative to the reference was shown to be an adder on top of these design effects. A schematic of typical CF6-6D performance through revenue service and airline maintenance is presented in terms of percent cruise SFC relative to an airline datum point (average level upon entering revenue service). The typical changes in SFC margin are shown for airline revenue service through for installations and refurbishments.

  1. Engineering monitoring expert system's developer

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1991-01-01

    This research project is designed to apply artificial intelligence technology including expert systems, dynamic interface of neural networks, and hypertext to construct an expert system developer. The developer environment is specifically suited to building expert systems which monitor the performance of ground support equipment for propulsion systems and testing facilities. The expert system developer, through the use of a graphics interface and a rule network, will be transparent to the user during rule constructing and data scanning of the knowledge base. The project will result in a software system that allows its user to build specific monitoring type expert systems which monitor various equipments used for propulsion systems or ground testing facilities and accrues system performance information in a dynamic knowledge base.

  2. Intelligent Engine Systems: Adaptive Control

    NASA Technical Reports Server (NTRS)

    Gibson, Nathan

    2008-01-01

    We have studied the application of the baseline Model Predictive Control (MPC) algorithm to the control of main fuel flow rate (WF36), variable bleed valve (AE24) and variable stator vane (STP25) control of a simulated high-bypass turbofan engine. Using reference trajectories for thrust and turbine inlet temperature (T41) generated by a simulated new engine, we have examined MPC for tracking these two reference outputs while controlling a deteriorated engine. We have examined the results of MPC control for six different transients: two idle-to-takeoff transients at sea level static (SLS) conditions, one takeoff-to-idle transient at SLS, a Bode power command and reverse Bode power command at 20,000 ft/Mach 0.5, and a reverse Bode transient at 35,000 ft/Mach 0.84. For all cases, our primary focus was on the computational effort required by MPC for varying MPC update rates, control horizons, and prediction horizons. We have also considered the effects of these MPC parameters on the performance of the control, with special emphasis on the thrust tracking error, the peak T41, and the sizes of violations of the constraints on the problem, primarily the booster stall margin limit, which for most cases is the lone constraint that is violated with any frequency.

  3. Professional Issues in System Safety Engineering

    NASA Astrophysics Data System (ADS)

    McDermid, John; Thomas, Martyn; Redmill, Felix

    For many years the profession of system safety engineering has been emerging. This paper argues that the time has now come when it requires recognition, a voice, proper governance and leadership. System safety engineering is an amalgam of many disciplines, in particular, software engineering, safety engineering and management, and systems engineering, and this paper shows that system safety engineering must address the most difficult aspects of all of these. But professional matters extend beyond merely technical considerations, and the paper concludes by showing why there is the need for a new professional body.

  4. Ariel Performance Analysis System

    NASA Astrophysics Data System (ADS)

    Ariel, Gideon B.; Penny, M. A.; Saar, Dany

    1990-08-01

    The Ariel Performance Analysis System is a computer-based system for the measurement, analysis and presentation of human performance. The system is based on a proprietary technique for processing multiple high-speed film and video recordings of a subject's performance. It is noninvasive, and does not require wires, sensors, markers or reflectors. In addition, it is portable and does not require modification of the performing environment. The scale and accuracy of measurement can be set to whatever levels are required by the activity being performed.

  5. Airbreathing combined cycle engine systems

    NASA Technical Reports Server (NTRS)

    Rohde, John

    1992-01-01

    The Air Force and NASA share a common interest in developing advanced propulsion systems for commercial and military aerospace vehicles which require efficient acceleration and cruise operation in the Mach 4 to 6 flight regime. The principle engine of interest is the turboramjet; however, other combined cycles such as the turboscramjet, air turborocket, supercharged ejector ramjet, ejector ramjet, and air liquefaction based propulsion are also of interest. Over the past months careful planning and program implementation have resulted in a number of development efforts that will lead to a broad technology base for those combined cycle propulsion systems. Individual development programs are underway in thermal management, controls materials, endothermic hydrocarbon fuels, air intake systems, nozzle exhaust systems, gas turbines and ramjet ramburners.

  6. Performance and Weight Estimates for an Advanced Open Rotor Engine

    NASA Technical Reports Server (NTRS)

    Hendricks, Eric S.; Tong, Michael T.

    2012-01-01

    NASA s Environmentally Responsible Aviation Project and Subsonic Fixed Wing Project are focused on developing concepts and technologies which may enable dramatic reductions to the environmental impact of future generation subsonic aircraft. The open rotor concept (also historically referred to an unducted fan or advanced turboprop) may allow for the achievement of this objective by reducing engine fuel consumption. To evaluate the potential impact of open rotor engines, cycle modeling and engine weight estimation capabilities have been developed. The initial development of the cycle modeling capabilities in the Numerical Propulsion System Simulation (NPSS) tool was presented in a previous paper. Following that initial development, further advancements have been made to the cycle modeling and weight estimation capabilities for open rotor engines and are presented in this paper. The developed modeling capabilities are used to predict the performance of an advanced open rotor concept using modern counter-rotating propeller designs. Finally, performance and weight estimates for this engine are presented and compared to results from a previous NASA study of advanced geared and direct-drive turbofans.

  7. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    SciTech Connect

    R. Jarek

    2004-11-23

    The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports.

  8. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    SciTech Connect

    G.H. Nieder-Westermann

    2005-04-07

    The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports.

  9. Systems Engineering and Reusable Avionics

    NASA Technical Reports Server (NTRS)

    Conrad, James M.; Murphy, Gloria

    2010-01-01

    One concept for future space flights is to construct building blocks for a wide variety of avionics systems. Once a unit has served its original purpose, it can be removed from the original vehicle and reused in a similar or dissimilar function, depending on the function blocks the unit contains. For example: Once a lunar lander has reached the moon's surface, an engine controller for the Lunar Decent Module would be removed and used for a lunar rover motor control unit or for a Environmental Control Unit for a Lunar Habitat. This senior design project included the investigation of a wide range of functions of space vehicles and possible uses. Specifically, this includes: (1) Determining and specifying the basic functioning blocks of space vehicles. (2) Building and demonstrating a concept model. (3) Showing high reliability is maintained. The specific implementation of this senior design project included a large project team made up of Systems, Electrical, Computer, and Mechanical Engineers/Technologists. The efforts were made up of several sub-groups that each worked on a part of the entire project. The large size and complexity made this project one of the more difficult to manage and advise. Typical projects only have 3-4 students, but this project had 10 students from five different disciplines. This paper describes the difference of this large project compared to typical projects, and the challenges encountered. It also describes how the systems engineering approach was successfully implemented so that the students were able to meet nearly all of the project requirements.

  10. Performance of Gas-Engine Driven Heat Pump Unit

    SciTech Connect

    Abdi Zaltash; Randy Linkous; Randall Wetherington; Patrick Geoghegan; Ed Vineyard; Isaac Mahderekal; Robert Gaylord

    2008-09-30

    Air-conditioning (cooling) for buildings is the single largest use of electricity in the United States (U.S.). This drives summer peak electric demand in much of the U.S. Improved air-conditioning technology thus has the greatest potential impact on the electric grid compared to other technologies that use electricity. Thermally-activated technologies (TAT), such as natural gas engine-driven heat pumps (GHP), can provide overall peak load reduction and electric grid relief for summer peak demand. GHP offers an attractive opportunity for commercial building owners to reduce electric demand charges and operating expenses. Engine-driven systems have several potential advantages over conventional single-speed or single-capacity electric motor-driven units. Among them are variable speed operation, high part load efficiency, high temperature waste heat recovery from the engine, and reduced annual operating costs (SCGC 1998). Although gas engine-driven systems have been in use since the 1960s, current research is resulting in better performance, lower maintenance requirements, and longer operating lifetimes. Gas engine-driven systems are typically more expensive to purchase than comparable electric motor-driven systems, but they typically cost less to operate, especially for commercial building applications. Operating cost savings for commercial applications are primarily driven by electric demand charges. GHP operating costs are dominated by fuel costs, but also include maintenance costs. The reliability of gas cooling equipment has improved in the last few years and maintenance requirements have decreased (SCGC 1998, Yahagi et al. 2006). Another advantage of the GHP over electric motor-driven is the ability to use the heat rejected from the engine during heating operation. The recovered heat can be used to supplement the vapor compression cycle during heating or to supply other process loads, such as water heating. The use of the engine waste heat results in greater

  11. Engineering index : a metric for assessing margin in engineered systems

    SciTech Connect

    Dolin, Ronald M.

    2002-01-01

    Inherent in most engineered products is some measure of margin or over design. Engineers often do not retain design and performance knowledge so they can quantify uncertainties and estimate how much margin their product possesses. When knowledge-capture and quantification is neither possible, nor permissible, engineers rely on cultural lore and institutionalised practices to assign nominal conditions and tolerances. Often what gets lost along the way is design intent, product requirements, and their relationship with the product's intended application. The Engineering Index was developed to assess the goodness or quality of a product.

  12. Characterization of a high-pressure diesel fuel injection system as a control technology option to improve engine performance and reduce exhaust emissions

    NASA Technical Reports Server (NTRS)

    Mcfadden, J. J.; Dezelick, R. A.; Barrows, R. R.

    1983-01-01

    Test results from a high pressure electronically controlled fuel injection system are compared with a commercial mechanical injection system on a single cylinder, diesel test engine using an inlet boost pressure of 2.6:1. The electronic fuel injection system achieved high pressure by means of a fluid intensifier with peak injection pressures of 47 to 69 MPa. Reduced exhaust emissions were demonstrated with an increasing rate of injection followed by a fast cutoff of injection. The reduction in emissions is more responsive to the rate of injection and injection timing than to high peak injection pressure.

  13. Small, high-performance engine component technology status. [liquid rocket engine for spacecraft

    NASA Technical Reports Server (NTRS)

    Yost, M. C.; Csomor, A.

    1976-01-01

    Rocketdyne, under contract to NASA-Lewis Research Center, is engaged in developing the technology for major subsystems of a small, high-performance, liquid rocket engine with the capabilities required for high-energy, upper-stage applications. Included in these efforts are the high-pressure turbopumps, preburner, igniter components, and high-area-ratio thrust chamber. A brief description of the engine system and its subsystems is given. The status of the programs is reviewed and the results of the testing conducted are presented.

  14. Quiet Clean Short-haul Experimental Engine (QCSEE) Over-The-Wing (OTW) propulsion systems test report. Volume 4: Acoustic performance

    NASA Technical Reports Server (NTRS)

    Stimpert, D. L.

    1979-01-01

    A series of acoustic tests were conducted on the over the wing engine. These tests evaluated the fully suppressed noise levels in forward and reverse thrust operation and provided insight into the component noise sources of the engine plus the suppression achieved by various components. System noise levels using the contract specified calculation procedure indicate that the in-flight noise level on a 152 m sideline at takeoff and approach are 97.2 and 94.6 EPNdB, respectively, compared to a goal of 95.0 EPNdB. In reverse thrust, the system noise level was 106.1 PNdB compared to a goal of 100 PNdB. Baseline source noise levels agreed very well with pretest predictions. Inlet-radiated noise suppression of 14 PNdB was demonstrated with the high throat Mach number inlet at 0.79 throat Mach number.

  15. 14 CFR 33.28 - Engine control systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Applicability. These requirements are applicable to any system or device that is part of engine type design..., analysis, or a combination thereof, that the engine control system performs the intended functions in a... envelope; (ii) Complies with the operability requirements of §§ 33.51, 33.65 and 33.73, as...

  16. 14 CFR 33.28 - Engine control systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) Applicability. These requirements are applicable to any system or device that is part of engine type design..., analysis, or a combination thereof, that the engine control system performs the intended functions in a... envelope; (ii) Complies with the operability requirements of §§ 33.51, 33.65 and 33.73, as...

  17. Microwave scanning beam landing system compatibility and performance: Engineering analyses 75-1 and 75-2. [space shuttle orbiter landing

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The microwave scanning beam landing system (MSBLS) is the primary position sensor of the Orbiter's navigation subsystem during the autoland phase of the flight. Portions of the system are discussed with special emphasis placed on potential problem areas as referenced to the Orbiter's mission. Topics discussed include system compatability, system accuracy, and expected RF signal levels. A block and flow diagram of MSBLS system operation is included with a list of special tests required to determine system performance.

  18. Engineering Design Information System (EDIS) user' manual

    SciTech Connect

    Smith, P.S.; Short, R.D.

    1991-11-01

    This manual is a guide to the use of the Engineering Design Information System (EDIS). The system runs on the Martin Marietta Energy Systems, Inc., IBM 3084 unclassified computer. EDIS is in the second phase of implementation, which provides an index, storage, and retrieval system for engineering documents produced at various plants and laboratories operated by Energy Systems for the Department of Energy (DOE). The second phase also provides additional hard copy request functionality. Section 2.0 of this manual presents an overview of EDIS, describing the system's purpose; the functions it performs; hardware, software, and security requirements; and help and error functions. Section 3.0 describes how to access EDIS and how to operate system functions using Database 2 (DB2), Time Sharing Option (TSO), Interactive System Productivity Facility (ISPF), Soft Master viewing, and FT/Express file transfer features employed by this system. Appendix A lists the special hardware and software requirements that must be met to run the View function. Appendix B contains a description of the Soft Master viewing capabilities provided through the EDIS View function. Appendix C contains a list of special hardware and software requirements for the Store and Download functions of EDIS. Appendix D provides examples of the system error screens and help screens for valid codes used for screen entry. Appendix E contains a dictionary of data elements and descriptions.

  19. A Performance Map for Ideal Air Breathing Pulse Detonation Engines

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    2001-01-01

    The performance of an ideal, air breathing Pulse Detonation Engine is described in a manner that is useful for application studies (e.g., as a stand-alone, propulsion system, in combined cycles, or in hybrid turbomachinery cycles). It is shown that the Pulse Detonation Engine may be characterized by an averaged total pressure ratio, which is a unique function of the inlet temperature, the fraction of the inlet flow containing a reacting mixture, and the stoichiometry of the mixture. The inlet temperature and stoichiometry (equivalence ratio) may in turn be combined to form a nondimensional heat addition parameter. For each value of this parameter, the average total enthalpy ratio and total pressure ratio across the device are functions of only the reactant fill fraction. Performance over the entire operating envelope can thus be presented on a single plot of total pressure ratio versus total enthalpy ratio for families of the heat addition parameter. Total pressure ratios are derived from thrust calculations obtained from an experimentally validated, reactive Euler code capable of computing complete Pulse Detonation Engine limit cycles. Results are presented which demonstrate the utility of the described method for assessing performance of the Pulse Detonation Engine in several potential applications. Limitations and assumptions of the analysis are discussed. Details of the particular detonative cycle used for the computations are described.

  20. Cold starting system for alcohol fueled engine

    SciTech Connect

    Powell, T.M.

    1983-04-26

    To restart an alcohol fueled engine at low temperatures, a quantity of liquid ethanol is supplied to a vaporizing chamber before the engine is stopped. When restarting the engine, some of the alcohol in the vaporizing chamber is delivered to an igniter, and the hot gases resulting from the burning alcohol are conducted past the vaporizing chamber to evaporate the liquid alcohol remaining in the vaporizing chamber. The alcohol vapor thus generated is conducted to the engine induction system to start the engine.

  1. Engine cycle design considerations for nuclear thermal propulsion systems

    SciTech Connect

    Pelaccio, D.G.; Scheil, C.M.; Collins, J.T. )

    1993-01-20

    A top-level study was performed which addresses nuclear thermal propulsion system engine cycle options and their applicability to support future Space Exploration Initiative manned lunar and Mars missions. Technical and development issues associated with expander, gas generator, and bleed cycle near-term, solid core nuclear thermal propulsion engines are identified and examined. In addition to performance and weight the influence of the engine cycle type on key design selection parameters such as design complexity, reliability, development time, and cost are discussed. Representative engine designs are presented and compared. Their applicability and performance impact on typical near-term lunar and Mars missions are shown.

  2. Engineering data compendium. Human perception and performance, volume 1

    NASA Technical Reports Server (NTRS)

    Boff, Kenneth R. (Editor); Lincoln, Janet E. (Editor)

    1988-01-01

    The concept underlying the Engineering Data Compendium was the product an R and D program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design of military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by system designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is Volume 1, which contains sections on Visual Acquisition of Information, Auditory Acquisition of Information, and Acquisition of Information by Other Senses.

  3. Engineering data compendium. Human perception and performance, volume 2

    NASA Technical Reports Server (NTRS)

    Boff, Kenneth R. (Editor); Lincoln, Janet E. (Editor)

    1988-01-01

    The concept underlying the Engineering Data Compendium was the product of a Research and Development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design of military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by system designers. The present volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is Volume 2, which contains sections on Information Storage and Retrieval, Spatial Awareness, Perceptual Organization, and Attention and Allocation of Resources.

  4. Engineering data compendium. Human perception and performance. User's guide

    NASA Technical Reports Server (NTRS)

    Boff, Kenneth R. (Editor); Lincoln, Janet E. (Editor)

    1988-01-01

    The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use.

  5. Engineering data compendium. Human perception and performance, volume 3

    NASA Technical Reports Server (NTRS)

    Boff, Kenneth R. (Editor); Lincoln, Janet E. (Editor)

    1988-01-01

    The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design of military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by system designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is Volume 3, containing sections on Human Language Processing, Operator Motion Control, Effects of Environmental Stressors, Display Interfaces, and Control Interfaces (Real/Virtual).

  6. A stirling engine computer model for performance calculations

    NASA Technical Reports Server (NTRS)

    Tew, R.; Jefferies, K.; Miao, D.

    1978-01-01

    To support the development of the Stirling engine as a possible alternative to the automobile spark-ignition engine, the thermodynamic characteristics of the Stirling engine were analyzed and modeled on a computer. The modeling techniques used are presented. The performance of an existing rhombic-drive Stirling engine was simulated by use of this computer program, and some typical results are presented. Engine tests are planned in order to evaluate this model.

  7. Systems Metabolic Engineering of Escherichia coli.

    PubMed

    Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

    2016-05-01

    Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass. PMID:27223822

  8. Biodehalogenation: Natural and engineered systems

    SciTech Connect

    Wackett, L.P.; Lange, C.C.; Ornstein, R.L.

    1995-12-31

    Many halogenated organic compounds are environmentally persistent pollutants. Environmental persistence results from the failure of most microorganisms to metabolize organohalides. The authors are studying some of the microbial successes, natural isolates that catalyze carbon-halogen bond cleavage reactions, and subsequent recycling of the compounds into the carbon cycle. Knowledge derived from studies of naturally evolved genes and enzymes provides a basis for directed laboratory evolution of new biological systems that are active with the most environmentally persistent polyhalogenated compounds. The complete metabolism of polyhalogenated compounds typically requires sequential reductive and oxidative dehalogenation reactions. The authors genetically constructed a Pseudomonas putida strain containing seven genes encoding two multicomponent enzyme systems, i.e., cytochrome P450{sub CAM} and toluene dioxygenase. This laboratory-designed metabolic pathway catalyzed sequential reductive and oxidative dehalogenation reactions with fluorinated, chlorinated, and brominated compounds. Current efforts are focused on directed evolution experiments to improve the efficacy of the engineered pathway.

  9. System engineering approach to GPM retrieval algorithms

    SciTech Connect

    Rose, C. R.; Chandrasekar, V.

    2004-01-01

    System engineering principles and methods are very useful in large-scale complex systems for developing the engineering requirements from end-user needs. Integrating research into system engineering is a challenging task. The proposed Global Precipitation Mission (GPM) satellite will use a dual-wavelength precipitation radar to measure and map global precipitation with unprecedented accuracy, resolution and areal coverage. The satellite vehicle, precipitation radars, retrieval algorithms, and ground validation (GV) functions are all critical subsystems of the overall GPM system and each contributes to the success of the mission. Errors in the radar measurements and models can adversely affect the retrieved output values. Ground validation (GV) systems are intended to provide timely feedback to the satellite and retrieval algorithms based on measured data. These GV sites will consist of radars and DSD measurement systems and also have intrinsic constraints. One of the retrieval algorithms being studied for use with GPM is the dual-wavelength DSD algorithm that does not use the surface reference technique (SRT). The underlying microphysics of precipitation structures and drop-size distributions (DSDs) dictate the types of models and retrieval algorithms that can be used to estimate precipitation. Many types of dual-wavelength algorithms have been studied. Meneghini (2002) analyzed the performance of single-pass dual-wavelength surface-reference-technique (SRT) based algorithms. Mardiana (2003) demonstrated that a dual-wavelength retrieval algorithm could be successfully used without the use of the SRT. It uses an iterative approach based on measured reflectivities at both wavelengths and complex microphysical models to estimate both No and Do at each range bin. More recently, Liao (2004) proposed a solution to the Do ambiguity problem in rain within the dual-wavelength algorithm and showed a possible melting layer model based on stratified spheres. With the No and Do

  10. Performance deterioration of commercial high-bypass ratio turbofan engines

    NASA Technical Reports Server (NTRS)

    Mehalic, C. M.; Ziemianski, J. A.

    1980-01-01

    The results of engine performance deterioration investigations based on historical data, special engine tests, and specific tests to define the influence of flight loads and component clearances on performance are presented. The results of analyses of several damage mechanisms that contribute to performance deterioration such as blade tip rubs, airfoil surface roughness and erosion, and thermal distortion are also included. The significance of these damage mechanisms on component and overall engine performance is discussed.

  11. The MSFC Systems Engineering Guide: An Overview and Plan

    NASA Technical Reports Server (NTRS)

    Shelby, Jerry A.; Thomas, L. Dale

    2007-01-01

    As systems and subsystems requirements become more complex in the pursuit of the exploration of space, advanced technology will demand and require an integrated approach to the design and development of safe and successful space vehicles and there products. System engineers play a vital and key role in transforming mission needs into vehicle requirements that can be verified and validated. This will result in a safe and cost effective design that will satisfy the mission schedule. A key to successful vehicle design within systems engineering is communication. Communication, through a systems engineering infrastructure, will not only ensure that customers and stakeholders are satisfied but will also assist in identifying vehicle requirements; i.e. identification, integration and management. This vehicle design will produce a system that is verifiable, traceable, and effectively satisfies cost, schedule, performance, and risk throughout the life-cycle of the product. A communication infrastructure will bring about the integration of different engineering disciplines within vehicle design. A system utilizing these aspects will enhance system engineering performance and improve upon required activities such as Development of Requirements, Requirements Management, Functional Analysis, Test, Synthesis, Trade Studies, Documentation, and Lessons Learned to produce a successful final product. This paper will describe the guiding vision, progress to date and the plan forward for development of the Marshall Space Flight Center (MSFC) Systems Engineering Guide (SEG), a virtual systems engineering handbook and archive that will describe the system engineering processes that are used by MSFC in the development of complex systems such as the Ares launch vehicle. It is the intent of this website to be a "One Stop Shop" for our systems engineers that will provide tutorial information, an overview of processes and procedures and links to assist system engineering with guidance and

  12. 49 CFR 240.129 - Criteria for monitoring operational performance of certified engineers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... railroad operates with a signal system that must comply with part 236 of this chapter; (ii) Engineer... performance of those it has determined as qualified as a locomotive engineer in either train or locomotive... each engineer shall be monitored each calendar year by a Designated Supervisor of Locomotive...

  13. 49 CFR 240.129 - Criteria for monitoring operational performance of certified engineers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... railroad operates with a signal system that must comply with part 236 of this chapter; (ii) Engineer... performance of those it has determined as qualified as a locomotive engineer in either train or locomotive... each engineer shall be monitored each calendar year by a Designated Supervisor of Locomotive...

  14. Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. II - Engine Performance. II; Engine Performance

    NASA Technical Reports Server (NTRS)

    Meyer, Carl L.; Bloomer, Harry E.

    1948-01-01

    An investigation was conducted in the NACA Cleveland altitude wind tunnel to evaluate the performance characteristics of the X24C-4B turbojet engine over a range of simulated altitudes from 5000 to 45,000 feet,simulated flight Mach numbers from 0 to 1.08, and engine speeds from 4000 to 12,500 rpm. Performance data are presented to show graphically the effects of altitude at a flight Mach number of 0.25 and of flight Mach number at an altitude of 25,000 feet. The performance data are generalized to show the applicability of methods used to determine performance at any altitude from data obtained at a given altitude. A complete tabulation of performance data, as well as lubrication- and fuel- system data, is presented.

  15. Engine valve operating system for an internal combustion engine

    SciTech Connect

    Hara, S.; Matsumoto, Y.; Matayoshi, Y.

    1986-02-04

    This patent describes an engine valve operating system for an internal combustion engine. The system consists of: a driving cam rotatable in timed relation to engine revolution; a rocker arm having a first end section drivingly connected to an engine valve and a second end section drivably connected to the driving cam; an elongated lever pivoted at a first end section and disposed in fulcrum contact with the rocker arm; an apparatus for biasing the rocker arm and the lever away from each other; and a hydraulic actuator having a movable end section which is in contact with a second end section of the lever and movable to control the pivotal location of the lever in accordance with an engine operating condition.

  16. Systems engineering in the global environment : a wicked future.

    SciTech Connect

    Griego, Regina M.

    2010-12-01

    This presentation discusses the following questions: (1) What are the Global Problems that require Systems Engineering; (2) Where is Systems Engineering going; (3) What are the boundaries of Systems Engineering; (4) What is the distinction between Systems Thinking and Systems Engineering; (5) Can we use Systems Engineering on Complex Systems; and (6) Can we use Systems Engineering on Wicked Problems?

  17. Development of the onboard digital processing system for the soft x-ray spectrometer of ASTRO-H: performance in the engineering model tests

    NASA Astrophysics Data System (ADS)

    Seta, H.; Tashiro, M. S.; Ishisaki, Y.; Tsujimoto, M.; Shimoda, Y.; Takeda, S.; Yamaguchi, S.; Mitsuda, K.; Fujimoto, R.; Takei, Y.; Kelley, R. L.; Boyce, K. R.; Kilbourne, C. A.; Porter, F. S.; Miko, J. J.; Masukawa, K.; Matsuda, K.

    2012-09-01

    We present the development status of the Pulse Shape Processor (PSP), which is the on-board digital electronics responsible for the signal processing of the X-ray microcalorimeter spectrometer instrument (the Soft X-ray Spectrometer; SXS) for the ASTRO-H satellite planned to be launched in 2014. We finished the design and fabrication for the engineering model, and are currently undertaking a series of performance verification and environmental tests. In this report, we summarize the results obtained in a part of the tests completed in the first half of this year.

  18. Real-time in-flight engine performance and health monitoring techniques for flight research application

    NASA Technical Reports Server (NTRS)

    Ray, Ronald J.; Hicks, John W.; Wichman, Keith D.

    1991-01-01

    Procedures for real time evaluation of the inflight health and performance of gas turbine engines and related systems were developed to enhance flight test safety and productivity. These techniques include the monitoring of the engine, the engine control system, thrust vectoring control system health, and the detection of engine stalls. Real time performance techniques were developed for the determination and display of inflight thrust and for aeroperformance drag polars. These new methods were successfully shown on various research aircraft at NASA-Dryden. The capability of NASA's Western Aeronautical Test Range and the advanced data acquisition systems were key factors for implementation and real time display of these methods.

  19. Modification and performance evaluation of a mono-valve engine

    NASA Astrophysics Data System (ADS)

    Behrens, Justin W.

    A four-stroke engine utilizing one tappet valve for both the intake and exhaust gas exchange processes has been built and evaluated. The engine operates under its own power, but has a reduced power capacity than the conventional 2-valve engine. The reduction in power is traced to higher than expected amounts of exhaust gases flowing back into the intake system. Design changes to the cylinder head will fix the back flow problems, but the future capacity of mono-valve engine technology cannot be estimated. The back flow of exhaust gases increases the exhaust gas recirculation (EGR) rate and deteriorates combustion. Intake pressure data shows the mono-valve engine requires an advanced intake valve closing (IVC) time to prevent back flow of charge air. A single actuation camshaft with advanced IVC was tested in the mono-valve engine, and was found to improve exhaust scavenging at TDC and nearly eliminated all charge air back flow at IVC. The optimum IVC timing is shown to be approximately 30 crank angle degrees after BDC. The mono-valve cylinder head utilizes a rotary valve positioned above the tappet valve. The open spaces inside the rotary valveand between the rotary valve and tappet valve represent a common volume that needs to be reduced in order to reduce the base EGR rate. Multiple rotary valve configurations were tested, and the size of the common volume was found to have no effect on back flow but a direct effect on the EGR rate and engine performance. The position of the rotary valve with respect to crank angle has a direct effect on the scavenging process. Optimum scavenging occurs when the intake port is opened just after TDC.

  20. Solar-Powered Electric Propulsion Systems: Engineering and Applications

    NASA Technical Reports Server (NTRS)

    Stearns, J. W.; Kerrisk, D. J.

    1966-01-01

    Lightweight, multikilowatt solar power arrays in conjunction with electric propulsion offer potential improvements to space exploration, extending the usefulness of existing launch vehicles to higher-energy missions. Characteristics of solar-powered electric propulsion missions are outlined, and preliminary performance estimates are shown. Spacecraft system engineering is discussed with respect to parametric trade-offs in power and propulsion system design. Relationships between mission performance and propulsion system performance are illustrated. The present state of the art of electric propulsion systems is reviewed and related to the mission requirements identified earlier. The propulsion system design and test requirements for a mission spacecraft are identified and discussed. Although only ion engine systems are currently available, certain plasma propulsion systems offer some advantages in over-all system design. These are identified, and goals are set for plasma-thrustor systems to make them competitive with ion-engine systems for mission applications.

  1. Hydrogen engine performance analysis project. Second annual report

    SciTech Connect

    Adt, Jr., R. R.; Swain, M. R.; Pappas, J. M.

    1980-01-01

    Progress in a 3 year research program to evaluate the performance and emission characteristics of hydrogen-fueled internal combustion engines is reported. Fifteen hydrogen engine configurations will be subjected to performance and emissions characterization tests. During the first two years, baseline data for throttled and unthrottled, carburetted and timed hydrogen induction, Pre IVC hydrogen-fueled engine configurations, with and without exhaust gas recirculation (EGR) and water injection, were obtained. These data, along with descriptions of the test engine and its components, the test apparatus, experimental techniques, experiments performed and the results obtained, are given. Analyses of other hydrogen-engine project data are also presented and compared with the results of the present effort. The unthrottled engine vis-a-vis the throttled engine is found, in general, to exhibit higher brake thermal efficiency. The unthrottled engine also yields lower NO/sub x/ emissions, which were found to be a strong function of fuel-air equivalence ratio. (LCL)

  2. Performance evaluation of video colonoscope systems

    NASA Astrophysics Data System (ADS)

    Picciano, Lawrence D.; Keller, James P.

    1994-05-01

    A comparative engineering performance evaluation was performed on video colonoscope systems from all three of the current U.S. suppliers: Fujinon, Olympus, and Pentax. Video system test methods, results, and conclusions based on their clinical significance are the focus of this paper.

  3. Performing environmental audits: An engineer's guide

    SciTech Connect

    Morelli, J.A. )

    1994-02-01

    Today, environmental auditing is both a technical exercise and a legal art. To perform a comprehensive and effective environmental audit requires a team of individuals who combined have broad engineering skills, a knowledge of chemistry, and specialized legal experience with all the relevant environmental regulations. Because the audit involves such highly qualified individuals, it is typically quite expensive. Nonetheless, the cost is well worth the investment, because of the high stakes involved in environmental legislation and litigation. Simply put, the cost of non-compliance can far outweigh the costs associated with a comprehensive audit. The paper describes starting the audit, the ideal team, a standard method, doing a compliance audit, data analysis after the audit, advantages and disadvantages, and policies on auditing. The paper briefly describes the four factors that the Department of Justice considers in deciding whether to bring criminal prosecution for violation of an environmental statute. The four factors are: voluntary disclosure; cooperation; preventive measures and compliance program; and pervasiveness of non-compliance.

  4. Intelligent Work Process Engineering System

    NASA Technical Reports Server (NTRS)

    Williams, Kent E.

    2003-01-01

    Optimizing performance on work activities and processes requires metrics of performance for management to monitor and analyze in order to support further improvements in efficiency, effectiveness, safety, reliability and cost. Information systems are therefore required to assist management in making timely, informed decisions regarding these work processes and activities. Currently information systems regarding Space Shuttle maintenance and servicing do not exist to make such timely decisions. The work to be presented details a system which incorporates various automated and intelligent processes and analysis tools to capture organize and analyze work process related data, to make the necessary decisions to meet KSC organizational goals. The advantages and disadvantages of design alternatives to the development of such a system will be discussed including technologies, which would need to bedesigned, prototyped and evaluated.

  5. Integrating system safety into the basic systems engineering process

    NASA Technical Reports Server (NTRS)

    Griswold, J. W.

    1971-01-01

    The basic elements of a systems engineering process are given along with a detailed description of what the safety system requires from the systems engineering process. Also discussed is the safety that the system provides to other subfunctions of systems engineering.

  6. Performance of annular high frequency thermoacoustic engines

    NASA Astrophysics Data System (ADS)

    Rodriguez, Ivan A.

    This thesis presents studies of the behavior of miniature annular thermoacoustic prime movers and the imaging of the complex sound fields using PIV inside the small acoustic wave guides when driven by a temperature gradient. Thermoacoustic engines operating in the standing wave mode are limited in their acoustic efficiency by a high degree of irreversibility that is inherent in how they work. Better performance can be achieved by using traveling waves in the thermoacoustic devices. This has led to the development of an annular high frequency thermoacoustic prime mover consisting of a regenerator, which is a random stack in-between a hot and cold heat exchanger, inside an annular waveguide. Miniature devices were developed and studied with operating frequencies in the range of 2-4 kHz. This corresponds to an average ring circumference of 11 cm for the 3 kHz device, the resonator bore being 6 mm. A similar device of 11 mm bore, length of 18 cm was also investigated; its resonant frequency was 2 kHz. Sound intensities as high as 166.8 dB were generated with limited heat input. Sound power was extracted from the annular structure by an impedance-matching side arm. The nature of the acoustic wave generated by heat was investigated using a high speed PIV instrument. Although the acoustic device appears symmetric, its performance is characterized by a broken symmetry and by perturbations that exist in its structure. Effects of these are observed in the PIV imaging; images show axial and radial components. Moreover, PIV studies show effects of streaming and instabilities which affect the devices' acoustic efficiency. The acoustic efficiency is high, being of 40% of Carnot. This type of device shows much promise as a high efficiency energy converter; it can be reduced in size for microcircuit applications.

  7. Engine sealing and lubrication systems

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1975-01-01

    Engine sealing programs are discussed which are directed toward the two major classes of engine seals: engine shaft seals and primary gas path seals. In addition, some concepts and results from fundamental lubrication research, as it pertains to the lubrication of bearings, are presented.

  8. F100 engine diagnostic system status to date

    NASA Technical Reports Server (NTRS)

    Boyless, J. A.

    1981-01-01

    An engine diagnostic system, proposed for the F100 engine, was tested in five specially modified Tactical Air Command F-15 aircraft during a 16-month flight evaluation. After more than 3300 engine operating hours encompassing almost 900 flights during the flight evaluation, these aircraft provided a data base, still being analyzed, that has shown successful demonstration of the original functional characteristics. Four general design requirements, recording engine operating time/low cycle fatigue event detection, engine trim, and trend and performance data collection were demonstrated. Also, validation of maintenance actions taken and indicated needed maintenance were successfully demonstrated.

  9. Instrumentation & Data Acquisition System (D AS) Engineer

    NASA Technical Reports Server (NTRS)

    Jackson, Markus Deon

    2015-01-01

    The primary job of an Instrumentation and Data Acquisition System (DAS) Engineer is to properly measure physical phenomenon of hardware using appropriate instrumentation and DAS equipment designed to record data during a specified test of the hardware. A DAS system includes a CPU or processor, a data storage device such as a hard drive, a data communication bus such as Universal Serial Bus, software to control the DAS system processes like calibrations, recording of data and processing of data. It also includes signal conditioning amplifiers, and certain sensors for specified measurements. My internship responsibilities have included testing and adjusting Pacific Instruments Model 9355 signal conditioning amplifiers, writing and performing checkout procedures, writing and performing calibration procedures while learning the basics of instrumentation.

  10. How relational systems perform

    SciTech Connect

    Date, C.J.

    1984-02-13

    Contrary to popular belief, relational DBMS can perform at least as well as, and quite possibly better than, older hierarchical or network systems. Ignoring the interference effects introduced when multiple transactions are run in parallel, the author concentrates on the performance of some given database transaction considered in isolation. The two principal factors determining the performance of such a transaction are, of course, the number of I/O operations and the pathlength (amount of CPU processing).

  11. An Ada inference engine for expert systems

    NASA Technical Reports Server (NTRS)

    Lavallee, David B.

    1986-01-01

    The purpose is to investigate the feasibility of using Ada for rule-based expert systems with real-time performance requirements. This includes exploring the Ada features which give improved performance to expert systems as well as optimizing the tradeoffs or workarounds that the use of Ada may require. A prototype inference engine was built using Ada, and rule firing rates in excess of 500 per second were demonstrated on a single MC68000 processor. The knowledge base uses a directed acyclic graph to represent production lines. The graph allows the use of AND, OR, and NOT logical operators. The inference engine uses a combination of both forward and backward chaining in order to reach goals as quickly as possible. Future efforts will include additional investigation of multiprocessing to improve performance and creating a user interface allowing rule input in an Ada-like syntax. Investigation of multitasking and alternate knowledge base representations will help to analyze some of the performance issues as they relate to larger problems.

  12. Computer program for Stirling engine performance calculations

    NASA Technical Reports Server (NTRS)

    Tew, R. C., Jr.

    1983-01-01

    The thermodynamic characteristics of the Stirling engine were analyzed and modeled on a computer to support its development as a possible alternative to the automobile spark ignition engine. The computer model is documented. The documentation includes a user's manual, symbols list, a test case, comparison of model predictions with test results, and a description of the analytical equations used in the model.

  13. Methodology for the systems engineering process. Volume 1: System functional activities

    NASA Technical Reports Server (NTRS)

    Nelson, J. H.

    1972-01-01

    Systems engineering is examined in terms of functional activities that are performed in the conduct of a system definition/design, and system development is described in a parametric analysis that combines functions, performance, and design variables. Emphasis is placed on identification of activities performed by design organizations, design specialty groups, as well as a central systems engineering organizational element. Identification of specific roles and responsibilities for doing functions, and monitoring and controlling activities within the system development operation are also emphasized.

  14. Automotive Stirling engine system component review

    NASA Technical Reports Server (NTRS)

    Hindes, Chip; Stotts, Robert

    1987-01-01

    The design and testing of the power and combustion control system for the basic Stirling engine, Mod II, are examined. The power control system is concerned with transparent operation, and the Mod II uses engine working gas pressure variation to control the power output of the engine. The main components of the power control system, the power control valve, the pump-down system, and the hydrogen stable system, are described. The combustion control system consists of a combustion air supply system and an air/fuel ratio control system, and the system is to maintain constant heater head temperature, and to maximize combustion efficiency and to minimize exhaust emissions.

  15. Titanium in Engine Valve Systems

    NASA Astrophysics Data System (ADS)

    Allison, J. E.; Sherman, A. M.; Bapna, M. R.

    1987-03-01

    Titanium alloys offer a unique combination of high strength-to-weight ratio, good corrosion resistance and favorable high temperature mechanical properties. Still, their relatively high cost has discouraged consideration for widespread use in automotive components. Recent demands for increased fuel economy have led to the consideration of these alloys for use as valve train materials where higher costs might be offset by improvements in performance and fuel economy. Lighter weight valve train components permit the use of lower spring loads, thus reducing friction and increasing fuel economy. Camshaft friction measurements made on a typical small displacement engine indicate that a twoto-four percent increase in fuel economy can be achieved. Valve train components are, however, subject to a severe operating environment, including elevated temperatures, sliding wear and high mechanical loads. This paper discusses the details of alloy and heat treatment selection for optimizing valve performance. When properly manufactured, titanium valves have been shown to withstand very stringent durability testing, indicating the technical feasibility of this approach to fuel economy improvement.

  16. Photovoltaic System Performance

    Energy Science and Technology Software Center (ESTSC)

    1989-09-25

    PVFORM4.0 is used to design a photovoltaic (PV) system using a set of design parameters which optimize the system's economic potential for the proposed location and the expected operating conditions. PVFORM3.3 has been used to determine PV system size and optimum mounting configuration. The anticipated electrical load determines the system size and the weather and the mounting configuration affect the system output. PVFORM4.0 uses program-supplied default values or their user-supplied equivalents for each of amore » large number of parameters describing the system and time-series data describing the environment to perform a series of hourly calculations to simulate the physical (photovoltaic) performance of a PV system for a one-year period. These iterative calculations sample the performance of the PV system throughout a simulated 365-day year of system operation. Within any simulated day on which system performance is sampled, the calculations are done hourly. The number of days sampled and the interval between them is determined by an input parameter. The results of these calculations are summarized on a monthly basis in output tables and an optional plot file. The program is applicable to grid interactive or stand-alone flat-plate systems. The grid interactive system is assumed to use power purchased from a local utility to supply that portion of the load not met by the simulated PV array. If the array produces more energy than can be consumed by the load, the excess energy is assumed to be sold back to the utility at a constant energy sellback price. If a stand-alone system is being modeled, the program assumes that all energy produced by the simulated PV array is first applied to the external load, and any excess is then used to charge the battery bank. Energy not consumed by the load or the batteries is considered to be wasted.« less

  17. HIDEC F-15 adaptive engine control system flight test results

    NASA Technical Reports Server (NTRS)

    Smolka, James W.

    1987-01-01

    NASA-Ames' Highly Integrated Digital Electronic Control (HIDEC) flight test program aims to develop fully integrated airframe, propulsion, and flight control systems. The HIDEC F-15 adaptive engine control system flight test program has demonstrated that significant performance improvements are obtainable through the retention of stall-free engine operation throughout the aircraft flight and maneuver envelopes. The greatest thrust increase was projected for the medium-to-high altitude flight regime at subsonic speed which is of such importance to air combat. Adaptive engine control systems such as the HIDEC F-15's can be used to upgrade the performance of existing aircraft without resort to expensive reengining programs.

  18. Adjusting the specificity of an engine map based on the sensitivity of an engine control parameter relative to a performance variable

    DOEpatents

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2014-10-28

    Methods and systems for engine control optimization are provided. A first and a second operating condition of a vehicle engine are detected. An initial value is identified for a first and a second engine control parameter corresponding to a combination of the detected operating conditions according to a first and a second engine map look-up table. The initial values for the engine control parameters are adjusted based on a detected engine performance variable to cause the engine performance variable to approach a target value. A first and a second sensitivity of the engine performance variable are determined in response to changes in the engine control parameters. The first engine map look-up table is adjusted when the first sensitivity is greater than a threshold, and the second engine map look-up table is adjusted when the second sensitivity is greater than a threshold.

  19. Energy efficient engine: Propulsion system-aircraft integration evaluation

    NASA Technical Reports Server (NTRS)

    Owens, R. E.

    1979-01-01

    Flight performance and operating economics of future commercial transports utilizing the energy efficient engine were assessed as well as the probability of meeting NASA's goals for TSFC, DOC, noise, and emissions. Results of the initial propulsion systems aircraft integration evaluation presented include estimates of engine performance, predictions of fuel burns, operating costs of the flight propulsion system installed in seven selected advanced study commercial transports, estimates of noise and emissions, considerations of thrust growth, and the achievement-probability analysis.

  20. Analytical concepts for health management systems of liquid rocket engines

    NASA Technical Reports Server (NTRS)

    Williams, Richard; Tulpule, Sharayu; Hawman, Michael

    1990-01-01

    Substantial improvement in health management systems performance can be realized by implementing advanced analytical methods of processing existing liquid rocket engine sensor data. In this paper, such techniques ranging from time series analysis to multisensor pattern recognition to expert systems to fault isolation models are examined and contrasted. The performance of several of these methods is evaluated using data from test firings of the Space Shuttle main engines.

  1. The Case for Distributed Engine Control in Turbo-Shaft Engine Systems

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Paluszewski, Paul J.; Storey, William; Smith, Bert J.

    2009-01-01

    The turbo-shaft engine is an important propulsion system used to power vehicles on land, sea, and in the air. As the power plant for many high performance helicopters, the characteristics of the engine and control are critical to proper vehicle operation as well as being the main determinant to overall vehicle performance. When applied to vertical flight, important distinctions exist in the turbo-shaft engine control system due to the high degree of dynamic coupling between the engine and airframe and the affect on vehicle handling characteristics. In this study, the impact of engine control system architecture is explored relative to engine performance, weight, reliability, safety, and overall cost. Comparison of the impact of architecture on these metrics is investigated as the control system is modified from a legacy centralized structure to a more distributed configuration. A composite strawman system which is typical of turbo-shaft engines in the 1000 to 2000 hp class is described and used for comparison. The overall benefits of these changes to control system architecture are assessed. The availability of supporting technologies to achieve this evolution is also discussed.

  2. Photovoltaic lighting system performance

    SciTech Connect

    Harrington, S.R.; Hund, T.D.

    1996-06-01

    The performance of 21 PV-powered low pressure sodium lighting systems on a multi-use has been documented in this paper. Specific areas for evaluation include the vandal resistant PV modules, constant voltage and on/off PV charge controllers, flooded deep-cycle lead-antimony and valve regulated lead-acid (VLRA) gel batteries, and low pressure sodium ballasts and lights. The PV lighting system maintenance intervals and lessons learned have been documented over the past 2.5 years. The above performance data has shown that with careful hardware selection, installation, and maintenance intervals the PV lighting systems will operate reliably.

  3. Relations between information system engineering and software engineering

    NASA Technical Reports Server (NTRS)

    Callender, E. D.; Hartsough, C.; Morris, R. V.

    1981-01-01

    This paper examines some of the relations between information system engineering and software engineering. A model for the development process of an information system is presented that focuses on problems common to both disciplines. The concepts of complexity, multiplicity of view, distortion in communication, and concurrency and iteration in implementation are treated. A set of design constructs for the description of an information system is presented. The role of project management is treated. The issue of how to characterize requirements analysis is answered by making it a design activity from the point of view of a user of the product system.

  4. A conceptual design tool for RBCC engine performance analysis

    NASA Astrophysics Data System (ADS)

    Olds, John R.; Saks, Greg

    1997-01-01

    Future reusable launch vehicles will depend on new propulsion technologies to lower system operational costs while maintaining adequate performance. Recently, a number of vehicle systems utilizing rocket-based combined-cycle (RBCC) propulsion have been proposed as possible low-cost space launch solutions. Vehicles using RBCC propulsion have the potential to combine the best aspects of airbreathing propulsion (high average Isp) with the best aspects of rocket propulsion (high propellant bulk density and engine T/W). Proper conceptual assessment of each proposed vehicle will require computer-based tools that allow for quick and cheap, yet sufficiently accurate disciplinary analyses. At Georgia Tech, a spreadsheet-based tool has been developed that uses quasi-1D flow analysis with component efficiencies to parametrically model RBCC engine performance in ejector, fan-ramjet, ramjet and pure rocket modes. The technique is similar to an earlier RBCC modeling technique developed by the Marquardt Corporation in the mid-1960's. For a given sea-level static thrust requirement, the current tool generates engine weight and size data, as well as Isp and thrust data vs. altitude and Mach number. The latter is output in tabular form for use in a trajectory optimization program. This paper reviews the current state of the RBCC analysis tool and the effort to upgrade it from a Microsoft Excel spreadsheet to a design-oriented UNIX program in C suitable for integration into a multidisciplinary design optimization (MDO) framework.

  5. A conceptual design tool for RBCC engine performance analysis

    SciTech Connect

    Olds, J.R.; Saks, G.

    1997-01-01

    Future reusable launch vehicles will depend on new propulsion technologies to lower system operational costs while maintaining adequate performance. Recently, a number of vehicle systems utilizing rocket-based combined-cycle (RBCC) propulsion have been proposed as possible low-cost space launch solutions. Vehicles using RBCC propulsion have the potential to combine the best aspects of airbreathing propulsion (high average Isp) with the best aspects of rocket propulsion (high propellant bulk density and engine T/W). Proper conceptual assessment of each proposed vehicle will require computer-based tools that allow for quick and cheap, yet sufficiently accurate disciplinary analyses. At Georgia Tech, a spreadsheet-based tool has been developed that uses quasi-1D flow analysis with component efficiencies to parametrically model RBCC engine performance in ejector, fan-ramjet, ramjet and pure rocket modes. The technique is similar to an earlier RBCC modeling technique developed by the Marquardt Corporation in the mid-1960{close_quote}s. For a given sea-level static thrust requirement, the current tool generates engine weight and size data, as well as Isp and thrust data vs. altitude and Mach number. The latter is output in tabular form for use in a trajectory optimization program. This paper reviews the current state of the RBCC analysis tool and the effort to upgrade it from a Microsoft Excel spreadsheet to a design-oriented UNIX program in C suitable for integration into a multidisciplinary design optimization (MDO) framework. {copyright} {ital 1997 American Institute of Physics.}

  6. The Art and Science of Systems Engineering

    NASA Technical Reports Server (NTRS)

    Singer, Christopher E.

    2009-01-01

    The National Aeronautics and Space Administration (NASA) was established in 1958, and its Marshall Space Flight Center was founded in 1960, as space-related work was transferred from the Army Ballistic Missile Agency at Redstone Arsenal, where Marshall is located. With this heritage, Marshall contributes almost 50 years of systems engineering experience with human-rated launch vehicles and scientific spacecraft to fulfill NASA's mission exploration and discovery. These complex, highly specialized systems have provided vital platforms for expanding the knowledge base about Earth, the solar system, and cosmos; developing new technologies that also benefit life on Earth; and opening new frontiers for America's strategic space goals. From Mercury and Gemini, to Apollo and the Space Shuttle, Marshall's systems engineering expertise is an unsurpassed foundational competency for NASA and the nation. Current assignments comprise managing Space Shuttle Propulsion systems; developing environmental control and life support systems and coordinating science operations on the International Space Station; and a number of exploration-related responsibilities. These include managing and performing science missions, such as the Lunar Crater Observation and Sensing Satellite and the Lunar Reconnaissance Orbiter slated to launch for the Moon in April 2009, to developing the Ares I crew launch vehicle upper stage and integrating the vehicle stack in house, as well as designing the Ares V cargo launch vehicle and contributing to the development of the Altair Lunar Lander and an International Lunar Network with communications nodes and other infrastructure.

  7. Engineering development of coal-fired high performance power systems, Phase II and Phase III. Quarter progress report, April 1, 1996--June 30, 1996

    SciTech Connect

    1996-11-01

    Work is presented on the development of a coal-fired high performance power generation system by the year 2000. This report describes the design of the air heater, duct heater, system controls, slag viscosity, and design of a quench zone.

  8. Performance of Several Combustion Chambers Designed for Aircraft Oil Engines

    NASA Technical Reports Server (NTRS)

    Joachim, William F; Kemper, Carlton

    1928-01-01

    Several investigations have been made on single-cylinder test engines to determine the performance characteristics of four types of combustion chambers designed for aircraft oil engines. Two of the combustion chambers studied were bulb-type precombustion chambers, the connecting orifice of one having been designed to produce high turbulence by tangential air flow in both the precombustion chamber and the cylinder. The other two were integral combustion chambers, one being dome-shaped and the other pent-roof shaped. The injection systems used included cam and eccentric driven fuel pumps, and diaphragm and spring-loaded fuel-injection valves. A diaphragm type maximum cylinder pressure indicator was used in part of these investigations with which the cylinder pressures were controlled to definite valves. The performance of the engines when equipped with each of the combustion chambers is discussed. The best performance for the tests reported was obtained with a bulb-type combustion chamber designed to give a high degree of turbulence within the bulb and cylinder. (author)

  9. Earth Systems Science and Engineering

    SciTech Connect

    Rotman, D A

    2006-02-21

    Providing the essential energy and water systems to support human needs while understanding and addressing their environmental consequences is a watershed problem for the 21st century. The LLNL Earth System Science and Engineering Program seeks to provide the scientific understanding and technological expertise to help provide solutions at both global and regional scales. Our work is highly collaborative with universities, laboratories and industrial partners across the world and involves observational data, laboratory experiments, and numerical simulations. The energy systems we have enjoyed for the last 100 years have resulted in the advanced standard of living in the developed world and a major emerging problem with climate change. Now we face a simultaneous realization that our reliance on fossil fuels is a source of conflict and economic disruption as well as causing potentially abrupt, even catastrophic global climate change. The climate and energy problem is perhaps the greatest challenge ever faced by mankind. Fossil fuel remains the least expensive and most available source of energy and the basis of our economy. The use of fossil fuels, especially over the last 100 years has led to a 30% increase in CO{sub 2} in the atmosphere. The problem is growing. The population of the Earth will increase by several billion people in the next 50 years. If economic growth is to continue, the demand for energy is estimated to approximately double in the next 50 years so that we will need approximately 10 TW more energy than the 15 TW we use now. Much of this demand will come from the developing world where most of the population growth will occur and where advanced energy technology is not generally used. The problem affects and is affected by a complex system of systems. The climate and energy problem will affect resources, social structure and the probability of increased conflict. No one person, no one nation, no one technology can solve the problem. There is no

  10. Template for Systems Engineering Tools Trade Study

    NASA Technical Reports Server (NTRS)

    Bailey, Michelle D.

    2005-01-01

    A discussion of Systems Engineering tools brings out numerous preferences and reactions regarding tools of choice as well as the functions those tools are to perform. A recent study of Systems Engineering Tools for a new Program illustrated the need for a generic template for use by new Programs or Projects to determine the toolset appropriate for their use. This paper will provide the guidelines new initiatives can follow and tailor to their specific needs, to enable them to make their choice of tools in an efficient and informed manner. Clearly, those who perform purely technical functions will need different tools than those who perform purely systems engineering functions. And, everyone has tools they are comfortable with. That degree of comfort is frequently the deciding factor in tools choice rather than an objective study of all criteria and weighting factors. This paper strives to produce a comprehensive list of criteria for selection with suggestions for weighting factors based on a number of assumptions regarding the given Program or Project. In addition, any given Program will begin with assumptions for its toolset based on Program size, tool cost, user base and technical needs. In providing a template for tool selection, this paper will guide the reader through assumptions based on Program need; decision criteria; potential weighting factors; the need for a compilation of available tools; the importance of tool demonstrations; and finally a down selection of tools. While specific vendors cannot be mentioned in this work, it is expected that this template could serve other Programs in the formulation phase by alleviating the trade study process of some of its subjectivity.

  11. Performance Benefits for Wave Rotor-Topped Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    Jones, Scott M.; Welch, Gerard E.

    1996-01-01

    The benefits of wave rotor-topping in turboshaft engines, subsonic high-bypass turbofan engines, auxiliary power units, and ground power units are evaluated. The thermodynamic cycle performance is modeled using a one-dimensional steady-state code; wave rotor performance is modeled using one-dimensional design/analysis codes. Design and off-design engine performance is calculated for baseline engines and wave rotor-topped engines, where the wave rotor acts as a high pressure spool. The wave rotor-enhanced engines are shown to have benefits in specific power and specific fuel flow over the baseline engines without increasing turbine inlet temperature. The off-design steady-state behavior of a wave rotor-topped engine is shown to be similar to a conventional engine. Mission studies are performed to quantify aircraft performance benefits for various wave rotor cycle and weight parameters. Gas turbine engine cycles most likely to benefit from wave rotor-topping are identified. Issues of practical integration and the corresponding technical challenges with various engine types are discussed.

  12. Developing Systems Engineering Skills Through NASA Summer Intern Project

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul; Barritt, Brian; Golden, Bert; Knoblock, Eric; Matthews, Seth; Warner, Joe

    2010-01-01

    During the Formulation phases of the NASA Project Life Cycle, communication systems engineers are responsible for designing space communication links and analyzing their performance to ensure that the proposed communication architecture is capable of satisfying high-level mission requirements. Senior engineers with extensive experience in communications systems perform these activities. However, the increasing complexity of space systems coupled with the current shortage of communications systems engineers has led to an urgent need for expedited training of new systems engineers. A pilot program, in which college-bound high school and undergraduate students studying various engineering disciplines are immersed in NASA s systems engineering practices, was conceived out of this need. This rapid summerlong training approach is feasible because of the availability of advanced software and technology tools and the students inherent ability to operate such tools. During this pilot internship program, a team of college-level and recently-hired engineers configured and utilized various software applications in the design and analysis of communication links for a plausible lunar sortie mission. The approach taken was to first design the direct-to-Earth communication links for the lunar mission elements, then to design the links between lunar surface and lunar orbital elements. Based on the data obtained from these software applications, an integrated communication system design was realized and the students gained valuable systems engineering knowledge. This paper describes this approach to rapidly training college-bound high school and undergraduate engineering students from various disciplines in NASA s systems engineering practices and tools. A summary of the potential use of NASA s emerging systems engineering internship program in broader applications is also described.

  13. Engine Structures Modeling Software System (ESMOSS)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Engine Structures Modeling Software System (ESMOSS) is the development of a specialized software system for the construction of geometric descriptive and discrete analytical models of engine parts, components, and substructures which can be transferred to finite element analysis programs such as NASTRAN. The NASA Lewis Engine Structures Program is concerned with the development of technology for the rational structural design and analysis of advanced gas turbine engines with emphasis on advanced structural analysis, structural dynamics, structural aspects of aeroelasticity, and life prediction. Fundamental and common to all of these developments is the need for geometric and analytical model descriptions at various engine assembly levels which are generated using ESMOSS.

  14. Methane fueled engine performance and emissions characteristics

    SciTech Connect

    Swain, M.R.; Adt, R.R.; Bedsworth, K.; Maxwell, R.; Pappas, J.M.; Swain, M.N.

    1983-08-01

    A 1983 Ford 3.8 liter V-6 engine was fueled with methane and tested on an engine dynamometer in order to begin to generate a data base that could be used to estimate emission levels and fuel economy for a driving cycle from a 3-point mini map method. The results showed that, with the proper control of pertinent engine variables, the engine would probably meet the current State of California Emission Standards that have been formulated to account for methane as an unburned hydrocarbon, without having to resort to a catalytic converter, and with Joules fuel consumption comparable, if not better than that for a gasoline-fueled vehicle. Unburned fuel in the exhaust was found to be comprised of between 87 and 96% methane. MBTH total aldehyde emissions were found to vary between 27 and 67 molar ppm.

  15. Fading channel issues in system engineering

    NASA Astrophysics Data System (ADS)

    Stein, Seymour

    1987-02-01

    The character of multipath-induced propagational fading is reviewed, along with the interpretations underlying use of the Rayleigh fading model to describe the process statistics. The relationship between this model and contemporary laboratory fading simulators is also outlined. The effects of the fading upon data communications are described, along with the techniques of modulation, diversity, coding, and adaptive equalization used in modern modem designs for operation over such channels. Finally, the system engineering problems are discussed of attempting to provide quantitative estimates of long-term link or network performance that takes into account the longer term channel variabilities.

  16. ATK Launch Systems Engineering NASA Programs Engineering Examples

    NASA Technical Reports Server (NTRS)

    Richardson, David

    2007-01-01

    This presentation provides an overview of the work done at ATK Launch Systems with and indication of how engineering knowledge can be applied to several real world problems. All material in the presentation has been screened to meet ITAR restrictions. The information provided is a compilation of general engineering knowledge and material available in the public domain. The presentation provides an overview of ATK Launch Systems and NASA programs. Some discussion is provided about the types of engineering conducted at the Promontory plant with added detail about RSRM nozzle engineering. Some brief examples of examples of nozzle technical issues with regard to adhesives and phenolics are shared. These technical issue discussions are based on material available in the public domain.

  17. Software Engineering Laboratory Ada performance study: Results and implications

    NASA Technical Reports Server (NTRS)

    Booth, Eric W.; Stark, Michael E.

    1992-01-01

    The SEL is an organization sponsored by NASA/GSFC to investigate the effectiveness of software engineering technologies applied to the development of applications software. The SEL was created in 1977 and has three organizational members: NASA/GSFC, Systems Development Branch; The University of Maryland, Computer Sciences Department; and Computer Sciences Corporation, Systems Development Operation. The goals of the SEL are as follows: (1) to understand the software development process in the GSFC environments; (2) to measure the effect of various methodologies, tools, and models on this process; and (3) to identify and then to apply successful development practices. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that include the Ada Performance Study Report. This paper describes the background of Ada in the Flight Dynamics Division (FDD), the objectives and scope of the Ada Performance Study, the measurement approach used, the performance tests performed, the major test results, and the implications for future FDD Ada development efforts.

  18. The Control System for the X-33 Linear Aerospike Engine

    NASA Technical Reports Server (NTRS)

    Jackson, Jerry E.; Espenschied, Erich; Klop, Jeffrey

    1998-01-01

    The linear aerospike engine is being developed for single-stage -to-orbit (SSTO) applications. The primary advantages of a linear aerospike engine over a conventional bell nozzle engine include altitude compensation, which provides enhanced performance, and lower vehicle weight resulting from the integration of the engine into the vehicle structure. A feature of this integration is the ability to provide thrust vector control (TVC) by differential throttling of the engine combustion elements, rather than the more conventional approach of gimballing the entire engine. An analysis of the X-33 flight trajectories has shown that it is necessary to provide +/- 15% roll, pitch and yaw TVC authority with an optional capability of +/- 30% pitch at select times during the mission. The TVC performance requirements for X-33 engine became a major driver in the design of the engine control system. The thrust level of the X-33 engine as well as the amount of TVC are managed by a control system which consists of electronic, instrumentation, propellant valves, electro-mechanical actuators, spark igniters, and harnesses. The engine control system is responsible for the thrust control, mixture ratio control, thrust vector control, engine health monitoring, and communication to the vehicle during all operational modes of the engine (checkout, pre-start, start, main-stage, shutdown and post shutdown). The methodology for thrust vector control, the health monitoring approach which includes failure detection, isolation, and response, and the basic control system design are the topic of this paper. As an additional point of interest a brief description of the X-33 engine system will be included in this paper.

  19. Distributed control system for turbine engines

    SciTech Connect

    Shaffer, P.L.

    1999-01-01

    A distributed control system (DCS) for a turbine engine has been demonstrated and tested, consisting of prototype electronic interface units (EIUs) connected to data and power busses. In the DCS, a central control computer communicated with smart sensors and smart actuators via a 2.5 megabit/sec digital data bus, using the Fieldbus protocol. Power was distributed to the smart devices as 100 kHz 100V peak AC, allowing light, simple power converters at each smart device. All smart sensors, smart actuators, and cables were dual redundant. The smart actuators received position demand from the central control computer, exchanged data between channels to provide local redundancy management, closed the position loop locally, and reported actuator position to the central controller. Smart sensors converted sensed signals to digital values in engineering units, and performed local built-in tests. Testing of the DCS was done in a closed-loop simulation with an engine model. Frequency response of the DCS was almost identical with the conventional system.

  20. A Rocket Engine Design Expert System

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth J.

    1989-01-01

    The overall structure and capabilities of an expert system designed to evaluate rocket engine performance are described. The expert system incorporates a JANNAF standard reference computer code to determine rocket engine performance and a state of the art finite element computer code to calculate the interactions between propellant injection, energy release in the combustion chamber, and regenerative cooling heat transfer. Rule-of-thumb heuristics were incorporated for the H2-O2 coaxial injector design, including a minimum gap size constraint on the total number of injector elements. One dimensional equilibrium chemistry was used in the energy release analysis of the combustion chamber. A 3-D conduction and/or 1-D advection analysis is used to predict heat transfer and coolant channel wall temperature distributions, in addition to coolant temperature and pressure drop. Inputting values to describe the geometry and state properties of the entire system is done directly from the computer keyboard. Graphical display of all output results from the computer code analyses is facilitated by menu selection of up to five dependent variables per plot.

  1. A rocket engine design expert system

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth J.

    1989-01-01

    The overall structure and capabilities of an expert system designed to evaluate rocket engine performance are described. The expert system incorporates a JANNAF standard reference computer code to determine rocket engine performance and a state-of-the-art finite element computer code to calculate the interactions between propellant injection, energy release in the combustion chamber, and regenerative cooling heat transfer. Rule-of-thumb heuristics were incorporated for the hydrogen-oxygen coaxial injector design, including a minimum gap size constraint on the total number of injector elements. One-dimensional equilibrium chemistry was employed in the energy release analysis of the combustion chamber and three-dimensional finite-difference analysis of the regenerative cooling channels was used to calculate the pressure drop along the channels and the coolant temperature as it exits the coolant circuit. Inputting values to describe the geometry and state properties of the entire system is done directly from the computer keyboard. Graphical display of all output results from the computer code analyses is facilitated by menu selection of up to five dependent variables per plot.

  2. Energy efficient engine core design and performance report. Report, January 1978-December 1982

    SciTech Connect

    Stearns, E.M.

    1982-12-01

    The Energy Efficient Engine (E3) is a NASA program to develop fuel saving technology for future large transport aircraft engines. Testing of the General Electric E3 core showed that the core component performance and core system performance necessary to meet the program goals can be achieved. The E3 core design and test results are described.

  3. System Engineering of Autonomous Space Vehicles

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Johnson, Stephen B.; Trevino, Luis

    2014-01-01

    Human exploration of the solar system requires fully autonomous systems when travelling more than 5 light minutes from Earth. This autonomy is necessary to manage a large, complex spacecraft with limited crew members and skills available. The communication latency requires the vehicle to deal with events with only limited crew interaction in most cases. The engineering of these systems requires an extensive knowledge of the spacecraft systems, information theory, and autonomous algorithm characteristics. The characteristics of the spacecraft systems must be matched with the autonomous algorithm characteristics to reliably monitor and control the system. This presents a large system engineering problem. Recent work on product-focused, elegant system engineering will be applied to this application, looking at the full autonomy stack, the matching of autonomous systems to spacecraft systems, and the integration of different types of algorithms. Each of these areas will be outlined and a general approach defined for system engineering to provide the optimal solution to the given application context.

  4. Operator Performance Support System (OPSS)

    NASA Technical Reports Server (NTRS)

    Conklin, Marlen Z.

    1993-01-01

    In the complex and fast reaction world of military operations, present technologies, combined with tactical situations, have flooded the operator with assorted information that he is expected to process instantly. As technologies progress, this flow of data and information have both guided and overwhelmed the operator. However, the technologies that have confounded many operators today can be used to assist him -- thus the Operator Performance Support Team. In this paper we propose an operator support station that incorporates the elements of Video and Image Databases, productivity Software, Interactive Computer Based Training, Hypertext/Hypermedia Databases, Expert Programs, and Human Factors Engineering. The Operator Performance Support System will provide the operator with an integrating on-line information/knowledge system that will guide expert or novice to correct systems operations. Although the OPSS is being developed for the Navy, the performance of the workforce in today's competitive industry is of major concern. The concepts presented in this paper which address ASW systems software design issues are also directly applicable to industry. the OPSS will propose practical applications in how to more closely align the relationships between technical knowledge and equipment operator performance.

  5. Performance characteristics of brush seals for limited-life engines

    SciTech Connect

    Chupp, R.E. ); Dowler, C.A. )

    1993-04-01

    Brush seals are potential replacements for air-to-air labyrinth seals in gas turbine engines. An investigation has been conducted to determine the performance characteristics of brush seals for application in limited-life gas turbine engines. An elevated temperature, rotating test rig was designed and built to test labyrinth and brush seals in simulated subsonic and supersonic engine conditions. Results from initial tests for subsonic applications demonstrated that brush seals exhibit appreciably lower leakage compared to labyrinth seals, and thus offer significant engine performance improvements. Performance results have been obtained showing the effect of various brush seal parameters, including: initial interference, backplate gap, and multiple brush seals in series.

  6. System Performance Characterization

    SciTech Connect

    van Dam, M A

    2004-05-26

    Characterizing an adaptive optics (AO) system refers to understanding its performance and limitations. The goal of an AO system is to correct wavefront aberrations. The uncorrected aberrations, called the residual errors and referred to in what follows simply as the errors, degrade the image quality in the science camera. Understanding the source of these errors is a great aid in designing an AO system and optimizing its performance. This chapter explains how to estimate the wavefront error terms and the relationship between the wavefront error and the degradation of the image. The analysis deals with the particular case of a HartmannShack wavefront sensor (WFS) and a continuous deformable mirror (DM), although the principles involved can be applied to any AO system.

  7. Advancing Systems Engineering Excellence: The Marshall Systems Engineering Leadership Development Program

    NASA Technical Reports Server (NTRS)

    Hall, Philip; Whitfield, Susan

    2011-01-01

    As NASA undertakes increasingly complex projects, the need for expert systems engineers and leaders in systems engineering is becoming more pronounced. As a result of this issue, the Agency has undertaken an initiative to develop more systems engineering leaders through its Systems Engineering Leadership Development Program; however, the NASA Office of the Chief Engineer has also called on the field Centers to develop mechanisms to strengthen their expertise in systems engineering locally. In response to this call, Marshall Space Flight Center (MSFC) has developed a comprehensive development program for aspiring systems engineers and systems engineering leaders. This presentation will summarize the two-level program, which consists of a combination of training courses and on-the-job, developmental training assignments at the Center to help develop stronger expertise in systems engineering and technical leadership. In addition, it will focus on the success the program has had in its pilot year. The program hosted a formal kickoff event for Level I on October 13, 2009. The first class includes 42 participants from across MSFC and Michoud Assembly Facility (MAF). A formal call for Level II is forthcoming. With the new Agency focus on research and development of new technologies, having a strong pool of well-trained systems engineers is becoming increasingly more critical. Programs such as the Marshall Systems Engineering Leadership Development Program, as well as those developed at other Centers, help ensure that there is an upcoming generation of trained systems engineers and systems engineering leaders to meet future design challenges.

  8. High performance solar Stirling system

    NASA Technical Reports Server (NTRS)

    Stearns, J. W.; Haglund, R.

    1981-01-01

    A full-scale Dish-Stirling system experiment, at a power level of 25 kWe, has been tested during 1981 on the Test Bed Concentrator No. 2 at the Parabolic Dish Test Site, Edwards, CA. Test components, designed and developed primarily by industrial contractors for the Department of Energy, include an advanced Stirling engine driving an induction alternator, a directly-coupled solar receiver with a natural gas combustor for hybrid operation and a breadboard control system based on a programmable controller and standard utility substation components. The experiment demonstrated practicality of the solar Stirling application and high system performance into a utility grid. This paper describes the design and its functions, and the test results obtained.

  9. HPT Clearance Control: Intelligent Engine Systems-Phase 1

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The following work has been completed to satisfy the Phase I Deliverables for the "HPT Clearance Control" project under NASA GRC's "Intelligent Engine Systems" program: (1) Need for the development of an advanced HPT ACC system has been very clearly laid out, (2) Several existing and potential clearance control systems have been reviewed, (3) A scorecard has been developed to document the system, performance (fuel burn, range, payload, etc.), thermal, and mechanical characteristics of the existing clearance control systems, (4) Engine size and flight cycle selection for the advanced HPT ACC system has been reviewed with "large engine"/"long range mission" combination showing the most benefit, (5) A scoring criteria has been developed to tie together performance parameters for an objective, data driven comparison of competing systems, and (6) The existing HPT ACC systems have been scored based on this scoring system.

  10. Nissan V6 3. 0 litre, 4-cam 24-valve high performance engine

    SciTech Connect

    Nishimura, S.; Fukuhara, T.; Teramoto, M.

    1987-01-01

    Nissan has developed a new VG30DE engine of a high performance version of VG SOHC engine series. It is a 3.0 liter 60/sup 0/ V6 engine, having 4 camshafts, 24 valves, and many advanced technologies. It has developed for LEOPARD sport sedan, FAIRLADY Z sport and MID-4 sport, and introduced to the Japanese domestic market in 1986. A major development target was to achieve high engine performance that fully matches to driver's expectations. To attain this objective, the engine incorporates a number of advanced technologies, such as a cross-flow cooling system, which utilizes a water gallery for the cylinder block and aluminum cylinder heads, ECCS (Electronic Concentrated engine Control System), an individual cylinder knocking control system by cylinder pressure sensors, NVCS (Nissan Valve Timing Control System).

  11. Designing Liquid Rocket Engine Injectors for Performance, Stability, and Cost

    NASA Technical Reports Server (NTRS)

    Westra, Douglas G.; West, Jeffrey S.

    2014-01-01

    NASA is developing the Space Launch System (SLS) for crewed exploration missions beyond low Earth orbit. Marshall Space Flight Center (MSFC) is designing rocket engines for the SLS Advanced Booster (AB) concepts being developed to replace the Shuttle-derived solid rocket boosters. One AB concept uses large, Rocket-Propellant (RP)-fueled engines that pose significant design challenges. The injectors for these engines require high performance and stable operation while still meeting aggressive cost reduction goals for access to space. Historically, combustion stability problems have been a critical issue for such injector designs. Traditional, empirical injector design tools and methodologies, however, lack the ability to reliably predict complex injector dynamics that often lead to combustion stability. Reliance on these tools alone would likely result in an unaffordable test-fail-fix cycle for injector development. Recently at MSFC, a massively parallel computational fluid dynamics (CFD) program was successfully applied in the SLS AB injector design process. High-fidelity reacting flow simulations were conducted for both single-element and seven-element representations of the full-scale injector. Data from the CFD simulations was then used to significantly augment and improve the empirical design tools, resulting in a high-performance, stable injector design.

  12. STEP-AIRSEDS System Engineering Support

    NASA Technical Reports Server (NTRS)

    Rowell, Tom; Taliaferro, Lanny

    2001-01-01

    This report summarizes and highlights the activities in support of the Space Transportation using Electrodynamic Propulsion Atmospheric Ionospheric Research Small Expendable Deployer Satellite (STEP-AIRSEDS) Project for the period of May 16, 2000 through September 28, 2001. The Alpha Technology, Inc. was tasked to provide support to the MSFC (Marshall Space Flight Center) in requirements development and in verification activities. Specifically, the Alpha Technology, Inc. task was to: (1) develop and maintain the STEP-AIRSEDS Project System Requirements Database; (2) develop and maintain the STEP-AIRSEDS requirements verification definition and planning support database; (3) perform requirements flow down analysis of STEP-AIRSEDS Project System Requirements to TMTC (The Michigan Technic Corporation) Level IV Requirements; (4) provide system engineering guidance to the Project as needed; (5) provide guidance to TMTC in preparation of Level IV Requirements; and (6) provide support to STEP-AIRSEDS meetings, reviews, and telecons as needed.

  13. An interactive preprocessor for the NASA engine performance program

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.; Plencner, Robert M.

    1992-01-01

    The Simplified NEPP Automated Preprocessor (SNAP), which is written to aid in the preparation of input data files for the NASA Engine Performance Program (NEPP), is described. Specifically, SNAP is a software package on the Virtual Machine operating system that prompts the NEPP user for input information via a series of menus. The data collected from these menus are assimilated into an input file suitable for the running of NEPP. SNAP acts as a user-friendly preprocessing interface for NEPP. This serves as an introduction to the SNAP software, a user's manual, a description of the program logic, and a maintenance manual for future modifications to the software.

  14. High performance systems

    SciTech Connect

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  15. Effects of compositional changes on the performance of a thermal barrier coating system. [yttria-stabilized zirconia coatings on gas turbine engine blades

    NASA Technical Reports Server (NTRS)

    Stecura, S.

    1978-01-01

    Currently proposed thermal barrier systems for aircraft gas turbine engines consist of NiCrAlY bond coating covered with an insulating oxide layer of yttria-stabilized zirconia. The effect of yttrium concentration (from 0.15 to 1.08 w/o) in the bond coating and the yttria concentration (4 to 24.4 w/o) in the oxide layer were evaluated. Furnace, natural gas-oxygen torch, and Mach 1.0 burner rig cyclic tests on solid specimens and air-cooled blades were used to identify trends in coating behavior. Results indicate that the combinations of yttrium levels between 0.15 - 0.35 w/o in the bond coating and the yttria concentration between 6 - 8 w/o in the zirconium oxide layer were the most adherent and resistant to high temperature cyclic exposure.

  16. Metaconcrete: Engineered aggregates for enhanced dynamic performance

    NASA Astrophysics Data System (ADS)

    Mitchell, Stephanie J.

    This work presents the development and investigation of a new type of concrete for the attenuation of waves induced by dynamic excitation. Recent progress in the field of metamaterials science has led to a range of novel composites which display unusual properties when interacting with electromagnetic, acoustic, and elastic waves. A new structural metamaterial with enhanced properties for dynamic loading applications is presented, which is named metaconcrete. In this new composite material the standard stone and gravel aggregates of regular concrete are replaced with spherical engineered inclusions. Each metaconcrete aggregate has a layered structure, consisting of a heavy core and a thin compliant outer coating. This structure allows for resonance at or near the eigenfrequencies of the inclusions, and the aggregates can be tuned so that resonant oscillations will be activated by particular frequencies of an applied dynamic loading. The activation of resonance within the aggregates causes the overall system to exhibit negative effective mass, which leads to attenuation of the applied wave motion. To investigate the behavior of metaconcrete slabs under a variety of different loading conditions a finite element slab model containing a periodic array of aggregates is utilized. The frequency dependent nature of metaconcrete is investigated by considering the transmission of wave energy through a slab, which indicates the presence of large attenuation bands near the resonant frequencies of the aggregates. Applying a blast wave loading to both an elastic slab and a slab model that incorporates the fracture characteristics of the mortar matrix reveals that a significant portion of the supplied energy can be absorbed by aggregates which are activated by the chosen blast wave profile. The transfer of energy from the mortar matrix to the metaconcrete aggregates leads to a significant reduction in the maximum longitudinal stress, greatly improving the ability of the material

  17. Design study of RL10 derivatives. Volume 2: Engine design characteristics, appendices. [development of rocket engine for application to space tug propulsion system

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Calculations, curves, and substantiating data which support the engine design characteristics of the RL-10 engines are presented. A description of the RL-10 ignition system is provided. The performance calculations of the RL-10 derivative engines and the performance results obtained are reported. The computer simulations used to establish the control system requirements and to define the engine transient characteristics are included.

  18. System Study for Axial Vane Engine Technology

    NASA Technical Reports Server (NTRS)

    Badley, Patrick R.; Smith, Michael R.; Gould, Cedric O.

    2008-01-01

    The purpose of this engine feasibility study was to determine the benefits that can be achieved by incorporating positive displacement axial vane compression and expansion stages into high bypass turbofan engines. These positive-displacement stages would replace some or all of the conventional compressor and turbine stages in the turbine engine, but not the fan. The study considered combustion occurring internal to an axial vane component (i.e., Diesel engine replacing the standard turbine engine combustor, burner, and turbine); and external continuous flow combustion with an axial vane compressor and an axial vane turbine replacing conventional compressor and turbine systems.

  19. The JT8D and JT9D engine component improvement: Performance improvement program

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1982-01-01

    The NASA sponsored Engine Component Improvement - Performance Improvement Program at Pratt & Whitney Aircraft advanced the state of the art of thermal barrier coatings and ceramic seal systems, demonstrated the practicality of an advanced turbine clearance control system and an advanced fan design in the JT9D engine, and demonstrated the advantages of modern cooling, sealing, and aerodynamic designs in the high pressure turbine and compressor of the JT8D engine. Several of these improvements are already in airline service in JT8D and JT9D engines, and others will enter service soon in advanced models of these engines. In addition, the technology advances are being transferred to completely new engine configurations, the PW2037 engine and the NASA sponsored Energy Efficient Engine.

  20. Structured system engineering methodologies used to develop a nuclear thermal propulsion engine

    NASA Technical Reports Server (NTRS)

    Corban, R.; Wagner, R.

    1993-01-01

    To facilitate the development of a space nuclear thermal propulsion engine for manned flights to Mars, requirements must be established early in the technology development cycle. The long lead times for the acquisition of the engine system and nuclear test facilities demands that the engine system size, performance and safety goals be defined at the earliest possible time. These systems are highly complex and require a large multidisciplinary systems engineering team to develop and track requirements, and to ensure that the as-built system reflects the intent of the mission. A methodology has been devised which uses sophisticated computer tools to effectively develop and interpret functional requirements, and furnish these to the specification level for implementation.

  1. On the estimation algorithm used in adaptive performance optimization of turbofan engines

    NASA Technical Reports Server (NTRS)

    Espana, Martin D.; Gilyard, Glenn B.

    1993-01-01

    The performance seeking control algorithm is designed to continuously optimize the performance of propulsion systems. The performance seeking control algorithm uses a nominal model of the propulsion system and estimates, in flight, the engine deviation parameters characterizing the engine deviations with respect to nominal conditions. In practice, because of measurement biases and/or model uncertainties, the estimated engine deviation parameters may not reflect the engine's actual off-nominal condition. This factor has a necessary impact on the overall performance seeking control scheme exacerbated by the open-loop character of the algorithm. The effects produced by unknown measurement biases over the estimation algorithm are evaluated. This evaluation allows for identification of the most critical measurements for application of the performance seeking control algorithm to an F100 engine. An equivalence relation between the biases and engine deviation parameters stems from an observability study; therefore, it is undecided whether the estimated engine deviation parameters represent the actual engine deviation or whether they simply reflect the measurement biases. A new algorithm, based on the engine's (steady-state) optimization model, is proposed and tested with flight data. When compared with previous Kalman filter schemes, based on local engine dynamic models, the new algorithm is easier to design and tune and it reduces the computational burden of the onboard computer.

  2. Piston engine intake and exhaust system design

    NASA Astrophysics Data System (ADS)

    Davies, P. O. A. L.

    1993-07-01

    The aim of intake and exhaust system design is to control the transfer of acoustic energy from the sources and its emission by the system with minimal loss of engine performance. A rational design process depends on the adoption of a design methodology based on predictive modeling of acoustic behavior. Virtually any system geometry can be modeled by breaking it down to a sequence of simple elements or chambers. An initial design layout is then produced with simple parametric models of individual element behavior. This design is then refined to prototype level by systematic modification of detail using realistic assessments of system performance in its operational environment. Following prototype validation by practical testing, further necessary development is again assisted by predictive modeling. The application of appropriate procedures is illustrated by a series of practical examples. These concern improvements in interior noise by control of intake noise, of vehicle performance by reducing flow losses, of the environment by control of exhaust emissions, and lastly with the control of flow noise. The report concludes with a brief outline of current and new developments involving integrated design procedures.

  3. Modern Medical Engineering and Health Information Systems

    ERIC Educational Resources Information Center

    Davis, John F.

    1975-01-01

    Describes the impact of medical engineering and system design on hospital design and construction, health care in the home and hospital, equipment design, information systems, and health resources utilization. (GS)

  4. Hydrogen-methane fuel control systems for turbojet engines

    NASA Technical Reports Server (NTRS)

    Goldsmith, J. S.; Bennett, G. W.

    1973-01-01

    Design, development, and test of a fuel conditioning and control system utilizing liquid methane (natural gas) and liquid hydrogen fuels for operation of a J85 jet engine were performed. The experimental program evaluated the stability and response of an engine fuel control employing liquid pumping of cryogenic fuels, gasification of the fuels at supercritical pressure, and gaseous metering and control. Acceptably stable and responsive control of the engine was demonstrated throughout the sea level power range for liquid gas fuel and up to 88 percent engine speed using liquid hydrogen fuel.

  5. Analysis of a topping-cycle, aircraft, gas-turbine-engine system which uses cryogenic fuel

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Fishbach, L. H.

    1984-01-01

    A topping-cycle aircraft engine system which uses a cryogenic fuel was investigated. This system consists of a main turboshaft engine that is mechanically coupled (by cross-shafting) to a topping loop, which augments the shaft power output of the system. The thermodynamic performance of the topping-cycle engine was analyzed and compared with that of a reference (conventional) turboshaft engine. For the cycle operating conditions selected, the performance of the topping-cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping-cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping-cycle engine is comparable with that of the reference turboshaft engine.

  6. State analysis requirements database for engineering complex embedded systems

    NASA Technical Reports Server (NTRS)

    Bennett, Matthew B.; Rasmussen, Robert D.; Ingham, Michel D.

    2004-01-01

    It has become clear that spacecraft system complexity is reaching a threshold where customary methods of control are no longer affordable or sufficiently reliable. At the heart of this problem are the conventional approaches to systems and software engineering based on subsystem-level functional decomposition, which fail to scale in the tangled web of interactions typically encountered in complex spacecraft designs. Furthermore, there is a fundamental gap between the requirements on software specified by systems engineers and the implementation of these requirements by software engineers. Software engineers must perform the translation of requirements into software code, hoping to accurately capture the systems engineer's understanding of the system behavior, which is not always explicitly specified. This gap opens up the possibility for misinterpretation of the systems engineer's intent, potentially leading to software errors. This problem is addressed by a systems engineering tool called the State Analysis Database, which provides a tool for capturing system and software requirements in the form of explicit models. This paper describes how requirements for complex aerospace systems can be developed using the State Analysis Database.

  7. Engine Icing Modeling and Simulation (Part 2): Performance Simulation of Engine Rollback Phenomena

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Guo, Ten-Huei; Veres, Joseph P.; Jorgenson, Philip C. E.

    2011-01-01

    Ice buildup in the compressor section of a commercial aircraft gas turbine engine can cause a number of engine failures. One of these failure modes is known as engine rollback: an uncommanded decrease in thrust accompanied by a decrease in fan speed and an increase in turbine temperature. This paper describes the development of a model which simulates the system level impact of engine icing using the Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k). When an ice blockage is added to C-MAPSS40k, the control system responds in a manner similar to that of an actual engine, and, in cases with severe blockage, an engine rollback is observed. Using this capability to simulate engine rollback, a proof-of-concept detection scheme is developed and tested using only typical engine sensors. This paper concludes that the engine control system s limit protection is the proximate cause of iced engine rollback and that the controller can detect the buildup of ice particles in the compressor section. This work serves as a feasibility study for continued research into the detection and mitigation of engine rollback using the propulsion control system.

  8. Performance Engineering Research Center and RECOVERY. Performance Engineering Research Institution SciDAC-e Augmentation. Performance enhancement

    SciTech Connect

    Hollingsworth, Jeffrey K.

    2015-10-12

    This project concentrated on various ways to improve the measurement and tuning large-scale parallel applications. This project was supplement to the project DE-FC0206ER25763 (“Performance Engineering Research Center”). The research conducted during this project is summarized in this report. The complete details of the work are available in the ten publications listed at the end of the report. It also supported the Ph.D. studies of three students and one research scientist.

  9. Engine Data Interpretation System (EDIS), phase 2

    NASA Technical Reports Server (NTRS)

    Cost, Thomas L.; Hofmann, Martin O.

    1991-01-01

    A prototype of an expert system was developed which applies qualitative constraint-based reasoning to the task of post-test analysis of data resulting from a rocket engine firing. Data anomalies are detected and corresponding faults are diagnosed. Engine behavior is reconstructed using measured data and knowledge about engine behavior. Knowledge about common faults guides but does not restrict the search for the best explanation in terms of hypothesized faults. The system contains domain knowledge about the behavior of common rocket engine components and was configured for use with the Space Shuttle Main Engine (SSME). A graphical user interface allows an expert user to intimately interact with the system during diagnosis. The system was applied to data taken during actual SSME tests where data anomalies were observed.

  10. Visualizing systems engineering data with Java

    SciTech Connect

    Barter, Robert H.; Vinzant, Aleta

    1998-11-10

    Systems Engineers are required to deal with complex sets of data. To be useful, the data must be managed effectively, and presented in meaningful terms to a wide variety of information consumers. Two software patterns are presented as the basis for exploring the visualization of systems engineering data. The Model, View, Controller pattern defines an information management system architecture. The Entity, Relation, Attribute pattern defines the information model. MVC "Views" then form the basis for the user interface between the information consumer and the MVC "Controller"/"Model" combination. A Java tool set is described for exploring alternative views into the underlying complex data structures encountered in systems engineering.

  11. Study on Fault Diagnostics of a Turboprop Engine Using Inverse Performance Model and Artificial Intelligent Methods

    NASA Astrophysics Data System (ADS)

    Kong, Changduk; Lim, Semyeong

    2011-12-01

    Recently, the health monitoring system of major gas path components of gas turbine uses mostly the model based method like the Gas Path Analysis (GPA). This method is to find quantity changes of component performance characteristic parameters such as isentropic efficiency and mass flow parameter by comparing between measured engine performance parameters such as temperatures, pressures, rotational speeds, fuel consumption, etc. and clean engine performance parameters without any engine faults which are calculated by the base engine performance model. Currently, the expert engine diagnostic systems using the artificial intelligent methods such as Neural Networks (NNs), Fuzzy Logic and Genetic Algorithms (GAs) have been studied to improve the model based method. Among them the NNs are mostly used to the engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base if there are large amount of learning data. In addition, it has a very complex structure for finding effectively single type faults or multiple type faults of gas path components. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measured performance data, and proposes a fault diagnostic system using the base engine performance model and the artificial intelligent methods such as Fuzzy logic and Neural Network. The proposed diagnostic system isolates firstly the faulted components using Fuzzy Logic, then quantifies faults of the identified components using the NN leaned by fault learning data base, which are obtained from the developed base performance model. In leaning the NN, the Feed Forward Back Propagation (FFBP) method is used. Finally, it is verified through several test examples that the component faults implanted arbitrarily in the engine are well isolated and quantified by the proposed diagnostic system.

  12. A Historical Systems Study of Liquid Rocket Engine Throttling Capabilities

    NASA Technical Reports Server (NTRS)

    Betts, Erin M.; Frederick, Robert A., Jr.

    2010-01-01

    This is a comprehensive systems study to examine and evaluate throttling capabilities of liquid rocket engines. The focus of this study is on engine components, and how the interactions of these components are considered for throttling applications. First, an assessment of space mission requirements is performed to determine what applications require engine throttling. A background on liquid rocket engine throttling is provided, along with the basic equations that are used to predict performance. Three engines are discussed that have successfully demonstrated throttling. Next, the engine system is broken down into components to discuss special considerations that need to be made for engine throttling. This study focuses on liquid rocket engines that have demonstrated operational capability on American space launch vehicles, starting with the Apollo vehicle engines and ending with current technology demonstrations. Both deep throttling and shallow throttling engines are discussed. Boost and sustainer engines have demonstrated throttling from 17% to 100% thrust, while upper stage and lunar lander engines have demonstrated throttling in excess of 10% to 100% thrust. The key difficulty in throttling liquid rocket engines is maintaining an adequate pressure drop across the injector, which is necessary to provide propellant atomization and mixing. For the combustion chamber, cooling can be an issue at low thrust levels. For turbomachinery, the primary considerations are to avoid cavitation, stall, surge, and to consider bearing leakage flows, rotordynamics, and structural dynamics. For valves, it is necessary to design valves and actuators that can achieve accurate flow control at all thrust levels. It is also important to assess the amount of nozzle flow separation that can be tolerated at low thrust levels for ground testing.

  13. Closing the gap in systems engineering education for the space industry

    NASA Technical Reports Server (NTRS)

    Carlisle, R.

    1986-01-01

    The education of system engineers with emphasis on designing systems for space applications is discussed. System engineers determine the functional requirements, performance needs, and implementation procedures for proposed systems and their education is based on aeronautics and mathematics. Recommendations from industry for improving the curriculum of system engineers at the undergraduate and graduate levels are provided. The assistance provided by companies to the education of system engineers is examined.

  14. Quiet Clean Short-haul Experimental Engine (QCSEE). Under-The-Wing (UTW) engine boilerplate nacelle test report. Volume 3: Mechanical performance

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Results of initial tests of the under the wing experimental engine and boilerplate nacelle are presented. The mechanical performance of the engine is reported with emphasis on the advanced technology components. Technology elements of the propulsion system covered include: system dynamics, composite fan blades, reduction gear, lube and accessory drive system, fan frame, inlet, core cowl cooling, fan exhaust nozzle, and digital control system.

  15. Performance Evaluation of Hybrid Gas Turbine Engine Embedded with Pulse Detonation Combustor

    NASA Astrophysics Data System (ADS)

    Deng, Jun-Xiang; Yan, Chuan-Jun; Zheng, Long-Xi; Huang, Xi-Qiao

    2011-09-01

    The numerical investigations of performance evaluation of a hybrid gas turbine engine embedded with a pulse detonation combustor (PDC) were performed to examine the improvement of the performance of the hybrid propulsion system. The calculation model and method were described. The architecture, configuration and size of detonation tubes were investigated in the calculation. Two models of detonation tube exit temperature were utilized. Eight configuration choices for the PDC based on the calculation model were designed. Specific fuel consumption of a hybrid gas turbine engine was compared with that of the baseline engine at the condition of the same engine net thrust. The experimental research of a PDC interacted with a radial flow turbine of a turbocharger was conducted. The numerical results show that if the net thrust of hybrid PDC engine is matched to that of baseline engine, specific fuel consumption of hybrid PDC engine is 20-25% less than that of baseline engine. The total volume of the hybrid engine combustor is reduced. The incorporation of PDC into gas turbine engine can improve the performance of hybrid PDC engine, decrease the combustor weight, and increase the thrust-weight ratio. The experimental results show that the fully developed detonation waves are achieved in the experimental apparatus.

  16. Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.

    1986-01-01

    In support of the U.S. Department of Energy's Stirling Engine Highway Vehicle Systems program, the NASA Lewis Research Center investigated whether bypassing the P-40 Stirling engine heater during regenerative cooling would improve engine performance. The Lewis nodal-analysis Stirling engine computer simulation was used for this investigation. Results for the heater-bypass concept showed no significant improvement in the indicated thermal efficiency for the P-40 Stirling engine operating at full-power and part-power conditions. Optimizing the heater tube length produced a small increase in the indicated thermal efficiency with the heater-bypass concept.

  17. Performance evaluation of ground based radar systems

    NASA Astrophysics Data System (ADS)

    Grant, Stanley E.

    1994-06-01

    Ground based radar systems are a critical resource to the command, control, and communications system. This thesis provides the tools and methods to better understand the actual performance of an operational ground based radar system. This thesis defines two measurable performance standards: (1) the baseline performance, which is based on the sensor's internal characteristics, and (2) the theoretical performance, which considers not only the sensor's internal characteristics, but also the effects of the surrounding terrain and atmosphere on the sensor's performance. The baseline radar system performance, often used by operators, contractors, and radar modeling software to determine the expected system performance, is a simplistic and unrealistic means to predict actual radar system performance. The theoretical radar system performance is more complex; but, the results are much more indicative of the actual performance of an operational radar system. The AN/UPS-1 at the Naval Postgraduate School was used as the system under test to illustrate the baseline and theoretical radar system performance. The terrain effects are shown by performing a multipath study and producing coverage diagrams. The key variables used to construct the multipath study and coverage diagrams are discussed in detail. The atmospheric effects are illustrated by using the Integrated Refractive Effects Prediction System (IREPS) and the Engineer's Refractive Effects Prediction System (EREPS) software tools to produce propagations conditions summaries and coverage displays.

  18. CF6 Jet Engine Performance Improvement: High Pressure Turbine Active Clearance Control

    NASA Technical Reports Server (NTRS)

    Rich, S. E.; Fasching, W. A.

    1982-01-01

    An active clearance control system was developed which reduces fuel consumption and performance degradation. This system utilizes compressor discharge air during takeoff and fan discharge air during cruise to impinge on the shroud structure to improve the thermal response. The system was evaluated in component and engine tests. The test results demonstrated a performance improvement of 0.7 percent in cruise SFC.

  19. Engineering of the Magnetized Target Fusion Propulsion System

    NASA Technical Reports Server (NTRS)

    Statham, G.; White, S.; Adams, R. B.; Thio, Y. C. F.; Santarius, J.; Alexander, R.; Chapman, J.; Fincher, S.; Philips, A.; Polsgrove, T.

    2003-01-01

    Engineering details are presented for a magnetized target fusion (MTF) propulsion system designed to support crewed missions to the outer solar system. Basic operation of an MTF propulsion system is introduced. Structural, thermal, radiation-management and electrical design details are presented. The propellant storage and supply system design is also presented. A propulsion system mass estimate and associated performance figures are given. The advantages of helium-3 as a fusion fuel for an advanced MTF system are discussed.

  20. Numerical Modeling of Pulse Detonation Rocket Engine Gasdynamics and Performance

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This paper presents viewgraphs on the numerical modeling of pulse detonation rocket engines (PDRE), with an emphasis on the Gasdynamics and performance analysis of these engines. The topics include: 1) Performance Analysis of PDREs; 2) Simplified PDRE Cycle; 3) Comparison of PDRE and Steady-State Rocket Engines (SSRE) Performance; 4) Numerical Modeling of Quasi 1-D Rocket Flows; 5) Specific PDRE Geometries Studied; 6) Time-Accurate Thrust Calculations; 7) PDRE Performance (Geometries A B C and D); 8) PDRE Blowdown Gasdynamics (Geom. A B C and D); 9) PDRE Geometry Performance Comparison; 10) PDRE Blowdown Time (Geom. A B C and D); 11) Specific SSRE Geometry Studied; 12) Effect of F-R Chemistry on SSRE Performance; 13) PDRE/SSRE Performance Comparison; 14) PDRE Performance Study; 15) Grid Resolution Study; and 16) Effect of F-R Chemistry on SSRE Exit Species Mole Fractions.

  1. Systems Engineering and Integration for Technology Programs

    NASA Technical Reports Server (NTRS)

    Kennedy, Kruss J.

    2006-01-01

    The Architecture, Habitability & Integration group (AH&I) is a system engineering and integration test team within the NASA Crew and Thermal Systems Division (CTSD) at Johnson Space Center. AH&I identifies and resolves system-level integration issues within the research and technology development community. The timely resolution of these integration issues is fundamental to the development of human system requirements and exploration capability. The integration of the many individual components necessary to construct an artificial environment is difficult. The necessary interactions between individual components and systems must be approached in a piece-wise fashion to achieve repeatable results. A formal systems engineering (SE) approach to define, develop, and integrate quality systems within the life support community has been developed. This approach will allow a Research & Technology Program to systematically approach the development, management, and quality of technology deliverables to the various exploration missions. A tiered system engineering structure has been proposed to implement best systems engineering practices across all development levels from basic research to working assemblies. These practices will be implemented through a management plan across all applicable programs, projects, elements and teams. While many of the engineering practices are common to other industries, the implementation is specific to technology development. An accounting of the systems engineering management philosophy will be discussed and the associated programmatic processes will be presented.

  2. ENGINEL: A single rotor turbojet engine cycle match performance program

    NASA Technical Reports Server (NTRS)

    Lovell, W. A.

    1977-01-01

    ENGINEL is a computer program which was developed to generate the design and off-design performance of a single rotor turbojet engine with or without afterburning using a cycle match procedure. It is capable of producing engine performance over a wide range of altitudes and Mach numbers. The flexibility, of operating with a variable geometry turbine, for improved off-design fuel consumption or with a fixed geometry turbine as in conventional turbojets, has been incorporated. In addition, the option of generation engine performance with JP4, liquid hydrogen or methane as fuel is provided.

  3. Analysis of thermoelastohydrodynamic performance of journal misaligned engine main bearings

    NASA Astrophysics Data System (ADS)

    Bi, Fengrong; Shao, Kang; Liu, Changwen; Wang, Xia; Zhang, Jian

    2015-05-01

    To understand the engine main bearings' working condition is important in order to improve the performance of engine. However, thermal effects and thermal effect deformations of engine main bearings are rarely considered simultaneously in most studies. A typical finite element model is selected and the effect of thermoelastohydrodynamic(TEHD) reaction on engine main bearings is investigated. The calculated method of main bearing's thermal hydrodynamic reaction and journal misalignment effect is finite difference method, and its deformation reaction is calculated by using finite element method. The oil film pressure is solved numerically with Reynolds boundary conditions when various bearing characteristics are calculated. The whole model considers a temperature-pressure-viscosity relationship for the lubricant, surface roughness effect, and also an angular misalignment between the journal and the bearing. Numerical simulations of operation of a typical I6 diesel engine main bearing is conducted and importance of several contributing factors in mixed lubrication is discussed. The performance characteristics of journal misaligned main bearings under elastohydrodynamic(EHD) and TEHD loads of an I6 diesel engine are received, and then the journal center orbit movement, minimum oil film thickness and maximum oil film pressure of main bearings are estimated over a wide range of engine operation. The model is verified through the comparison with other present models. The TEHD performance of engine main bearings with various effects under the influences of journal misalignment is revealed, this is helpful to understand EHD and TEHD effect of misaligned engine main bearings.

  4. Congeneration system with a Stirling engine

    SciTech Connect

    Meijer, R.J.; Meijer, E.J.; Godett, T.M.

    1991-12-24

    This patent describes a cogeneration system for producing process heat for useful purposes and electric energy. It comprises an electric generator; a Stirling cycle engine having an output shaft operatively coupled to the generator for driving the generator, the engine including at least one internal fuel combustor; means for circulating a cooling liquid about the generator and engine to extract heat therefrom; an exhaust system coupled with the engine for exhausting combustion gases from the engine, the exhaust system including a condensing heat exchanger for cooling the combustion gases below the condensing, temperature of the water vapor in the exhaust gases; means for directing the cooling liquid around the condensing heat exchanger to extract heat therefrom and heat the liquid; and means for directing the cooling liquid for useful purposes.

  5. Systems engineering: A formal approach. Part 1: System concepts

    NASA Astrophysics Data System (ADS)

    Vanhee, K. M.

    1993-03-01

    Engineering is the scientific discipline focused on the creation of new artifacts that are supposed to be of some use to our society. Different types of artifacts require different engineering approaches. However, in all these disciplines the development of a new artifact is divided into stages. Three stages can always be recognized: Analysis, Design, and Realization. The book considers only the first two stages of the development process. It focuses on a specific type of artifacts, called discrete dynamic systems. These systems consist of active components of actors that consume and produce passive components or tokens. Three subtypes are studied in more detail: business systems (like a factory or restaurant), information systems (whether automated or not), and automated systems (systems that are controlled by an automated information system). The first subtype is studied by industrial engineers, the last by software engineers and electrical engineers, whereas the second is a battlefield for all three disciplines. The union of these disciplines is called systems engineering.

  6. A Waste Heat Recovery System for Light Duty Diesel Engines

    SciTech Connect

    Briggs, Thomas E; Wagner, Robert M; Edwards, Kevin Dean; Curran, Scott; Nafziger, Eric J

    2010-01-01

    In order to achieve proposed fuel economy requirements, engines must make better use of the available fuel energy. Regardless of how efficient the engine is, there will still be a significant fraction of the fuel energy that is rejected in the exhaust and coolant streams. One viable technology for recovering this waste heat is an Organic Rankine Cycle. This cycle heats a working fluid using these heat streams and expands the fluid through a turbine to produce shaft power. The present work was the development of such a system applied to a light duty diesel engine. This lab demonstration was designed to maximize the peak brake thermal efficiency of the engine, and the combined system achieved an efficiency of 44.4%. The design of the system is discussed, as are the experimental performance results. The system potential at typical operating conditions was evaluated to determine the practicality of installing such a system in a vehicle.

  7. JT9D-7A (SP) jet engine performance deterioration trends

    NASA Technical Reports Server (NTRS)

    Richter, G. P.; Olsson, W. J.; Andersen, N. B.

    1980-01-01

    The levels, trends, and causes of engine performance deterioration were investigated. A series of installed engine calibrations (both on-the-ground and in-flight) were performed on two new Pan American World Airways 747 SP aircraft. The performance data gathered covered from before the first flight through approximately 1000 flight cycles and 6900 flight hours. To accomplish the calibrations a special instrumentation system for ground testing of installed engines over a broad power range was used along with performing concurrent in-flight engine calibrations under revenue service conditions. Results of the analysis of the data, which provide a better understanding of short and long term performance deterioration of both engines and modules are presented.

  8. Dual Engine application of the Performance Seeking Control algorithm

    NASA Technical Reports Server (NTRS)

    Mueller, F. D.; Nobbs, S. G.; Stewart, J. F.

    1993-01-01

    The Dual Engine Performance Seeking Control (PSC) flight/propulsion optimization program has been developed and will be flown during the second quarter of 1993. Previously, only single engine optimization was possible due to the limited capability of the on-board computer. The implementation of Dual Engine PSC has been made possible with the addition of a new state-of-the-art, higher throughput computer. As a result, the single engine PSC performance improvements already flown will be demonstrated on both engines, simultaneously. Dual Engine PSC will make it possible to directly compare aircraft performance with and without the improvements generated by PSC. With the additional thrust achieved with PSC, significant improvements in acceleration times and time to climb will be possible. PSC is also able to reduce deceleration time from supersonic speeds. This paper traces the history of the PSC program, describes the basic components of PSC, discusses the development and implementation of Dual Engine PSC including additions to the code, and presents predictions of the impact of Dual Engine PSC on aircraft performance.

  9. Methods for Measuring Search Engine Performance over Time.

    ERIC Educational Resources Information Center

    Bar-Ilan, Judit

    2002-01-01

    Introduces methods for evaluating Web search engine performance over a time period. Describes the necessary setup for such studies, illustrates the use of these measures through a specific example, and recommends the use of the measures as a guideline for testing and improving search engine functionality. (Author/LRW)

  10. Process Systems Engineering Education: Learning by Research

    ERIC Educational Resources Information Center

    Abbas, A.; Alhammadi, H. Y.; Romagnoli, J. A.

    2009-01-01

    In this paper, we discuss our approach in teaching the final-year course Process Systems Engineering. Students are given ownership of the course by transferring to them the responsibility of learning. A project-based group environment stimulates learning while solving a real engineering problem. We discuss postgraduate student involvement and how…

  11. System safety in Stirling engine development

    NASA Technical Reports Server (NTRS)

    Bankaitis, H.

    1981-01-01

    The DOE/NASA Stirling Engine Project Office has required that contractors make safety considerations an integral part of all phases of the Stirling engine development program. As an integral part of each engine design subtask, analyses are evolved to determine possible modes of failure. The accepted system safety analysis techniques (Fault Tree, FMEA, Hazards Analysis, etc.) are applied in various degrees of extent at the system, subsystem and component levels. The primary objectives are to identify critical failure areas, to enable removal of susceptibility to such failures or their effects from the system and to minimize risk.

  12. Aircraft engine mathematical model - linear system approach

    NASA Astrophysics Data System (ADS)

    Rotaru, Constantin; Roateşi, Simona; Cîrciu, Ionicǎ

    2016-06-01

    This paper examines a simplified mathematical model of the aircraft engine, based on the theory of linear and nonlinear systems. The dynamics of the engine was represented by a linear, time variant model, near a nominal operating point within a finite time interval. The linearized equations were expressed in a matrix form, suitable for the incorporation in the MAPLE program solver. The behavior of the engine was included in terms of variation of the rotational speed following a deflection of the throttle. The engine inlet parameters can cover a wide range of altitude and Mach numbers.

  13. System engineering toolbox for design-oriented engineers

    NASA Technical Reports Server (NTRS)

    Goldberg, B. E.; Everhart, K.; Stevens, R.; Babbitt, N., III; Clemens, P.; Stout, L.

    1994-01-01

    This system engineering toolbox is designed to provide tools and methodologies to the design-oriented systems engineer. A tool is defined as a set of procedures to accomplish a specific function. A methodology is defined as a collection of tools, rules, and postulates to accomplish a purpose. For each concept addressed in the toolbox, the following information is provided: (1) description, (2) application, (3) procedures, (4) examples, if practical, (5) advantages, (6) limitations, and (7) bibliography and/or references. The scope of the document includes concept development tools, system safety and reliability tools, design-related analytical tools, graphical data interpretation tools, a brief description of common statistical tools and methodologies, so-called total quality management tools, and trend analysis tools. Both relationship to project phase and primary functional usage of the tools are also delineated. The toolbox also includes a case study for illustrative purposes. Fifty-five tools are delineated in the text.

  14. A systems engineering primer for every engineer and scientist

    SciTech Connect

    Edwards, William R.

    2001-12-10

    The Systems Engineering (SE) staff at LBNL has generated the following artifacts to assist projects with implementing a systems approach: (1) The present document that focuses on the what, why, and when of SE. It also provides a simple case-study to illustrate several SE tasks. (2) A web site with primary emphasis on the project life-cycle and workflow, (http://www-eng.LBNL.gov/Systems/index.html). It includes: SE guidelines and principles; A list of in-house tools; Templates; Case studies with ''how to'' examples; and Links to useful SE material. These sources are living documents to be updated as necessary. The viewpoint adopted in this document is that what LBNL engineers and scientists need is a set of principles and guiding practices for developing R and D systems rather than a ''cookbook''. There are many excellent ''how to'' resources such as the ''INCOSE Systems Engineering Handbook'' to guide those in search of more details. The SE staff is another resource available to consult and support projects. This document specifies SE principles and activities that are applicable to all LBNL projects independent of their specific differences. Each project should tailor the SE implementation to meet its individual needs and culture including project-specific resources, procedures, products, and tools.

  15. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    SciTech Connect

    R. Jarek

    2005-08-29

    The purpose of this model report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The resulting seepage evaporation and gas abstraction models are used in the total system performance assessment for the license application (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2005 [DIRS 173782], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports. To be consistent with other project documents that address features, events, and processes (FEPs), Table 6.14.1 of the current report includes updates to FEP numbers and FEP subjects for two FEPs identified in the technical work plan (TWP) governing this report (BSC 2005 [DIRS 173782]). FEP 2.1.09.06.0A (Reduction-oxidation potential in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.06.0B (Reduction-oxidation potential in Drifts; see Table 6.14-1). FEP 2.1.09.07.0A (Reaction kinetics in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.07.0B (Reaction kinetics in Drifts; see Table 6.14-1). These deviations from the TWP are justified because they improve integration with FEPs documents. The updates

  16. Numerical Modeling of Pulse Detonation Rocket Engine Gasdynamics And Performance

    NASA Technical Reports Server (NTRS)

    Morris, Christopher I.

    2004-01-01

    Pulse detonation rocket engines (PDREs) offer potential performance improvements over conventional designs, but represent a challenging modeling task. A quasi-1-D, finite-rate chemistry computational fluid dynamics model for PDREs is described and implemented. Four different PDRE geometries are evaluated in this work: a baseline detonation tube, a detonation tube with a straight extension, and a detonation tube with two types of converging-diverging (C-D) nozzles. The effect of extension length and C-D nozzle area ratio on the single-shot gasdynamics and performance of a PDRE is studied over a wide range of blowdown pressure ratios (1-1000). The results indicate that a C-D nozzle is generally more effective than a straight extension in improving PDRE performance, particularly at higher pressure ratios. Additionally, the results show that the blowdown process of the C-D nozzle systems could be beneficially cut off well before the pressure at the end-wall reaches the ambient value. The performance results are also compared to a steady-state rocket system using similar modeling assumptions.

  17. Fluid design studies of integrated modular engine system

    NASA Technical Reports Server (NTRS)

    Frankenfield, Bruce; Carek, Jerry

    1993-01-01

    A study was performed to develop a fluid system design and show the feasibility of constructing an integrated modular engine (IME) configuration, using an expander cycle engine. The primary design goal of the IME configuration was to improve the propulsion system reliability. The IME fluid system was designed as a single fault tolerant system, while minimizing the required fluid components. This study addresses the design of the high pressure manifolds, turbopumps and thrust chambers for the IME configuration. A physical layout drawing was made, which located each of the fluid system components, manifolds and thrust chambers. Finally, a comparison was made between the fluid system designs of an IME system and a non-network (clustered) engine system.

  18. Comparing Web search engine performance in searching consumer health information: evaluation and recommendations.

    PubMed Central

    Wu, G; Li, J

    1999-01-01

    Identifying and accessing reliable, relevant consumer health information rapidly on the Internet may challenge the health sciences librarian and layperson alike. In this study, seven search engines are compared using representative consumer health topics for their content relevancy, system features, and attributes. The paper discusses evaluation criteria; systematically compares relevant results; analyzes performance in terms of the strengths and weaknesses of the search engines; and illustrates effective search engine selection, search formulation, and strategies. PMID:10550031

  19. An Investigation Into the Performance of a Miniature Diesel Engine

    ERIC Educational Resources Information Center

    Stevenson, P. W.

    1970-01-01

    Reports the procedures and results of a student investigation of the performance of a miniature diesel engine. The experiments include (1) torque measurement, (2) power measurement, and (3) variation of power output with applied load. Bibliography. (LC)

  20. Lean mixture engine testing and evaluation program. [for automobile engine pollution and fuel performances

    NASA Technical Reports Server (NTRS)

    Dowdy, M. W.; Hoehn, F. W.; Griffin, D. C.

    1975-01-01

    Experimental results for fuel consumption and emissions are presented for a 350 CID (5.7 liter) Chevrolet V-8 engine modified for lean operation with gasoline. The lean burn engine achieved peak thermal efficiency at an equivalence ratio of 0.75 and a spark advance of 60 deg BTDC. At this condition the lean burn engine demonstrated a 10% reduction in brake specific fuel consumption compared with the stock engine; however, NOx and hydrocarbon emissions were higher. With the use of spark retard and/or slightly lower equivalence ratios, the NOx emissions performance of the stock engine was matched while showing a 6% reduction in brake specific fuel consumption. Hydrocarbon emissions exceeded the stock values in all cases. Diagnostic data indicate that lean performance in the engine configuration tested is limited by ignition delay, cycle-to-cycle pressure variations, and cylinder-to-cylinder distribution.

  1. Engineering high-performance vertical cavity lasers

    SciTech Connect

    Lear, K.L.; Hou, H.Q.; Hietala, V.M.; Choquette, K.D.; Schneider, R.P. Jr.

    1996-12-31

    The cw and high-speed performance of vertical cavity surface emitting laser diodes (VCSELs) are affected by both electrical and optical issues arising from the geometry and fabrication of these devices. Structures with low resistance semiconductor mirrors and Al-oxide confinement layers address these issues and have produced record performance including 50% power conversion efficiency and modulation bandwidths up to 20 GHz at small bias currents.

  2. Integrated flight/propulsion control - Adaptive engine control system mode

    NASA Technical Reports Server (NTRS)

    Yonke, W. A.; Terrell, L. A.; Meyers, L. P.

    1985-01-01

    The adaptive engine control system mode (ADECS) which is developed and tested on an F-15 aircraft with PW1128 engines, using the NASA sponsored highly integrated digital electronic control program, is examined. The operation of the ADECS mode, as well as the basic control logic, the avionic architecture, and the airframe/engine interface are described. By increasing engine pressure ratio (EPR) additional thrust is obtained at intermediate power and above. To modulate the amount of EPR uptrim and to prevent engine stall, information from the flight control system is used. The performance benefits, anticipated from control integration are shown for a range of flight conditions and power settings. It is found that at higher altitudes, the ADECS mode can increase thrust as much as 12 percent, which is used for improved acceleration, improved turn rate, or sustained turn angle.

  3. CF6 jet engine performance improvement: New fan

    NASA Technical Reports Server (NTRS)

    Fasching, W. A.

    1980-01-01

    As part of the NASA sponsored engine component improvement program, and fan package was developed to reduce fuel consumption in current CF6 turbofan aircraft engine. The new fan package consist of an improved fan blade, reduced fan tip clearance due to a fan case stiffener, and a smooth fan casing tip shroud. CF6 engine performance and acoustic tests demonstrated the predicted 1.8% improvement in cruise sfc without an increase in engine noise. Power management thrust/fan speed characteristics were defined. Mechanical and structural integrity was demonstrated in model fan rotor photoelastic stress tests, full-size fan blade bench fatigue tests, and CF6 engine bird ingestion, crosswind, and cyclic endurance tests. The fan was certified in the CF6-500c2/E2 engines and is in commerical service on the Boeing 747-200, Douglas DC-10-30, and Atrbus industrie A300B aircraft.

  4. Mean Line Pump Flow Model in Rocket Engine System Simulation

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.; Lavelle, Thomas M.

    2000-01-01

    A mean line pump flow modeling method has been developed to provide a fast capability for modeling turbopumps of rocket engines. Based on this method, a mean line pump flow code PUMPA has been written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The pump code can model axial flow inducers, mixed-flow and centrifugal pumps. The code can model multistage pumps in series. The code features rapid input setup and computer run time, and is an effective analysis and conceptual design tool. The map generation capability of the code provides the map information needed for interfacing with a rocket engine system modeling code. The off-design and multistage modeling capabilities of the code permit parametric design space exploration of candidate pump configurations and provide pump performance data for engine system evaluation. The PUMPA code has been integrated with the Numerical Propulsion System Simulation (NPSS) code and an expander rocket engine system has been simulated. The mean line pump flow code runs as an integral part of the NPSS rocket engine system simulation and provides key pump performance information directly to the system model at all operating conditions.

  5. Performance of an irreversible quantum Carnot engine with spin 12.

    PubMed

    Wu, Feng; Chen, Lingen; Wu, Shuang; Sun, Fengrui; Wu, Chih

    2006-06-01

    The purpose of this paper is to investigate the effect of quantum properties of the working medium on the performance of an irreversible Carnot cycle with spin 12. The optimal relationship between the dimensionless power output P* versus the efficiency eta for the irreversible quantum Carnot engine with heat leakage and other irreversible losses is derived. Especially, the performances of the engine at low temperature limit and at high temperature limit are discussed. PMID:16774426

  6. AAHM 2012: Systems Engineer Leading the Way

    NASA Video Gallery

    Marco Midon, who is visually impaired, is highlighted for NASA's Black History Month. He is the Lead Systems Engineer who oversees the design and implementation of NASA ground stations in the area ...

  7. Performance Engineering/Organization Mapping: A Case Study.

    ERIC Educational Resources Information Center

    James, Randolph I.

    1987-01-01

    Describes how two methodologies for analyzing and improving performance--performance engineering and organization mapping--were used in a case study involving the purchasing department of an electric utility. Highlights include the establishment of a model of the desired results, measuring existing performance, and the designing of an improvement…

  8. Expedition 16 Flight Engineer Tani Performs EVA

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Astronaut Daniel Tani (top center), Expedition 16 flight engineer, participates in the second of five scheduled sessions of extravehicular activity (EVA) as construction continues on the International Space Station (ISS). During the 6-hour and 33-minute space walk, Tani and STS-120 mission specialist Scott Parazynski (out of frame), worked in tandem to disconnect cables from the P6 truss, allowing it to be removed from the Z1 truss. Tani also visually inspected the station's starboard Solar Alpha Rotary Joint (SARJ) and gathered samples of 'shavings' he found under the joint's multilayer insulation covers. The space walkers also outfitted the Harmony module, mated the power and data grapple fixture and reconfigured connectors on the starboard 1 (S1) truss that will allow the radiator on S1 to be deployed from the ground later. The moon is visible at lower center. The STS-120 mission launched from Kennedy Space Center's launch pad 39A at 11:38:19 a.m. (EDT) on October 23, 2007.

  9. Engines-only flight control system

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W. (Inventor); Gilyard, Glenn B (Inventor); Conley, Joseph L. (Inventor); Stewart, James F. (Inventor); Fullerton, Charles G. (Inventor)

    1994-01-01

    A backup flight control system for controlling the flightpath of a multi-engine airplane using the main drive engines is introduced. The backup flight control system comprises an input device for generating a control command indicative of a desired flightpath, a feedback sensor for generating a feedback signal indicative of at least one of pitch rate, pitch attitude, roll rate and roll attitude, and a control device for changing the output power of at least one of the main drive engines on each side of the airplane in response to the control command and the feedback signal.

  10. Implementing Systems Engineering on a CERCLA Project

    SciTech Connect

    Beitel, George Alois

    1999-06-01

    The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), enacted in 1980, provides a regulatory and legal mechanism to reduce risks from prior disposal of hazardous and toxic chemicals. Regulations, Standards, and Guidelines have been published to further define the CERCLA Process. The OU 7-10 Staged Interim Action Project at the Idaho National Engineering and Environmental Laboratory (INEEL) is a CERCLA project working to remediate the pre-1970 disposal pit in which transuranic materials have been disposed. This paper analyzes the CERCLA process from a systems engineering perspective and describes how systems engineering is implemented on this project.

  11. Parallelization of Rocket Engine System Software (Press)

    NASA Technical Reports Server (NTRS)

    Cezzar, Ruknet

    1996-01-01

    The main goal is to assess parallelization requirements for the Rocket Engine Numeric Simulator (RENS) project which, aside from gathering information on liquid-propelled rocket engines and setting forth requirements, involve a large FORTRAN based package at NASA Lewis Research Center and TDK software developed by SUBR/UWF. The ultimate aim is to develop, test, integrate, and suitably deploy a family of software packages on various aspects and facets of rocket engines using liquid-propellants. At present, all project efforts by the funding agency, NASA Lewis Research Center, and the HBCU participants are disseminated over the internet using world wide web home pages. Considering obviously expensive methods of actual field trails, the benefits of software simulators are potentially enormous. When realized, these benefits will be analogous to those provided by numerous CAD/CAM packages and flight-training simulators. According to the overall task assignments, Hampton University's role is to collect all available software, place them in a common format, assess and evaluate, define interfaces, and provide integration. Most importantly, the HU's mission is to see to it that the real-time performance is assured. This involves source code translations, porting, and distribution. The porting will be done in two phases: First, place all software on Cray XMP platform using FORTRAN. After testing and evaluation on the Cray X-MP, the code will be translated to C + + and ported to the parallel nCUBE platform. At present, we are evaluating another option of distributed processing over local area networks using Sun NFS, Ethernet, TCP/IP. Considering the heterogeneous nature of the present software (e.g., first started as an expert system using LISP machines) which now involve FORTRAN code, the effort is expected to be quite challenging.

  12. Stirling cycle engine and refrigeration systems

    NASA Technical Reports Server (NTRS)

    Higa, W. H. (Inventor)

    1976-01-01

    A Stirling cycle heat engine is disclosed in which displacer motion is controlled as a function of the working fluid pressure P sub 1 and a substantially constant pressure P sub 0. The heat engine includes an auxiliary chamber at the constant pressure P sub 0. An end surface of a displacer piston is disposed in the auxiliary chamber. During the compression portion of the engine cycle when P sub 1 rises above P sub 0 the displacer forces the working fluid to pass from the cold chamber to the hot chamber of the engine. During the expansion portion of the engine cycle the heated working fluid in the hot chamber does work by pushing down on the engine's drive piston. As the working fluid pressure P sub 1 drops below P sub 0 the displacer forces most of the working fluid in the hot chamber to pass through the regenerator to the cold chamber. The engine is easily combinable with a refrigeration section to provide a refrigeration system in which the engine's single drive piston serves both the engine and the refrigeration section.

  13. Performing Verification and Validation in Reuse-Based Software Engineering

    NASA Technical Reports Server (NTRS)

    Addy, Edward A.

    1999-01-01

    The implementation of reuse-based software engineering not only introduces new activities to the software development process, such as domain analysis and domain modeling, it also impacts other aspects of software engineering. Other areas of software engineering that are affected include Configuration Management, Testing, Quality Control, and Verification and Validation (V&V). Activities in each of these areas must be adapted to address the entire domain or product line rather than a specific application system. This paper discusses changes and enhancements to the V&V process, in order to adapt V&V to reuse-based software engineering.

  14. Generalized simulation technique for turbojet engine system analysis

    NASA Technical Reports Server (NTRS)

    Seldner, K.; Mihaloew, J. R.; Blaha, R. J.

    1972-01-01

    A nonlinear analog simulation of a turbojet engine was developed. The purpose of the study was to establish simulation techniques applicable to propulsion system dynamics and controls research. A schematic model was derived from a physical description of a J85-13 turbojet engine. Basic conservation equations were applied to each component along with their individual performance characteristics to derive a mathematical representation. The simulation was mechanized on an analog computer. The simulation was verified in both steady-state and dynamic modes by comparing analytical results with experimental data obtained from tests performed at the Lewis Research Center with a J85-13 engine. In addition, comparison was also made with performance data obtained from the engine manufacturer. The comparisons established the validity of the simulation technique.

  15. System Engineering for the NNSA Knowledge Base

    NASA Astrophysics Data System (ADS)

    Young, C.; Ballard, S.; Hipp, J.

    2006-05-01

    To improve ground-based nuclear explosion monitoring capability, GNEM R&E (Ground-based Nuclear Explosion Monitoring Research & Engineering) researchers at the national laboratories have collected an extensive set of raw data products. These raw data are used to develop higher level products (e.g. 2D and 3D travel time models) to better characterize the Earth at regional scales. The processed products and selected portions of the raw data are stored in an archiving and access system known as the NNSA (National Nuclear Security Administration) Knowledge Base (KB), which is engineered to meet the requirements of operational monitoring authorities. At its core, the KB is a data archive, and the effectiveness of the KB is ultimately determined by the quality of the data content, but access to that content is completely controlled by the information system in which that content is embedded. Developing this system has been the task of Sandia National Laboratories (SNL), and in this paper we discuss some of the significant challenges we have faced and the solutions we have engineered. One of the biggest system challenges with raw data has been integrating database content from the various sources to yield an overall KB product that is comprehensive, thorough and validated, yet minimizes the amount of disk storage required. Researchers at different facilities often use the same data to develop their products, and this redundancy must be removed in the delivered KB, ideally without requiring any additional effort on the part of the researchers. Further, related data content must be grouped together for KB user convenience. Initially SNL used whatever tools were already available for these tasks, and did the other tasks manually. The ever-growing volume of KB data to be merged, as well as a need for more control of merging utilities, led SNL to develop our own java software package, consisting of a low- level database utility library upon which we have built several

  16. A Systems-Level Perspective on Engine Ice Accretion

    NASA Technical Reports Server (NTRS)

    May, Ryan David; Guo, Ten-Huei; Simon, Donald L.

    2012-01-01

    Talk covers: (1) Problem of Engine Power Loss;(2) Modeling Engine Icing Effects; (3) Simulation of Engine Rollback; (4) Icing/Engine Control System Interaction; (5) Detection of Ice Accretion; (6) Potential Mitigation Strategies.

  17. Advancing the practice of systems engineering at JPL

    NASA Technical Reports Server (NTRS)

    Jansma, Patti A.; Jones, Ross M.

    2006-01-01

    In FY 2004, JPL launched an initiative to improve the way it practices systems engineering. The Lab's senior management formed the Systems Engineering Advancement (SEA) Project in order to "significantly advance the practice and organizational capabilities of systems engineering at JPL on flight projects and ground support tasks." The scope of the SEA Project includes the systems engineering work performed in all three dimensions of a program, project, or task: 1. the full life-cycle, i.e., concept through end of operations 2. the full depth, i.e., Program, Project, System, Subsystem, Element (SE Levels 1 to 5) 3. the full technical scope, e.g., the flight, ground and launch systems, avionics, power, propulsion, telecommunications, thermal, etc. The initial focus of their efforts defined the following basic systems engineering functions at JPL: systems architecture, requirements management, interface definition, technical resource management, system design and analysis, system verification and validation, risk management, technical peer reviews, design process management and systems engineering task management, They also developed a list of highly valued personal behaviors of systems engineers, and are working to inculcate those behaviors into members of their systems engineering community. The SEA Project is developing products, services, and training to support managers and practitioners throughout the entire system lifecycle. As these are developed, each one needs to be systematically deployed. Hence, the SEA Project developed a deployment process that includes four aspects: infrastructure and operations, communication and outreach, education and training, and consulting support. In addition, the SEA Project has taken a proactive approach to organizational change management and customer relationship management - both concepts and approaches not usually invoked in an engineering environment. This paper'3 describes JPL's approach to advancing the practice of

  18. Complex Adaptive Systems of Systems (CASOS) engineering environment.

    SciTech Connect

    Detry, Richard Joseph; Linebarger, John Michael; Finley, Patrick D.; Maffitt, S. Louise; Glass, Robert John, Jr.; Beyeler, Walter Eugene; Ames, Arlo Leroy

    2012-02-01

    Complex Adaptive Systems of Systems, or CASoS, are vastly complex physical-socio-technical systems which we must understand to design a secure future for the nation. The Phoenix initiative implements CASoS Engineering principles combining the bottom up Complex Systems and Complex Adaptive Systems view with the top down Systems Engineering and System-of-Systems view. CASoS Engineering theory and practice must be conducted together to develop a discipline that is grounded in reality, extends our understanding of how CASoS behave and allows us to better control the outcomes. The pull of applications (real world problems) is critical to this effort, as is the articulation of a CASoS Engineering Framework that grounds an engineering approach in the theory of complex adaptive systems of systems. Successful application of the CASoS Engineering Framework requires modeling, simulation and analysis (MS and A) capabilities and the cultivation of a CASoS Engineering Community of Practice through knowledge sharing and facilitation. The CASoS Engineering Environment, itself a complex adaptive system of systems, constitutes the two platforms that provide these capabilities.

  19. High energy density propulsion systems and small engine dynamometer

    NASA Astrophysics Data System (ADS)

    Hays, Thomas

    2009-07-01

    Scope and Method of Study. This study investigates all possible methods of powering small unmanned vehicles, provides reasoning for the propulsion system down select, and covers in detail the design and production of a dynamometer to confirm theoretical energy density calculations for small engines. Initial energy density calculations are based upon manufacturer data, pressure vessel theory, and ideal thermodynamic cycle efficiencies. Engine tests are conducted with a braking type dynamometer for constant load energy density tests, and show true energy densities in excess of 1400 WH/lb of fuel. Findings and Conclusions. Theory predicts lithium polymer, the present unmanned system energy storage device of choice, to have much lower energy densities than other conversion energy sources. Small engines designed for efficiency, instead of maximum power, would provide the most advantageous method for powering small unmanned vehicles because these engines have widely variable power output, loss of mass during flight, and generate rotational power directly. Theoretical predictions for the energy density of small engines has been verified through testing. Tested values up to 1400 WH/lb can be seen under proper operating conditions. The implementation of such a high energy density system will require a significant amount of follow-on design work to enable the engines to tolerate the higher temperatures of lean operation. Suggestions are proposed to enable a reliable, small-engine propulsion system in future work. Performance calculations show that a mature system is capable of month long flight times, and unrefueled circumnavigation of the globe.

  20. Morphology engineering of high performance binary oxide electrodes.

    PubMed

    Chen, Kunfeng; Sun, Congting; Xue, Dongfeng

    2015-01-14

    Advances in materials have preceded almost every major technological leap since the beginning of civilization. On the nanoscale and microscale, mastery over the morphology, size, and structure of a material enables control of its properties and enhancement of its usefulness for a given application, such as energy storage. In this review paper, our aim is to present a review of morphology engineering of high performance oxide electrode materials for electrochemical energy storage. We begin with the chemical bonding theory of single crystal growth to direct the growth of morphology-controllable materials. We then focus on the growth of various morphologies of binary oxides and their electrochemical performances for lithium ion batteries and supercapacitors. The morphology-performance relationships are elaborated by selecting examples in which there is already reasonable understanding for this relationship. Based on these comprehensive analyses, we proposed colloidal supercapacitor systems beyond morphology control on the basis of system- and ion-level design. We conclude this article with personal perspectives on the directions toward which future research in this field might take. PMID:25406718

  1. Engineering management of large scale systems

    NASA Technical Reports Server (NTRS)

    Sanders, Serita; Gill, Tepper L.; Paul, Arthur S.

    1989-01-01

    The organization of high technology and engineering problem solving, has given rise to an emerging concept. Reasoning principles for integrating traditional engineering problem solving with system theory, management sciences, behavioral decision theory, and planning and design approaches can be incorporated into a methodological approach to solving problems with a long range perspective. Long range planning has a great potential to improve productivity by using a systematic and organized approach. Thus, efficiency and cost effectiveness are the driving forces in promoting the organization of engineering problems. Aspects of systems engineering that provide an understanding of management of large scale systems are broadly covered here. Due to the focus and application of research, other significant factors (e.g., human behavior, decision making, etc.) are not emphasized but are considered.

  2. Complete modeling for systems of a marine diesel engine

    NASA Astrophysics Data System (ADS)

    Nahim, Hassan Moussa; Younes, Rafic; Nohra, Chadi; Ouladsine, Mustapha

    2015-03-01

    This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations. The whole engine system is divided into several functional blocks: cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocks are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocks and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocks. The simulator will be used, in future work, to study the engine performance in faulty conditions, and can be used to assist marine engineers in fault diagnosis and estimation (FDI) as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components. This program is a platform for fault simulator, to investigate the impact on sub-blocks engine's output of changing values for faults parameters such as: faulty fuel injector, leaky cylinder, worn fuel pump, broken piston rings, a dirty turbocharger, dirty air filter, dirty air cooler, air leakage, water leakage, oil leakage and contamination, fouling of heat exchanger, pumps wear, failure of injectors (and many others).

  3. System performance conclusions

    NASA Technical Reports Server (NTRS)

    Arndt, G. D.

    1980-01-01

    The advantages and disadvantages of reducing power levels and using antennas with diameters smaller than 1 Km were evaluated if rectenna costs and land usage requirements become major factors, operating at 5800 megahertz should be considered. Three sequences (random, incoherent phasing, and concentric rings - center to edge) provided satisfactory performance in that the resultant sidelobe levels during startup/ shutdown were lower than the steady-state levels present during normal operations. Grating lobe peaks and scattered power levels were used to determine the array/subarray mechanical alignment requirements. The antenna alignment requirement is 1 min or 3 min depending on phase control configuration. System error parameters were defined to minimize scattered microwave power.

  4. Big system: Interactive graphics for the engineer

    NASA Technical Reports Server (NTRS)

    Quenneville, C. E.

    1975-01-01

    The BCS Interactive Graphics System (BIG System) approach to graphics was presented, along with several significant engineering applications. The BIG System precompiler, the graphics support library, and the function requirements of graphics applications are discussed. It was concluded that graphics standardization and a device independent code can be developed to assure maximum graphic terminal transferability.

  5. Turbopump systems for liquid rocket engines

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The turbopump system, from preliminary design through rocket engine testing is examined. Selection of proper system type for each application and integration of the components into a working system are dealt with. Details are also given on the design of various components including inducers, pumps, turbines, gears, and bearings.

  6. A Framework for Performing Verification and Validation in Reuse Based Software Engineering

    NASA Technical Reports Server (NTRS)

    Addy, Edward A.

    1997-01-01

    Verification and Validation (V&V) is currently performed during application development for many systems, especially safety-critical and mission- critical systems. The V&V process is intended to discover errors, especially errors related to critical processing, as early as possible during the development process. The system application provides the context under which the software artifacts are validated. This paper describes a framework that extends V&V from an individual application system to a product line of systems that are developed within an architecture-based software engineering environment. This framework includes the activities of traditional application-level V&V, and extends these activities into domain engineering and into the transition between domain engineering and application engineering. The framework includes descriptions of the types of activities to be performed during each of the life-cycle phases, and provides motivation for the activities.

  7. Advanced Health Management System for the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Davidson, Matt; Stephens, John

    2004-01-01

    Boeing-Canoga Park (BCP) and NASA-Marshall Space Flight Center (NASA-MSFC) are developing an Advanced Health Management System (AHMS) for use on the Space Shuttle Main Engine (SSME) that will improve Shuttle safety by reducing the probability of catastrophic engine failures during the powered ascent phase of a Shuttle mission. This is a phased approach that consists of an upgrade to the current Space Shuttle Main Engine Controller (SSMEC) to add turbomachinery synchronous vibration protection and addition of a separate Health Management Computer (HMC) that will utilize advanced algorithms to detect and mitigate predefined engine anomalies. The purpose of the Shuttle AHMS is twofold; one is to increase the probability of successfully placing the Orbiter into the intended orbit, and the other is to increase the probability of being able to safely execute an abort of a Space Transportation System (STS) launch. Both objectives are achieved by increasing the useful work envelope of a Space Shuttle Main Engine after it has developed anomalous performance during launch and the ascent phase of the mission. This increase in work envelope will be the result of two new anomaly mitigation options, in addition to existing engine shutdown, that were previously unavailable. The added anomaly mitigation options include engine throttle-down and performance correction (adjustment of engine oxidizer to fuel ratio), as well as enhanced sensor disqualification capability. The HMC is intended to provide the computing power necessary to diagnose selected anomalous engine behaviors and for making recommendations to the engine controller for anomaly mitigation. Independent auditors have assessed the reduction in Shuttle ascent risk to be on the order of 40% with the combined system and a three times improvement in mission success.

  8. Performance of Diesel Engine Using Blended Crude Jatropha Oil

    NASA Astrophysics Data System (ADS)

    Kamarudin, Kamarul Azhar; Mohd Sazali, Nor Shahida Akma; Mohd Ali, Mas Fauzi; Alimin, Ahmad Jais; Khir, Saffiah Abdullah

    2010-06-01

    Vegetable oil presents a very promising alternative to diesel oil since it is renewable and has similar properties to the diesel. In view of this, crude jatropha oil is selected and its viscosity is reduced by blending it with diesel. Since jatropha oil has properties which are similar to mineral diesel, it can be used in compression ignition engines without any engine modification. This paper presents the results of investigation carried out on a four-cylinder, four strokes and indirect-injection diesel engine. The engine, operated using composition blends of crude jatropha oil and diesel, were compared with mineral diesel. An experimental investigation has been carried out to analyze the performance characteristics of a compression ignition engine from the blended fuel (5%, 10%, 20% and 30%). A naturally aspirated four-stroke indirect injection diesel engine was tested at full load conditions, speeds between 1000 and 3500 rpm with intervals of 500 rpm. Results obtained from the measures of torque, power, specific fuel consumptions, thermal efficiency and brake mean effective pressure are nearly the same between blended and diesel fuel. An overall graph shows that the performance of relevant parameters from blended fuel is most likely similar to the performance produced from diesel. The experimental results proved that the use of crude jatropha oil in compression ignition engines is a viable alternative to diesel.

  9. Developing the Next Generation of Science Data System Engineers

    NASA Technical Reports Server (NTRS)

    Moses, John F.; Behnke, Jeanne; Durachka, Christopher D.

    2016-01-01

    At Goddard, engineers and scientists with a range of experience in science data systems are needed to employ new technologies and develop advances in capabilities for supporting new Earth and Space science research. Engineers with extensive experience in science data, software engineering and computer-information architectures are needed to lead and perform these activities. The increasing types and complexity of instrument data and emerging computer technologies coupled with the current shortage of computer engineers with backgrounds in science has led the need to develop a career path for science data systems engineers and architects.The current career path, in which undergraduate students studying various disciplines such as Computer Engineering or Physical Scientist, generally begins with serving on a development team in any of the disciplines where they can work in depth on existing Goddard data systems or serve with a specific NASA science team. There they begin to understand the data, infuse technologies, and begin to know the architectures of science data systems. From here the typical career involves peermentoring, on-the-job training or graduate level studies in analytics, computational science and applied science and mathematics. At the most senior level, engineers become subject matter experts and system architect experts, leading discipline-specific data centers and large software development projects. They are recognized as a subject matter expert in a science domain, they have project management expertise, lead standards efforts and lead international projects. A long career development remains necessary not only because of the breadth of knowledge required across physical sciences and engineering disciplines, but also because of the diversity of instrument data being developed today both by NASA and international partner agencies and because multidiscipline science and practitioner communities expect to have access to all types of observational data

  10. Developing the Next Generation of Science Data System Engineers

    NASA Astrophysics Data System (ADS)

    Moses, J. F.; Durachka, C. D.; Behnke, J.

    2015-12-01

    At Goddard, engineers and scientists with a range of experience in science data systems are needed to employ new technologies and develop advances in capabilities for supporting new Earth and Space science research. Engineers with extensive experience in science data, software engineering and computer-information architectures are needed to lead and perform these activities. The increasing types and complexity of instrument data and emerging computer technologies coupled with the current shortage of computer engineers with backgrounds in science has led the need to develop a career path for science data systems engineers and architects. The current career path, in which undergraduate students studying various disciplines such as Computer Engineering or Physical Scientist, generally begins with serving on a development team in any of the disciplines where they can work in depth on existing Goddard data systems or serve with a specific NASA science team. There they begin to understand the data, infuse technologies, and begin to know the architectures of science data systems. From here the typical career involves peer mentoring, on-the-job training or graduate level studies in analytics, computational science and applied science and mathematics. At the most senior level, engineers become subject matter experts and system architect experts, leading discipline-specific data centers and large software development projects. They are recognized as a subject matter expert in a science domain, they have project management expertise, lead standards efforts and lead international projects. A long career development remains necessary not only because of the breath of knowledge required across physical sciences and engineering disciplines, but also because of the diversity of instrument data being developed today both by NASA and international partner agencies and because multi-discipline science and practitioner communities expect to have access to all types of observational

  11. Transportation engine commercialization at Ballard Power Systems

    SciTech Connect

    Otto, N.C.; Howard, P.F.

    1996-12-31

    Ballard is adapting its leading fuel cell technology for transit bus engines in three phases. In the first phase, completed in 1993, Ballard developed and demonstrated a 125 HP fuel cell engine in a 32-foot light duty transit bus. This was the world`s first zero-emission vehicle (ZEV) powered completely by PEM fuel cells. The bus is a reliable, smooth performing vehicle that clearly established the viability of Ballard Fuel Cells for zero-emission transit bus operation. In the second phase, completed in 1995, Ballard refined its fuel cell technology, building a 275 HP fuel cell engine for a 40-foot heavy duty transit bus. The fuel cell engine fits in the existing engine compartment and meets the performance of a combustion powered vehicle, but with no pollution. In the third phase, small fleets of ZEV buses will be tested with Chicago Transit Authority and BC Transit. These test fleets will provide the performance, cost and reliability data necessary for commercial production. Commercial production of Ballard`s environmentally clean engines will begin in the 1998-1999 timeframe.

  12. Apparatus for sensor failure detection and correction in a gas turbine engine control system

    NASA Technical Reports Server (NTRS)

    Spang, H. A., III; Wanger, R. P. (Inventor)

    1981-01-01

    A gas turbine engine control system maintains a selected level of engine performance despite the failure or abnormal operation of one or more engine parameter sensors. The control system employs a continuously updated engine model which simulates engine performance and generates signals representing real time estimates of the engine parameter sensor signals. The estimate signals are transmitted to a control computational unit which utilizes them in lieu of the actual engine parameter sensor signals to control the operation of the engine. The estimate signals are also compared with the corresponding actual engine parameter sensor signals and the resulting difference signals are utilized to update the engine model. If a particular difference signal exceeds specific tolerance limits, the difference signal is inhibited from updating the model and a sensor failure indication is provided to the engine operator.

  13. New engineering systems for mobility

    NASA Technical Reports Server (NTRS)

    Keller, T. L.; Kelvin, A.

    1974-01-01

    Aerospace technology transfer and a systems integration approach are considered in the development of a transportation system for the handicapped. The basic vehicle design includes a slide-out boarding ramp and wheelchair accommodations.

  14. QuadraLink engine system control for gen-sets and compressors

    SciTech Connect

    Anon.

    1995-07-01

    Woodward`s new QuadraLink distributed control system (DCS) for engine generator set and pipeline applications is designed as a creative solution to place engine system control directly in the user`s hands. For both new or existing power generation and large-bore gas pipeline engine installations, the QuadraLink system uses a powerful 32-bit multifunctional hardware and software system to perform important engine control, sequencing, and monitoring tasks. This paper describes the design, specifications and applications.

  15. Tank waste remediation system systems engineering management plan

    SciTech Connect

    Peck, L.G.

    1998-01-08

    This Systems Engineering Management Plan (SEMP) describes the Tank Waste Remediation System (TWRS) implementation of the US Department of Energy (DOE) systems engineering policy provided in 97-IMSD-193. The SEMP defines the products, process, organization, and procedures used by the TWRS Project to implement the policy. The SEMP will be used as the basis for tailoring the systems engineering applications to the development of the physical systems and processes necessary to achieve the desired end states of the program. It is a living document that will be revised as necessary to reflect changes in systems engineering guidance as the program evolves. The US Department of Energy-Headquarters has issued program management guidance, DOE Order 430. 1, Life Cycle Asset Management, and associated Good Practice Guides that include substantial systems engineering guidance.

  16. Gate engineered performance of single molecular transistor

    NASA Astrophysics Data System (ADS)

    Ray, S. J.

    2016-05-01

    The operation, performance and electrostatics of multigated Single Molecular Transistor (SMT) devices are investigated using first-principles based density functional theory calculations for planar (pentacene) and non-planar (sucrose) molecules as islands. It has been found that the incorporation of larger numbers of gates allows enhanced electrostatic control in the SMT operation which has been quantified from the energy calculations and estimation of the gate capacitances. The effect of multiple gates is more dominant for a non-planar molecule than a planar molecule within an SMT which indicates the usefulness of such multi-gate architectures for future nanoelectronic devices.

  17. Engineering system co-design with limited plant redesign

    NASA Astrophysics Data System (ADS)

    Allison, James T.

    2014-02-01

    Rather than designing engineering systems from the ground up, engineers often redesign strategic portions of existing systems to accommodate emerging needs. In the redesign of mechatronic systems, engineers typically seek to meet the requirements of a new application via control redesign only, but this is often insufficient and physical system (plant) design changes must be explored. Here, an integrated approach is presented for the redesign of mechatronic systems involving partial plant redesign that avoids costly complete redesign. Candidate plant modifications are identified using sensitivity analysis, and then an optimization problem is solved that minimizes redesign cost while satisfying system requirements. This formal methodology for Plant-Limited Co-Design (PLCD) is demonstrated using a robotic manipulator design problem. The PLCD result costs significantly less than the full redesign, and parametric studies illustrate the tradeoff between redesign cost and performance. It is shown that the proposed sensitivity analysis results in the lowest cost limited redesign.

  18. High Performance Work Systems and Firm Performance.

    ERIC Educational Resources Information Center

    Kling, Jeffrey

    1995-01-01

    A review of 17 studies of high-performance work systems concludes that benefits of employee involvement, skill training, and other high-performance work practices tend to be greater when new methods are adopted as part of a consistent whole. (Author)

  19. Cognitive engineering models in space systems

    NASA Technical Reports Server (NTRS)

    Mitchell, Christine M.

    1993-01-01

    NASA space systems, including mission operations on the ground and in space, are complex, dynamic, predominantly automated systems in which the human operator is a supervisory controller. Models of cognitive functions in complex systems are needed to describe human performance and form the theoretical basis of operator workstation design, including displays, controls, and decision aids. Currently, there several candidate modeling methodologies. They include the Rasmussen abstraction/aggregation hierarchy and decision ladder, the goal-means network, the problem behavior graph, and the operator function model. The research conducted under the sponsorship of this grant focuses on the extension of the theoretical structure of the operator function model and its application to NASA Johnson mission operations and space station applications. The initial portion of this research consists of two parts. The first is a series of technical exchanges between NASA Johnson and Georgia Tech researchers. The purpose is to identify candidate applications for the current operator function model; prospects include mission operations and the Data Management System Testbed. The second portion will address extensions of the operator function model to tailor it to the specific needs of Johnson applications. At this point, we have accomplished two things. During a series of conversations with JSC researchers, we have defined the technical goal of the research supported by this grant to be the structural definition of the operator function model and its computer implementation, OFMspert. Both the OFM and OFMspert have matured to the point that they require infrastructure to facilitate use by researchers not involved in the evolution of the tools. The second accomplishment this year was the identification of the Payload Deployment and Retrieval System (PDRS) as a candidate system for the case study. In conjunction with government and contractor personnel in the Human-Computer Interaction Lab

  20. Thermoelectric system for an engine

    DOEpatents

    Mcgilvray, Andrew N.; Vachon, John T.; Moser, William E.

    2010-06-22

    An internal combustion engine that includes a block, a cylinder head having an intake valve port and exhaust valve port formed therein, a piston, and a combustion chamber defined by the block, the piston, and the head. At least one thermoelectric device is positioned within either or both the intake valve port and the exhaust valve port. Each of the valves is configured to move within a respective intake and exhaust valve port thereby causing said valves to engage the thermoelectric devices resulting in heat transfer from the valves to the thermoelectric devices. The intake valve port and exhaust valve port are configured to fluidly direct intake air and exhaust gas, respectively, into the combustion chamber and the thermoelectric device is positioned within the intake valve port, and exhaust valve port, such that the thermoelectric device is in contact with the intake air and exhaust gas.

  1. Dynamic Performance of High Bypass Ratio Turbine Engines With Water Ingestion

    NASA Technical Reports Server (NTRS)

    Murthy, S. N. B.

    1996-01-01

    The research on dynamic performance of high bypass turbofan engines includes studies on inlets, turbomachinery and the total engine system operating with air-water mixture; the water may be in vapor, droplet, or film form, and their combinations. Prediction codes (WISGS, WINCOF, WINCOF-1, WINCLR, and Transient Engine Performance Code) for performance changes, as well as changes in blade-casing clearance, have been established and demonstrated in application to actual, generic engines. In view of the continuous changes in water distribution in turbomachinery, the performance of both components and the total engine system must be determined in a time-dependent mode; hence, the determination of clearance changes also requires a time-dependent approach. In general, the performance and clearances changes cannot be scaled either with respect to operating or ingestion conditions. Removal of water prior to phase change is the most effective means of avoiding ingestion effects. Sufficient background has been established to perform definitive, full scale tests on a set of components and a complete engine to establish engine control and operability with various air-water vapor-water mixtures.

  2. Aero-acoustic performance comparison of core engine noise suppressors on NASA quiet engine C

    NASA Technical Reports Server (NTRS)

    Bloomer, H. E.; Schaefer, J. W.

    1977-01-01

    The relative aero-acoustic effectiveness of two core engine suppressors, a contractor-designed suppressor delivered with the Quiet Engine, and a NASA-designed suppressor was evaluated. The NASA suppressor was tested with and without a splitter making a total of three configurations being reported in addition to the baseline hardwall case. The aerodynamic results are presented in terms of tailpipe pressure loss, corrected net thrust, and corrected specific fuel consumption as functions of engine power setting. The acoustic results are divided into duct and far-field acoustic data. The NASA-designed core suppressor did the better job of suppressing aft end noise, but the splitter associated with it caused a significant engine performance penality. The NASA core suppressor without the spltter suppressed most of the core noise without any engine performance penalty.

  3. Aero-acoustic performance comparison of core engine noise suppressors on NASA quiet engine 'C'

    NASA Technical Reports Server (NTRS)

    Bloomer, H. E.; Schaefer, J. W.

    1977-01-01

    The purpose of the experimental program reported herein was to evaluate and compare the relative aero-acoustic effectiveness of two core engine suppressors, a contractor-designed suppressor delivered with the Quiet Engine, and a NASA-designed suppressor, designed and built subsequently. The NASA suppressor was tested with and without a splitter making a total of three configurations being reported in addition to the baseline hardwall case. The aerodynamic results are presented in terms of tailpipe pressure loss, corrected net thrust, and corrected specific fuel consumption as functions of engine power setting. The acoustic results are divided into duct and far-field acoustic data. The NASA-designed core suppressor did the better job of suppressing aft end noise, but the splitter associated with it caused a significant engine performance penalty. The NASA core suppressor without the splitter suppressed most of the core noise without any engine performance penalty.

  4. Reusable rocket engine turbopump health management system

    NASA Astrophysics Data System (ADS)

    Surko, Pamela

    1994-10-01

    A health monitoring expert system software architecture has been developed to support condition-based health monitoring of rocket engines. Its first application is in the diagnosis decisions relating to the health of the high pressure oxidizer turbopump (HPOTP) of Space Shuttle Main Engine (SSME). The post test diagnostic system runs off-line, using as input the data recorded from hundreds of sensors, each running typically at rates of 25, 50, or .1 Hz. The system is invoked after a test has been completed, and produces an analysis and an organized graphical presentation of the data with important effects highlighted. The overall expert system architecture has been developed and documented so that expert modules analyzing other line replaceable units may easily be added. The architecture emphasizes modularity, reusability, and open system interfaces so that it may be used to analyze other engines as well.

  5. Reusable Rocket Engine Turbopump Health Management System

    NASA Technical Reports Server (NTRS)

    Surko, Pamela

    1994-01-01

    A health monitoring expert system software architecture has been developed to support condition-based health monitoring of rocket engines. Its first application is in the diagnosis decisions relating to the health of the high pressure oxidizer turbopump (HPOTP) of Space Shuttle Main Engine (SSME). The post test diagnostic system runs off-line, using as input the data recorded from hundreds of sensors, each running typically at rates of 25, 50, or .1 Hz. The system is invoked after a test has been completed, and produces an analysis and an organized graphical presentation of the data with important effects highlighted. The overall expert system architecture has been developed and documented so that expert modules analyzing other line replaceable units may easily be added. The architecture emphasizes modularity, reusability, and open system interfaces so that it may be used to analyze other engines as well.

  6. A new generation of high performance engines for spacecraft propulsion

    NASA Technical Reports Server (NTRS)

    Rosenberg, Sanders D.; Schoenman, Leonard

    1991-01-01

    Experimental data validating advanced engine designs at three thrust levels (5, 15, and 100 lbF) is presented. All of the three engine designs considered employ a Moog bipropellant torque motor valve, platelet injector design, and iridium-lined rhenium combustion chamber. Attention is focused on the performance, robustness, duration, and flexibility characteristics of the engines. It is noted that the 5- and 15-lbF thrust engines can deliver a steady state specific impulse in excess of 310 lbF-sec/lbm at an area ratio of 150:1, while the 150-lbF thrust engines deliver a steady state specific impulse of 320 lbF-sec/lbm at an area ratio of 250:1. The hot-fire test results reveal specific impulse improvements of 15 to 25 sec over conventional fuel film cooled columbium chamber designs while operating at maximum chamber temperatures.

  7. Performance of a 300-horsepower Hispano-Suiza airplane engine

    NASA Technical Reports Server (NTRS)

    Sparrow, S W; White, H S

    1921-01-01

    The National Bureau of Standards tested a 300-horsepower Hispano-Suiza engine to determine the characteristic performance of the engine at various altitudes. The engine was operated at the ground, at 25,000 feet, and at intermediate altitudes, both at full loads similar to those that would be imposed upon the engine at various speeds by a propeller whose normal full-load speed was 1,800 r.p.m. Friction horsepower also was determined in order that the mechanical efficiency of the engine might be calculated. From the test data there were computed the brake horsepower, brake mean effective pressure, specific fuel consumption, mixture ratio, jacket loss, exhaust loss, and thermal, mechanical, and volumetric efficiencies. A record of jacket water temperatures, oil temperatures, manifold pressures, etc., shows the conditions under which the test was made.

  8. F-15 digital electronic engine control system description

    NASA Technical Reports Server (NTRS)

    Myers, L. P.

    1984-01-01

    A digital electronic engine control (DEEC) was developed for use on the F100-PW-100 turbofan engine. This control system has full authority control, capable of moving all the controlled variables over their full ranges. The digital computational electronics and fault detection and accomodation logic maintains safe engine operation. A hydromechanical backup control (BUC) is an integral part of the fuel metering unit and provides gas generator control at a reduced performance level in the event of an electronics failure. The DEEC's features, hardware, and major logic diagrams are described.

  9. System Modeling of Gas Engine Driven Heat Pump

    SciTech Connect

    Mahderekal, Isaac; Shen, Bo; Vineyard, Edward

    2012-01-01

    To improve the system performance of the GHP, modeling and experimental study has been made by using desiccant system in cooling operation (particularly in high humidity operations) and suction line waste heat recovery to augment heating capacity and efficiency. The performance of overall GHP system has been simulated by using ORNL Modulating Heat Pump Design Software, which is used to predict steady-state heating and cooling performance of variable-speed vapor compression air-to-air heat pumps for a wide range of operational variables. The modeling includes: (1) GHP cycle without any performance improvements (suction liquid heat exchange and heat recovery) as a baseline (both in cooling and heating mode), (2) the GHP cycle in cooling mode with desiccant system regenerated by waste heat from engine incorporated, (3) GHP cycle in heating mode with heat recovery (recovered heat from engine). According to the system modeling results, by using desiccant system regenerated by waste heat from engine, the SHR can be lowered to 40%. The waste heat of the gas engine can boost the space heating efficiency by 25% in rated operating conditions.

  10. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  11. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  12. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  13. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  14. 40 CFR 91.307 - Engine cooling system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine cooling system. 91.307 Section...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.307 Engine cooling system. An engine cooling system is required with sufficient capacity to maintain the engine...

  15. SSME Automated Engine Calibration System (AECS)

    NASA Astrophysics Data System (ADS)

    Greene, William D.

    1992-07-01

    An algorithm is derived for the real-time calibration of the engine fuel flowmeter and the engine mixture ratio during Space Shuttle Main Engine (SSME) ground testing. Because currently used calibration methods are post-test operations, there exists no fail-safe way of predicting at what mixture ratio a planned test will run. It is proposed that the algorithm developed here be used as part of an Automated Engine Calibration System (AECS) which could ensure that nearly all SSME tests are run at the proper mixture ratio. In this way, AECS has the potential of increasing the efficiency of the SSME ground test program. In addition to the derivation of the algorithm, an overview of this calibration system is presented along with the list of test stand facility instrumentation necessary for AECS implementation.

  16. Spark ignition systems for internal combustion engines

    SciTech Connect

    Gol, G.; Hill, W.F.

    1980-08-26

    An internal combustion engine spark ignition system is provided which ensures that sparks are inhibited if the engine temperature exceeds a maximum safe level. The ignition circuit includes an input transistor which is switched on and off by an engine shaft transducer. The input transistor controls charging and discharging of a capacitor the voltage on which determines whether switching of the input transistor causes a spark to be produced via an output amplifier and ignition coil. A temperature sensing element determines both the rate at which the capacitor can charge and the final voltage to which it can be charged.

  17. Development of HIDEC adaptive engine control systems

    NASA Technical Reports Server (NTRS)

    Landy, R. J.; Yonke, W. A.; Stewart, J. F.

    1986-01-01

    The purpose of NASA's Highly Integrated Digital Electronic Control (HIDEC) flight research program is the development of integrated flight propulsion control modes, and the evaluation of their benefits aboard an F-15 test aircraft. HIDEC program phases are discussed, with attention to the Adaptive Engine Control System (ADECS I); this involves the upgrading of PW1128 engines for operation at higher engine pressure ratios and the production of greater thrust. ADECS II will involve the development of a constant thrust mode which will significantly reduce turbine operating temperatures.

  18. Internal performance predictions for Langley scramjet engine module

    NASA Technical Reports Server (NTRS)

    Pinckney, S. Z.

    1978-01-01

    A one dimensional theoretical method for the prediction of the internal performance of a scramjet engine is presented. The effects of changes in vehicle forebody flow parameters and characteristics on predicted thrust for the scramjet engine were evaluated using this method, and results are presented. A theoretical evaluation of the effects of changes in the scramjet engine's internal parameters is also presented. Theoretical internal performance predictions, in terms thrust coefficient and specific impulse, are provided for the scramjet engine for free stream Mach numbers of 5, 6, and 7 free stream dynamic pressure of 23,940 N/sq m forebody surface angles of 4.6 deg to 14.6 deg, and fuel equivalence ratio of 1.0.

  19. CF6-6D engine performance deterioration

    NASA Technical Reports Server (NTRS)

    Wulf, R. H.; Kramer, W. H.; Pass, J. E.; Smith, J. J.

    1980-01-01

    Cruise cockpit recordings and test cell performance data in conjunction with hardware inspection data from airline overhaul shops were analyzed to define the extent and magnitude of performance deterioration of the General Electric CF6-6D model engine. These studies successfully isolated short-term deterioration from the longer term, and defined areas where a significant reduction in aircraft energy requirements for the 1980's can be realized. Unrestored losses which remain after engine refurbishment represent over 70% of the loss at engine shop visit. Sixty-three percent of the unrestored losses are cost-effective to restore which could reduce fuel consumed by CF6-6D engines in 1980 by 10.9 million gallons.

  20. Performance Evaluation of a Data Validation System

    NASA Technical Reports Server (NTRS)

    Wong, Edmond (Technical Monitor); Sowers, T. Shane; Santi, L. Michael; Bickford, Randall L.

    2005-01-01

    Online data validation is a performance-enhancing component of modern control and health management systems. It is essential that performance of the data validation system be verified prior to its use in a control and health management system. A new Data Qualification and Validation (DQV) Test-bed application was developed to provide a systematic test environment for this performance verification. The DQV Test-bed was used to evaluate a model-based data validation package known as the Data Quality Validation Studio (DQVS). DQVS was employed as the primary data validation component of a rocket engine health management (EHM) system developed under NASA's NGLT (Next Generation Launch Technology) program. In this paper, the DQVS and DQV Test-bed software applications are described, and the DQV Test-bed verification procedure for this EHM system application is presented. Test-bed results are summarized and implications for EHM system performance improvements are discussed.

  1. User engineering: A new look at system engineering

    NASA Astrophysics Data System (ADS)

    McLaughlin, Larry L.

    1987-10-01

    User Engineering is a new System Engineering perspective responsible for defining and maintaining the user view of the system. Its elements are a process to guide the project and customer, a multidisciplinary team including hard and soft sciences, rapid prototyping tools to build user interfaces quickly and modify them frequently at low cost, and a prototyping center for involving users and designers in an iterative way. The main consideration is reducing the risk that the end user will not or cannot effectively use the system. The process begins with user analysis to produce cognitive and work style models, and task analysis to produce user work functions and scenarios. These become major drivers of the human computer interface design which is presented and reviewed as an interactive prototype by users. Feedback is rapid and productive, and user effectiveness can be measured and observed before the system is built and fielded. Requirements are derived via the prototype and baselined early to serve as an input to the architecture and software design.

  2. User engineering: A new look at system engineering

    NASA Technical Reports Server (NTRS)

    Mclaughlin, Larry L.

    1987-01-01

    User Engineering is a new System Engineering perspective responsible for defining and maintaining the user view of the system. Its elements are a process to guide the project and customer, a multidisciplinary team including hard and soft sciences, rapid prototyping tools to build user interfaces quickly and modify them frequently at low cost, and a prototyping center for involving users and designers in an iterative way. The main consideration is reducing the risk that the end user will not or cannot effectively use the system. The process begins with user analysis to produce cognitive and work style models, and task analysis to produce user work functions and scenarios. These become major drivers of the human computer interface design which is presented and reviewed as an interactive prototype by users. Feedback is rapid and productive, and user effectiveness can be measured and observed before the system is built and fielded. Requirements are derived via the prototype and baselined early to serve as an input to the architecture and software design.

  3. A study experiment of auto idle application in the excavator engine performance

    NASA Astrophysics Data System (ADS)

    Purwanto, Wawan; Maksum, Hasan; Putra, Dwi Sudarno; Azmi, Meri; Wahyudi, Retno

    2016-03-01

    The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

  4. CAD systems simplify engineering drawings

    SciTech Connect

    Holt, J.

    1986-10-01

    Computer assisted drafting systems, with today's technology, provide high-quality, timely drawings that can be justified by the lower costs for the final product. The author describes Exxon Pipeline Co.'s experience in deciding on hardware and software for a CAD system installation and the benefits effected by this procedure and equipment.

  5. Helping System Engineers Bridge the Peaks

    NASA Technical Reports Server (NTRS)

    Rungta, Neha; Tkachuk, Oksana; Person, Suzette; Biatek, Jason; Whalen, Michael W.; Castle, Joseph; Castle, JosephGundy-Burlet, Karen

    2014-01-01

    In our experience at NASA, system engineers generally follow the Twin Peaks approach when developing safety-critical systems. However, iterations between the peaks require considerable manual, and in some cases duplicate, effort. A significant part of the manual effort stems from the fact that requirements are written in English natural language rather than a formal notation. In this work, we propose an approach that enables system engineers to leverage formal requirements and automated test generation to streamline iterations, effectively "bridging the peaks". The key to the approach is a formal language notation that a) system engineers are comfortable with, b) is supported by a family of automated V&V tools, and c) is semantically rich enough to describe the requirements of interest. We believe the combination of formalizing requirements and providing tool support to automate the iterations will lead to a more efficient Twin Peaks implementation at NASA.

  6. Performance of the NEXT Engineering Model Power Processing Unit

    NASA Technical Reports Server (NTRS)

    Pinero, Luis R.; Hopson, Mark; Todd, Philip C.; Wong, Brian

    2007-01-01

    The NASA s Evolutionary Xenon Thruster (NEXT) project is developing an advanced ion propulsion system for future NASA missions for solar system exploration. An engineering model (EM) power processing unit (PPU) for the NEXT project was designed and fabricated by L-3 Communications under contract with NASA Glenn Research Center (GRC). This modular PPU is capable of processing up from 0.5 to 7.0 kW of output power for the NEXT ion thruster. Its design includes many significant improvements for better performance over the state-of-the-art PPU. The most significant difference is the beam supply which is comprised of six modules and capable of very efficient operation through a wide voltage range because of innovative features like dual controls, module addressing, and a high current mode. The low voltage power supplies are based on elements of the previously validated NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) PPU. The highly modular construction of the PPU resulted in improved manufacturability, simpler scalability, and lower cost. This paper describes the design of the EM PPU and the results of the bench-top performance tests.

  7. Long-term Performance of Engineered Barrier Systems (PEBS) - An International EURATOM Project on the Study and Testing of Engineered Barriers for the Final Disposal of HAW Using PEBS as an Example - 13299

    SciTech Connect

    Mente, M.

    2013-07-01

    The main aim of the PEBS project is to evaluate the sealing and barrier performance of the EBS over time, through development of a comprehensive approach involving experiments, model development, and consideration of the potential impacts on long-term safety functions. The experiments and models cover the full range of conditions, from initial emplacement of wastes (high heat generation and EBS re-saturation) through to later stage establishment of near steady state conditions, i.e. full re-saturation and thermal equilibrium with the host rock. These aspects will be integrated in a manner that will lead to greater certainty and thus greater confidence regarding the development from the initial transient state of the EBS to its long-term state, which provides the required isolation of the wastes. The work proposed within the project builds on existing knowledge and experience generated during recent years and supported by ongoing national and EC research programs. The project aims to provide a more complete description of the THM and THMC (thermo-hydro-mechanical- chemical) evolution of the EBS system, a more quantitative basis for relating the evolutionary behavior to the safety functions of the system, and a further clarification of the significance of residual uncertainties for long-term performance assessment. The importance of uncertainties arising from potential disagreement between the process models and the laboratory and in-situ experiments to be performed within PEBS, and their implications for an extrapolation of the results, will be reviewed, with particular emphasis on possible impacts on safety functions. In addition to the scientific-technical aims, the consortium will disseminate the basic findings to the broad scientific community within the EU, China and Japan, use expertise gained for public information purposes, and promote knowledge and technology transfer through training. (authors)

  8. Influence of secondary flow on aero-engine performance

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-bo; Wang, Zhan-xue; Liu, Zeng-wen

    2013-03-01

    In the actual design of turbofan engine with a high thrust-weight ratio, its secondary flow comes from the engine compression parts (fan or high pressure compressor), no matter the Fluidic Thrust Vector (FTV) nozzle is based on Shock Vectoring Controlling (SVC) or Throat Shift (TS). When the turbofan engine works in the state of thrust vector, regardless of the air bleeding from fan or high pressure compressor, the secondary flow have an impact on the components matching and engine performance. Therefore, the study of FTV technology in structurally fixed nozzle cannot just focus on a single nozzle, in the meantime, nozzle should be installed in the actual environment considering the synthesis of flow loss caused by bleed air (for example, bleed air from the compressor) and mixing of the main flow and secondary flow in the nozzle expansion section as well as effect on engine cycle and performance caused by the shockwave loss. Based on this consideration, this article proposes a component-based matching technique, which is applied via numerical simulation in the real environment. The main purpose of this article is research on the effect of FTV on the engine thermodynamic cycle and performance (thrust, fuel consumption and other parameters), considering the processes both air bleeds from fan/high pressure compressor, and it injects into the nozzle expansion section through the holes / slot.

  9. A Framework for Performing V&V within Reuse-Based Software Engineering

    NASA Technical Reports Server (NTRS)

    Addy, Edward A.

    1996-01-01

    Verification and validation (V&V) is performed during application development for many systems, especially safety-critical and mission-critical systems. The V&V process is intended to discover errors, especially errors related to critical processing, as early as possible during the development process. Early discovery is important in order to minimize the cost and other impacts of correcting these errors. In order to provide early detection of errors, V&V is conducted in parallel with system development, often beginning with the concept phase. In reuse-based software engineering, however, decisions on the requirements, design and even implementation of domain assets can be made prior to beginning development of a specific system. In this case, V&V must be performed during domain engineering in order to have an impact on system development. This paper describes a framework for performing V&V within architecture-centric, reuse-based software engineering. This framework includes the activities of traditional application-level V&V, and extends these activities into domain engineering and into the transition between domain engineering and application engineering. The framework includes descriptions of the types of activities to be performed during each of the life-cycle phases, and provides motivation for the activities.

  10. Quiet Clean Short-haul Experimental Engine (QCSEE) Under-The-Wing (UTW) engine composite nacelle test report. Volume 1: Summary, aerodynamic and mechanical performance

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The performance test results of the final under-the-wing engine configuration are presented. One hundred and six hours of engine operation were completed, including mechanical and performance checkout, baseline acoustic testing with a bellmouth inlet, reverse thrust testing, acoustic technology tests, and limited controls testing. The engine includes a variable pitch fan having advanced composite fan blades and using a ball-spline pitch actuation system.

  11. Systems Engineering of Coast Guard Aviator Training.

    ERIC Educational Resources Information Center

    Hall, Eugene R.; Caro, Paul W.

    This paper describes a total-program application of the systems engineering concept of the U.S. Coast Guard aviation training programs. The systems approach used treats all aspects of the training to produce the most cost-effective integration of academic, synthetic, and flight training for the production of graduate Coast Guard aviators. The…

  12. Engineering the System and Technical Integration

    NASA Technical Reports Server (NTRS)

    Blair, J. C.; Ryan, R. S.; Schutzenhofer, L. A.

    2011-01-01

    Approximately 80% of the problems encountered in aerospace systems have been due to a breakdown in technical integration and/or systems engineering. One of the major challenges we face in designing, building, and operating space systems is: how is adequate integration achieved for the systems various functions, parts, and infrastructure? This Contractor Report (CR) deals with part of the problem of how we engineer the total system in order to achieve the best balanced design. We will discuss a key aspect of this question - the principle of Technical Integration and its components, along with management and decision making. The CR will first provide an introduction with a discussion of the Challenges in Space System Design and meeting the challenges. Next is an overview of Engineering the System including Technical Integration. Engineering the System is expanded to include key aspects of the Design Process, Lifecycle Considerations, etc. The basic information and figures used in this CR were presented in a NASA training program for Program and Project Managers Development (PPMD) in classes at Georgia Tech and at Marshall Space Flight Center (MSFC). Many of the principles and illustrations are extracted from the courses we teach for MSFC.

  13. Systems engineering and integration: Advanced avionics laboratories

    NASA Technical Reports Server (NTRS)

    1990-01-01

    In order to develop the new generation of avionics which will be necessary for upcoming programs such as the Lunar/Mars Initiative, Advanced Launch System, and the National Aerospace Plane, new Advanced Avionics Laboratories are required. To minimize costs and maximize benefits, these laboratories should be capable of supporting multiple avionics development efforts at a single location, and should be of a common design to support and encourage data sharing. Recent technological advances provide the capability of letting the designer or analyst perform simulations and testing in an environment similar to his engineering environment and these features should be incorporated into the new laboratories. Existing and emerging hardware and software standards must be incorporated wherever possible to provide additional cost savings and compatibility. Special care must be taken to design the laboratories such that real-time hardware-in-the-loop performance is not sacrificed in the pursuit of these goals. A special program-independent funding source should be identified for the development of Advanced Avionics Laboratories as resources supporting a wide range of upcoming NASA programs.

  14. NREL PV System Performance and Standards Technical Progress

    SciTech Connect

    Osterwald, C. R.

    2005-01-01

    This paper presents a brief overview of the status and accomplishments during Fiscal Year (FY)2004 of the Photovoltaic (PV) System Performance & Standards Subtask, which is part of PV Systems Engineering Project (a joint NREL-Sandia project).

  15. Heat engine development for solar thermal power systems

    NASA Technical Reports Server (NTRS)

    Pham, H. Q.; Jaffe, L. D.

    1981-01-01

    The technical status of three heat engines (Stirling, high-temperature Brayton, and Combined cycle) for use in solar thermal power systems is presented. Performance goals necessary to develop a system competitive with conventional power requirements include an external heated engine output less than 40 kW, and efficiency power conversion subsystem at least 40% at rated output, and a half-power efficiency of at least 37%. Results show that the Stirling engine can offer a 39% efficiency with 100 hours of life, and a 20% efficiency with 10,000 hours of life, but problems with seals and heater heads exist. With a demonstrated efficiency near 31% at 1500 F and a minimum lifetime of 100,000 hours, the Brayton engine does not offer sufficient engine lifetime, efficiency, and maintenance for solar thermal power systems. Examination of the Rankine bottoming cycle of the Combined cycle engine reveals a 30 year lifetime, but a low efficiency. Additional development of engines for solar use is primarily in the areas of components to provide a long lifetime, high reliability, and low maintenance (no more than $0.001/kW-hr).

  16. Engineering development of coal-fired high performance power systems, Phases 2 and 3. Quarterly progress report, October 1--December 31, 1996. Final report

    SciTech Connect

    1996-12-31

    The goals of this program are to develop a coal-fired high performance power generation system (HIPPS) by the year 2000 that is capable of: {gt} 47% efficiency (HHV); NO{sub x}, SO{sub x}, and particulates {gt} 10% NSPS; coal providing {ge} 65% of heat input; all sold wastes benign; and cost of electricity 90% of present plant. Work reported herein is from Task 1.3 HIPPS Commercial Plant Design, Task 2,2 HITAF Air Heater, and Task 2.4 Duct Heater Design. The impact on cycle efficiency from the integration of various technology advances is presented. The criteria associated with a commercial HIPPS plant design as well as possible environmental control options are presented. The design of the HITAF air heaters, both radiative and convective, is the most critical task in the program. In this report, a summary of the effort associated with the radiative air heater designs that have been considered is provided. The primary testing of the air heater design will be carried out in the UND/EERC pilot-scale furnace; progress to date on the design and construction of the furnace is a major part of this report. The results of laboratory and bench scale activities associated with defining slag properties are presented. Correct material selection is critical for the success of the concept; the materials, both ceramic and metallic, being considered for radiant air heater are presented. The activities associated with the duct heater are also presented.

  17. Engine System Model Development for Nuclear Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Nelson, Karl W.; Simpson, Steven P.

    2006-01-01

    In order to design, analyze, and evaluate conceptual Nuclear Thermal Propulsion (NTP) engine systems, an improved NTP design and analysis tool has been developed. The NTP tool utilizes the Rocket Engine Transient Simulation (ROCETS) system tool and many of the routines from the Enabler reactor model found in Nuclear Engine System Simulation (NESS). Improved non-nuclear component models and an external shield model were added to the tool. With the addition of a nearly complete system reliability model, the tool will provide performance, sizing, and reliability data for NERVA-Derived NTP engine systems. A new detailed reactor model is also being developed and will replace Enabler. The new model will allow more flexibility in reactor geometry and include detailed thermal hydraulics and neutronics models. A description of the reactor, component, and reliability models is provided. Another key feature of the modeling process is the use of comprehensive spreadsheets for each engine case. The spreadsheets include individual worksheets for each subsystem with data, plots, and scaled figures, making the output very useful to each engineering discipline. Sample performance and sizing results with the Enabler reactor model are provided including sensitivities. Before selecting an engine design, all figures of merit must be considered including the overall impacts on the vehicle and mission. Evaluations based on key figures of merit of these results and results with the new reactor model will be performed. The impacts of clustering and external shielding will also be addressed. Over time, the reactor model will be upgraded to design and analyze other NTP concepts with CERMET and carbide fuel cores.

  18. HIDEC adaptive engine control system flight evaluation results

    NASA Technical Reports Server (NTRS)

    Yonke, W. A.; Landy, R. J.; Stewart, J. F.

    1987-01-01

    An integrated flight propulsion control mode, the Adaptive Engine Control System (ADECS), has been developed and flight tested on an F-15 aircraft as part of the NASA Highly Integrated Digital Electronic Control program. The ADECS system realizes additional engine thrust by increasing the engine pressure ratio (EPR) at intermediate and afterburning power, with the amount of EPR uptrim modulated using a predictor scheme for angle-of-attack and sideslip angle. Substantial improvement in aircraft and engine performance was demonstrated, with a 16 percent rate of climb increase, a 14 percent reduction in time to climb, and a 15 percent reduction in time to accelerate. Significant EPR uptrim capability was found with angles-of-attack up to 20 degrees.

  19. Integrated modeling and systems engineering for the Thirty Meter Telescope

    NASA Astrophysics Data System (ADS)

    Angeli, George Z.; Vogiatzis, Konstantinos; MacMynowski, Doug; Seo, Byoung-Joon; Nissly, Carl; Troy, Mitchell; Cho, Myung

    2011-09-01

    Modeling is an integral part of systems engineering. It is utilized in requirement validation, system verification, as well as for supporting design trade studies. Modeling highly complex systems poses particular challenges, including the definition and interpretation of system performance, and the combined evaluation of physical processes spanning a wide range of time frames. Our solution is based on statistical interpretation of system performance and a unique image quality metric developed by TMT. The Stochastic Framework and Point Source Sensitivity allow us to properly estimate and combine the optical effects of various disturbances and telescope imperfections.

  20. Reliability studies of Integrated Modular Engine system designs

    NASA Technical Reports Server (NTRS)

    Hardy, Terry L.; Rapp, Douglas C.

    1993-01-01

    A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.