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Sample records for main engine high

  1. Test results of the highly instrumented Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Mcconnaughey, H. V.; Leopard, J. L.; Lightfoot, R. M.

    1992-01-01

    Test results of a highly instrumented Space Shuttle Main Engine (SSME) are presented. The instrumented engine, when combined with instrumented high pressure turbopumps, contains over 750 special measurements, including flowrates, pressures, temperatures, and strains. To date, two different test series, accounting for a total of sixteen tests and 1,667 seconds, have been conducted with this engine. The first series, which utilized instrumented turbopumps, characterized the internal operating environment of the SSME for a variety of operating conditions. The second series provided system-level validation of a high pressure liquid oxygen turbopump that had been retrofitted with a fluid-film bearing in place of the usual pump-end ball bearings. Major findings from these two test series are highlighted in this paper. In addition, comparisons are made between model predictions and measured test data.

  2. The Calibrations of Space Shuttle Main Engines High Pressure Transducers

    NASA Technical Reports Server (NTRS)

    Steward, Christopher S.

    1995-01-01

    Previously, high pressure transducers that were used on the Space Shuttles Main Engine (SSME) exhibited a severe drift after being tested on the SSME. The Experimental Testing Technology Division (ETTD) designed some new transducers that would not exhibit a severe drift over a short period of time. These transducers were calibrated at the Test Bed at Marshall Space Flight Center (MSFC). After the high pressure transducers were calibrated, the transducers were placed on the SSME and fired. The transducers were then sent to the NASA LaRC to be recalibrated. The main objectives of the recalibrations was to make sure that the transducers possessed the same qualities as they did before they were fired on the SSME. Other objectives of the project were to determine the stability of the transducers and to determine whether the transducers exhibited a severe drift.

  3. Space Transportation Main Engine

    NASA Technical Reports Server (NTRS)

    Monk, Jan C.

    1992-01-01

    The topics are presented in viewgraph form and include the following: Space Transportation Main Engine (STME) definition, design philosophy, robust design, maximum design condition, casting vs. machined and welded forgings, operability considerations, high reliability design philosophy, engine reliability enhancement, low cost design philosophy, engine systems requirements, STME schematic, fuel turbopump, liquid oxygen turbopump, main injector, and gas generator. The major engine components of the STME and the Space Shuttle Main Engine are compared.

  4. High frequency data acquisition system for space shuttle main engine testing

    NASA Technical Reports Server (NTRS)

    Lewallen, Pat

    1987-01-01

    The high frequency data acquisition system developed for the Space Shuttle Main Engine (SSME) single engine test facility at the National Space Technology Laboratories is discussed. The real time system will provide engineering data for a complete set of SSME instrumentation (approx. 100 measurements) within 4 hours following engine cutoff, a decrease of over 48 hours from the previous analog tape based system.

  5. COBRA Main Engine Project

    NASA Technical Reports Server (NTRS)

    Snoddy, Jim; Sides, Steve; Lyles, Garry M. (Technical Monitor)

    2002-01-01

    The COBRA (CO-Optimized Booster for Reusable Applications) project include the following: 1. COBRA main engine project team. 2. COBRA and RLX cycles selected. 3. COBRA proto-type engine approach enables mission success. 4. COBRA provides quick, low cost demo of cycle and technologies. 5. COBRA cycle I risk reduction supports. 6. Achieving engine safety. 6. RLX cycle I risk reduction supports. 7. Flight qualification. 9. Life extension engine testing.

  6. Space Shuttle Main Engine instrumented High Pressure Oxidizer Turbopump technology test bed testing results summary

    NASA Technical Reports Server (NTRS)

    Koelbl, Mary E.

    1993-01-01

    This paper presents the test results from the Space Shuttle Main Engine (SSME) instrumented High Pressure Oxidizer Turbopump (HPOTP). The turbopump was tested on Engine 3001, a highly instrumented engine, in an effort to characterize the turbopump and the engine system. Seven tests, for a total duration of 766 seconds, were performed over a five month time period. The testing was performed at a wide variety of engine conditions. Changes in engine mixture ratio, power level, engine inlet oxidizer pressure, engine inlet fuel pressure, and engine start sequence were made. A discussion of all the HPOTP pressure and temperature data obtained are presented with comparisons to supporting analyses made where applicable. The effect of the various engine conditions on the measured data is addressed. This paper also discusses the challenges that were overcome to obtain the data. The significant instrumentation related problems encountered during the design, fabrication, and testing of this turbopump are summarized. Only those issues that affected the data obtained or the instrumentation itself are discussed. The relevance of the data to other noninstrumented turbomachinery is outlined. Conclusions and recommendations resulting from the test series will be presented.

  7. Rotordynamics analysis of the Space Shuttle main engine high-pressure oxidizer pump

    NASA Technical Reports Server (NTRS)

    Rowan, B. F.

    1980-01-01

    This study describes the rotordynamics analysis of the Space Shuttle Main Engine (SSME) high-pressure oxidizer turbopump. Modal synthesis methods were used to account for the complex coupling of the pump and engine structure. Cross-coupling elements effecting rotor stability were included in the analysis. Results of the analysis indicated that smaller bearing clearances and a smooth turbine interstage seal would result in longer bearing life and improved stability. Subsequent testing with these design features has shown the same results.

  8. Space shuttle main engine controller

    NASA Technical Reports Server (NTRS)

    Mattox, R. M.; White, J. B.

    1981-01-01

    A technical description of the space shuttle main engine controller, which provides engine checkout prior to launch, engine control and monitoring during launch, and engine safety and monitoring in orbit, is presented. Each of the major controller subassemblies, the central processing unit, the computer interface electronics, the input electronics, the output electronics, and the power supplies are described and discussed in detail along with engine and orbiter interfaces and operational requirements. The controller represents a unique application of digital concepts, techniques, and technology in monitoring, managing, and controlling a high performance rocket engine propulsion system. The operational requirements placed on the controller, the extremely harsh operating environment to which it is exposed, and the reliability demanded, result in the most complex and rugged digital system ever designed, fabricated, and flown.

  9. Structural Evaluation of a Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump Turbine Blade

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali

    1996-01-01

    Thermal and structural finite-element analyses were performed on the first high pressure fuel turbopump turbine blade of the space shuttle main engine (SSME). A two-dimensional (2-D) finite-element model of the blade and firtree disk attachment was analyzed using the general purpose MARC (finite-element) code. The loading history applied is a typical test stand engine cycle mission, which consists of a startup condition with two thermal spikes, a steady state and a shutdown transient. The blade material is a directionally solidified (DS) Mar-M 246 alloy, the blade rotor is forged with waspalloy material. Thermal responses under steady-state and transient conditions were calculated. The stresses and strains under the influence of mechanical and thermal loadings were also determined. The critical regions that exhibited high stresses and severe localized plastic deformation were the blade-rotor gaps.

  10. High pressure oxygen turbopump bearing cage stability analyses. [space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Merriman, T. L.; Kannel, J. W.

    1984-01-01

    The low service life of the high pressure oxygen turbopump (HPOTP) bearings used in the space shuttle main engine was examined by use of the Battelle "BASDAP' bearing computer stability model. The dynamic instability of the bearing cage resulted in excessive wear and eventual failure of the unit. By maintaining a cage/race clearance of no more than 0.25 millimeters (0.010 inches), ball/pocket clearance of no less than 0.54 millimeters (0.025 inches), dynamic balancing of the cages, and maintaining adequate lubricant films between the balls and races, cage instability and subsequent bearing degradation can be reduced.

  11. Rotordynamic Characteristics of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine)

    NASA Technical Reports Server (NTRS)

    Childs, D. W.

    1984-01-01

    Rotational stability of turbopump components in the space shuttle main engine was studied via analysis of component and structural dynamic models. Subsynchronous vibration caused unacceptable migration of the rotor/housing unit with unequal load sharing of the synchronous bearings that resulted in the failure of the High Pressure Oxygen Turbopump. Linear analysis shows that a shrouded inducer eliminates the second critical speed and the stability problem, a stiffened rotor improves the rotordynamic characteristics of the turbopump, and installing damper boost/impeller seals reduces bearing loads. Nonlinear analysis shows that by increasing the "dead band' clearances, a marked reduction in peak bearing loads occurs.

  12. Space shuttle main engine high pressure fuel pump aft platform seal cavity flow analysis

    NASA Technical Reports Server (NTRS)

    Lowry, S. A.; Keeton, L. W.

    1987-01-01

    A general purpose, three-dimensional computational fluid dynamics code named PHOENICS, developed by CHAM Inc., is used to model the flow in the aft-platform seal cavity in the high pressure fuel pump of the space shuttle main engine. The model is used to predict the temperatures, velocities, and pressures in the cavity for six different sets of boundary conditions. The results are presented as input for further analysis of two known problems in the region, specifically: erratic pressures and temperatures in the adjacent coolant liner cavity and cracks in the blade shanks near the outer diameter of the aft-platform seal.

  13. An analysis of pump cavitation damage. [Space Shuttle main engine high pressure oxidizer turbopump

    NASA Technical Reports Server (NTRS)

    Brophy, M. C.; Stinebring, D. R.; Billet, M. L.

    1985-01-01

    The cavitation assessment for the space shuttle main engine high pressure oxidizer turbopump is documented. A model of the flow through the pump was developed. Initially, a computational procedure was used to analyze the flow through the inlet casing including the prediction of wakes downstream of the casing vanes. From these flow calculations, cavitation patterns on the inducer blades were approximated and the damage rate estimated. The model correlates the heavy damage on the housing and over the inducer with unsteady blade surface cavitation. The unsteady blade surface cavitation is due to the large incidence changes caused by the wakes of the upstream vanes. Very high cavitation damage rates are associated with this type of cavitation. Design recommendations for reducing the unsteady cavitation include removing the set of vanes closest to the inducer and modifying the remaining vanes.

  14. A study of pump cavitation damage. [space shuttle main engine high pressure oxidizer turbopump

    NASA Technical Reports Server (NTRS)

    Brophy, M. C.; Stinebring, D. R.; Billet, M. L.

    1983-01-01

    The cavitation assessment for the space shuttle main engine high pressure oxidizer turbopump is documented. A model of the flow through the pump was developed. Initially, a computational procedure was used to analyze the flow through the inlet casing including the prediction of wakes downstream of the casing vanes. From these flow calculations, cavitation patterns on the inducer blades were approximated and the damage rate estimated. The model correlates the heavy damage on the housing and over the inducer with unsteady blade surface cavitation. The unsteady blade surface cavitation is due to the large incidence changes caused by the wakes of the upstream vanes. Very high cavitation damage rates are associated with this type of cavitation. Design recommendations for reducing the unsteady cavitation include removing the set of vanes closest to the inducer and modifying the remaining vanes.

  15. Analysis of cavitation damage on the Space Shuttle main engine high pressure oxidizer turbopump

    NASA Technical Reports Server (NTRS)

    Stinebring, D. R.

    1985-01-01

    The performance of the Space Shuttle Main Engines (SSME) has met or exceeded specifications. However, the durability for selected components has not met the desired lifetime criteria. Thus, the High-Pressure Oxidizer Turbopump (HPOTP) has experienced cavitation erosion problems in a number of locations in the pump. An investigation was conducted, taking into account an analysis of the cavitation damage, the development of a flow model for the pump, and the recommendation of design changes which would increase the life expectancy of the unit. The present paper is concerned with the cavitation damage analysis. A model is presented which relates the heavy damage on the housing and over the inducer blades to unsteady blade surface cavitation. This cavitation occurs on the inducer blades in the wakes downstream of the pump inlet housing vanes.

  16. A model for the Space Shuttle Main Engine High Pressure Oxidizer Turbopump shaft seal system

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    1990-01-01

    A model of the High Pressure Oxidizer Turbopump (HPOTP) shaft seal system on the Space Shuttle Main Engine (SSME) is described. The model predicts the fluid properties and flow rates throughout this system for a number of conditions simulating failed seals. The results agree well with qualitative expectations and redline values but cannot be verified with actual data due to the lack thereof. The results indicate that each failure mode results in a unique distribution of properties throughout the seal system and can therefore be individually identified given the proper instrumentation. Furthermore, the detection process can be built on the principle of qualitative reasoning without the use of exact fluid property values. A simplified implementation of the model which does not include the slinger/labyrinth seal combination has been developed and will be useful for inclusion in a real-time diagnostic system.

  17. A model for the Space Shuttle Main Engine High Pressure Oxidizer Turbopump shaft seal system

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    1990-01-01

    A model of the High Pressure Oxidizer Turbopump (HPOTP) shaft seal system on the Space Shuttle Main Engine (SSME) is described. The model predicts the fluid properties and flow rates throughout this system for a number of conditions simulating failed seals. The results agree well with qualitative expectations and redline values but cannot be verified with actual data due to the lack thereof. The results indicate that each failure mode results in a unique distribution of properties throughout the seal system and can therefore be individually identified given the proper instrumentation. Furthermore, the detection process can be built on the principle of qualitative reasoning without the use of exact fluid property values. A simplified implementation of the model which does not include the slinger/labyrinth seal combination has been developed and will be useful for inclusion in a real-time diagnostic system.

  18. Vibration effects of the space shuttle main engine high pressure oxidizer turbopump bellows

    NASA Technical Reports Server (NTRS)

    Harp, J. A.

    1978-01-01

    A welded metal bellows was subjected to a series of vibration tests in a 400 psi oxygen environment to evaluate the effects of the bellows convolutes rubbing on the damper ring in the high pressure oxidizer turbopump of the space shuttle main engine. The bellows was subjected to approximately 2 million cycles at 0.007 in. double amplitude displacement during this series of tests, at a frequency of 400 Hz. Intrumentation of the test specimen revealed no significant heat buildup caused by the rubbing of the bellows convolutes on the damper ring. A final destruct test was made to determine if a fire would result if the bellows ruptured in the 400 psi oxygen environment, thus exposing a fresh metal surface. The vibration input was changed to 0.8 in. double amplitude displacement at 20 Hz to intentionally rupture the bellows. Failure occurred after 2.5 sec; no fire or heat buildup was encountered.

  19. Effect of flange bolt preload on Space Shuttle main engine high pressure oxidizer turbopump housing analysis

    NASA Technical Reports Server (NTRS)

    Min, J. B.; Johnston, L. M.; Czekalski, B.

    1991-01-01

    Cracks at the seal fillet flange and the strut pilot groove of primary turbine drain passage of the space shuttle main engine (SSME) high pressure oxidizer turbopump (HPOTP) were observed and reported. Stress information for critical structural components in the SSME under actual conditions is necessary for design and life prediction analysis. However, little information is available about the stress distribution at this location under various combinations of loadings and environments. Thus, a stress analysis was conducted to determine an influence of the various operation and installation loads on the stresses of the HPOTP main mounting flange. To do this, a 3-D finite element model of the HPOTP housing was generated. A fairly comfortable margin of stresses at the flange fillet with respect to the yield stress of Inconel 718 is shown. However, it was revealed that the bending stress arising from the housing flange bolt preloads could significantly affect the stress distribution at the strut pilot groove of primary turbine drain passage in the HPOTP housing. Consequently, the information obtained from the present 3-D analysis results should be useful in guiding the development of the SSME HPOTP.

  20. Space Shuttle Main Engine High Pressure Fuel Turbopump Turbine Blade Cracking

    NASA Technical Reports Server (NTRS)

    Lee, Henry

    1988-01-01

    The analytical results from two-dimensional (2D) and three-dimensional (3D) finite element model investigations into the cracking of Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) first- and second-stage turbine blades are presented. Specifically, the initiation causes for transverse cracks on the pressure side of the firststage blade fir tree lobes and face/corner cracks on the downstream fir tree face of the second-state blade are evaluated. Because the blade material, MAR-M-246 Hf (DS), is highly susceptible to hydrogen embrittlement in the -100 F to 400 F thermal environment, a steady-state condition (full power level = 109 percent) rather than a start-up or shut-down transient was considered to be the most likely candidate for generating a high-strain state in the fir tree areas. Results of the analyses yielded strain levels on both first- and second-stage blade fir tree regions that are of a magnitude to cause hydrogen assisted low cycle fatigue cracking. Also evident from the analysis is that a positive margin against fir tree cracking exists for the planned design modifications, which include shot peening for both first- and second-stage blade fir tree areas.

  1. Space Shuttle Era: Main Engines

    NASA Image and Video Library

    Producing 500,000 pounds of thrust from a package weighing only 7,500 pounds, the Space Shuttle Main Engines are one of the shining accomplishments of the shuttle program. The success did not come ...

  2. A model for the space shuttle main engine high pressure oxidizer turbopump shaft seal system

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    1990-01-01

    A simple static model is presented which solves for the flow properties of pressure, temperature, and mass flow in the Space Shuttle Main Engine pressure Oxidizer Turbopump Shaft Seal Systems. This system includes the primary and secondary turbine seals, the primary and secondary turbine drains, the helium purge seals and feed line, the primary oxygen drain, and the slinger/labyrinth oxygen seal pair. The model predicts the changes in flow variables that occur during and after failures of the various seals. Such information would be particularly useful in a post flight situation where processing of sensor information using this model could identify a particular seal that had experienced excessive wear. Most of the seals in the system are modeled using simple one dimensional equations which can be applied to almost any seal provided that the fluid is gaseous. A failure is modeled as an increase in the clearance between the shaft and the seal. Thus, the model does not attempt to predict how the failure process actually occurs (e.g., wear, seal crack initiation). The results presented were obtained using a FORTRAN implementation of the model running on a VAX computer. Solution for the seal system properties is obtained iteratively; however, a further simplified implementation (which does not include the slinger/labyrinth combination) was also developed which provides fast and reasonable results for most engine operating conditions. Results from the model compare favorably with the limited redline data available.

  3. Assessment of crack growth in a space shuttle main engine first-stage, high-pressure fuel turbopump blade

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali

    1993-01-01

    A two-dimensional finite element fracture mechanics analysis of a space shuttle main engine (SSME) turbine blade firtree was performed using the MARC finite element code. The analysis was conducted under combined effects of thermal and mechanical loads at steady-state conditions. Data from a typical engine stand cycle of the SSME were used to run a heat transfer analysis and, subsequently, a thermal structural fracture mechanics analysis. Temperature and stress contours for the firtree under these operating conditions were generated. High stresses were found at the firtree lobes where crack initiation was triggered. A life assessment of the firtree was done by assuming an initial and a final crack size.

  4. An expert system to analyze high frequency dependent data for the space shuttle main engine turbopumps

    NASA Technical Reports Server (NTRS)

    Garcia, Raul C., Jr.

    1987-01-01

    The prototype expert system ADDAMX identifies selected sinusoid frequencies from spectral data graphs as speed frequencies and harmonics from each turbopump, frequency feed through from one turbopump to another, frequencies generated by turbopump bearings, pseudo 3N for the phase 2 high pressure fuel turbopump, and electrical noise. ADDAMX does the analysis in an interactive or batch mode and the results can be displayed on the screen or hardcopy.

  5. Developing acceptance limits for measured bearing wear of the Space Shuttle Main Engine high pressure oxidizer turbopump

    NASA Technical Reports Server (NTRS)

    Genge, Gary G.

    1991-01-01

    The probabilistic design approach currently receiving attention for structural failure modes has been adapted for obtaining measured bearing wear limits in the Space Shuttle Main Engine high-pressure oxidizer turbopump. With the development of the shaft microtravel measurements to determine bearing health, an acceptance limit was neeed that protects against all known faiure modes yet is not overly conservative. This acceptance criteria limit has been successfully determined using probabilistic descriptions of preflight hardware geometry, empirical bearing wear data, mission requirements, and measurement tool precision as an input for a Monte Carlo simulation. The result of the simulation is a frequency distribution of failures as a function of preflight acceptance limits. When the distribution is converted into a reliability curve, a conscious risk management decision is made concerning the acceptance limit.

  6. Residual-flexibility corrections for transient modal rotordynamic models. [Space Shuttle main engine high pressure oxygen turbopump

    NASA Technical Reports Server (NTRS)

    Childs, D. W.; Bates, J. B., III

    1978-01-01

    A modal residual-flexibility approach due to Schwendler and MacNeal (1962) is adapted to account for the 'static' contribution of higher-frequency modes without requiring their integration. It is assumed that each rotor mode acts as a lightly damped second-order system. The additional accuracy provided by residual-flexibility corrections becomes progressively more important as a modal model's actual boundary conditions are forced to deviate from the boundary conditions used to define the rotor's original structural model (stiffness matrix) and its associated eigendata input to the transient modal model. An analysis of the high-pressure-oxygen turbopump of the Space Shuttle main engine shows that the residual-flexibility approach ensures a substantial improvement in accuracy for a relatively moderate increase in computer-time requirements.

  7. Space shuttle main engine vibration data base

    NASA Technical Reports Server (NTRS)

    Lewallen, Pat

    1987-01-01

    In order to evaluate Space Shuttle Main Engine (SSME) vibration data without having to constantly replay analog tapes, the SSME Vibration Data Base was developed. This data base contains data that have been digitized at a high sample rate for the entire test duration. It provides quick and efficient recall capabilities for numerious computation and display routines. The data base components are described as well as some of the compution and display features.

  8. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 3A: High pressure oxidizer turbo-pump preburner pump housing stress analysis report

    NASA Technical Reports Server (NTRS)

    Shannon, Robert V., Jr.

    1989-01-01

    The model generation and structural analysis performed for the High Pressure Oxidizer Turbopump (HPOTP) preburner pump volute housing located on the main pump end of the HPOTP in the space shuttle main engine are summarized. An ANSYS finite element model of the volute housing was built and executed. A static structural analysis was performed on the Engineering Analysis and Data System (EADS) Cray-XMP supercomputer

  9. Space shuttle main engine turbopump transducer

    NASA Astrophysics Data System (ADS)

    Peterson, T.

    Advances in liquid rocket engine technology were required to meet the life and reuseability criteria set by the Space Shuttle Program for the Space Shuttle Main Engines (SSME). To verify the SSME design life, extensive development testing and hardware inspection was required. Each SSME has four turbopumps which are used to pump propellant for combustion. One of these turbopumps which pumps liquid oxygen is the High Pressure Oxygen Turbopump (HPPTP). Using a two stage turbine, the HPCTP produces 29,410 horsepower to pump 69.6 pounds per second of liquid oxygen. One area of hardware inspection and testing to insure engine life and operation was in the area of the rocket engine turbopumps bearings. Bearing life is critical to the overall reusability of the HPOTP. After each development test of the SSME, inspection of many engine parts are made. During inspection of the HPOTP it was observed that some of the bearings in the pump were wearing excessively. The bearings in question were the number 3 and 4 bearings in the pump. To determine the cause of the wear, one HPOTP would be instrumented to monitor the bearing conditions.

  10. Space transportation main engine reliability and safety

    NASA Technical Reports Server (NTRS)

    Monk, Jan C.

    1991-01-01

    Viewgraphs are used to illustrate the reliability engineering and aerospace safety of the Space Transportation Main Engine (STME). A technology developed is called Total Quality Management (TQM). The goal is to develop a robust design. Reducing process variability produces a product with improved reliability and safety. Some engine system design characteristics are identified which improves reliability.

  11. Space transportation main engine cycle assessment process

    NASA Technical Reports Server (NTRS)

    Mcconnaughey, H. V.; Lyles, G. M.

    1991-01-01

    The Advanced Launch System (ALS) program selection process for a space transportation main engine (STME) power cycle is described in terms of the methodology employed. Low cost, robustness, and high reliability are the primary parameters for engine choice, suggesting simplicity of design and efficient fabrication methods as the crucial characteristics. An evaluation methodology is developed based on the Pugh (1981) process and the King (1989) matrices. The cycle configurations considered are the gas generator (GG), the closed expander, and the open expander. The cycle assessment team determined that the GG cycle is favored by most cycle discriminators, based on an assessment of the characteristics in terms of ALS goals. The lower development risk of the GG-cycle STME is consistent with the goals of the ALS program in terms of reliability and cost efficiency.

  12. Space transportation main engine cycle assessment process

    NASA Technical Reports Server (NTRS)

    Mcconnaughey, H. V.; Lyles, G. M.

    1991-01-01

    The Advanced Launch System (ALS) program selection process for a space transportation main engine (STME) power cycle is described in terms of the methodology employed. Low cost, robustness, and high reliability are the primary parameters for engine choice, suggesting simplicity of design and efficient fabrication methods as the crucial characteristics. An evaluation methodology is developed based on the Pugh (1981) process and the King (1989) matrices. The cycle configurations considered are the gas generator (GG), the closed expander, and the open expander. The cycle assessment team determined that the GG cycle is favored by most cycle discriminators, based on an assessment of the characteristics in terms of ALS goals. The lower development risk of the GG-cycle STME is consistent with the goals of the ALS program in terms of reliability and cost efficiency.

  13. Space shuttle main engine: Interactive design challenges

    NASA Technical Reports Server (NTRS)

    Mccarty, J. P.; Wood, B. K.

    1985-01-01

    The operating requirements established by NASA for the SSME were considerably more demanding than those for earlier rocket engines used in the military launch vehicles or Apollo program. The SSME, in order to achieve the high performance, low weight, long life, reusable objectives, embodied technical demands far in excess of its predecessor rocket engines. The requirements dictated the use of high combustion pressure and the staged combustion cycle which maximizes performance through total use of all propellants in the main combustion process. This approach presented a myriad of technical challenges for maximization of performance within attainable state of the art capabilities for operating pressures, operating temperatures and rotating machinery efficiencies. Controlling uniformity of the high pressure turbomachinery turbine temperature environment was a key challenge for thrust level and life capability demanding innovative engineering. New approaches in the design of the components were necessary to accommodate the multiple use, minimum maintenance objectives. Included were the use of line replaceable units to facilitate field maintenance automatic checkout and internal inspection capabilities.

  14. Space Shuttle Main Engine Test Firing

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A cloud of extremely hot steam boils out of the flame deflector at the A-1 test stand during a test firing of a Space Shuttle Main Engine (SSME) at the John C. Stennis Space Center, Hancock County, Mississippi.

  15. Space Shuttle Main Engine (SSME) Operational Capability

    NASA Technical Reports Server (NTRS)

    Benefield, Philip; Bradley, Doug

    2010-01-01

    Through the years of the Space Shuttle Main Engine (SSME) program the engine has evolved and operational capabilities have been demonstrated beyond the original Shuttle requirements. In an effort to enhance flight safety and demonstrate safety features and margins, engines have been analyzed and tested at many different operating points. Various studies through the years evaluating the SSME for different applications both as a boost stage and upper stage have also added insight into the overall operational characteristics of the engine and have further defined safety margins for the Shuttle application. This paper will summarize the operational characteristics of the SSME from the original design requirements to the expanded capabilities demonstrated through analysis, lab testing and especially "off-nominal" engine testing leading to an increased understanding of the engine operational characteristics and safety margins. Basic engine characteristics such as thrust, mixture ratio, propellant inlet conditions, system redundancy, etc. will be examined.

  16. Closeup View of the Space Shuttle Main Engine (SSME) 2044 ...

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

    Close-up View of the Space Shuttle Main Engine (SSME) 2044 mounted in a SSME Engine Handler in the SSME processing Facility at Kennedy Space Center. This view shows SSME 2044 with its expansion nozzle removed and an Engine Leak-Test Plug is set in the throat of the Main Combustion Chamber in the approximate center of the image, the insulated, High-Pressure Fuel Turbopump sits below that and the Low Pressure Oxidizer Turbopump Discharge Duct sits towards the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  17. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 4: High pressure fuel turbo-pump inlet housing analysis

    NASA Technical Reports Server (NTRS)

    Pool, Kirby V.

    1989-01-01

    The analysis performed on the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) inlet housings is summarized. Three DIAL finite element models were build to aid in assessing the structural life of the welds and fillets at the vanes. Complete results are given.

  18. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 3B: High pressure fuel turbo-pump preburner pump bearing assembly analysis

    NASA Technical Reports Server (NTRS)

    Power, Gloria B.; Violett, Rebeca S.

    1989-01-01

    The analysis performed on the High Pressure Oxidizer Turbopump (HPOTP) preburner pump bearing assembly located on the Space Shuttle Main Engine (SSME) is summarized. An ANSYS finite element model for the inlet assembly was built and executed. Thermal and static analyses were performed.

  19. The Space Shuttle Main Engine and its maintenance features

    NASA Technical Reports Server (NTRS)

    Wheelock, V. J.

    1973-01-01

    The Space Shuttle Main Engine (SSME) is a reusable, high-performance rocket engine being developed to satisfy the performance, life, reliability, and operational requirements of the Space Shuttle Orbiter. The design includes simple, low-cost maintenance features resulting from a viable maintainability program dedicated to minimizing engine cost per flight.

  20. Computational fluid dynamics analysis of Space Shuttle main engine multiple plume flows at high-altitude flight conditions

    NASA Technical Reports Server (NTRS)

    Dougherty, N. S.; Holt, J. B.; Liu, B. L.; Johnson, S. L.

    1992-01-01

    Computational fluid dynamics (CFD) analysis is providing verification of Space Shuttle flight performance details and is being applied to Space Shuttle Main Engine Multiple plume interaction flow field definition. Advancements in real-gas CFD methodology that are described have allowed definition of exhaust plume flow details at Mach 3.5 and 107,000 ft. The specific objective includes the estimate of flow properties at oblique shocks between plumes and plume recirculation into the Space Shuttle Orbiter base so that base heating and base pressure can be modeled accurately. The approach utilizes the Rockwell USA Real Gas 3-D Navier-Stokes (USARG3D) Code for the analysis. The code has multi-zonal capability to detail the geometry of the plumes based region and utilizes finite-rate chemistry to compute the plume expansion angle and relevant flow properties at altitude correctly. Through an improved definition of the base recirculation flow properties, heating, and aerodynamic design environments of the Space Shuttle Vehicle can be further updated.

  1. Computational fluid dynamics analysis of Space Shuttle main engine multiple plume flows at high-altitude flight conditions

    NASA Technical Reports Server (NTRS)

    Dougherty, N. S.; Holt, J. B.; Liu, B. L.; Johnson, S. L.

    1992-01-01

    Computational fluid dynamics (CFD) analysis is providing verification of Space Shuttle flight performance details and is being applied to Space Shuttle Main Engine Multiple plume interaction flow field definition. Advancements in real-gas CFD methodology that are described have allowed definition of exhaust plume flow details at Mach 3.5 and 107,000 ft. The specific objective includes the estimate of flow properties at oblique shocks between plumes and plume recirculation into the Space Shuttle Orbiter base so that base heating and base pressure can be modeled accurately. The approach utilizes the Rockwell USA Real Gas 3-D Navier-Stokes (USARG3D) Code for the analysis. The code has multi-zonal capability to detail the geometry of the plumes based region and utilizes finite-rate chemistry to compute the plume expansion angle and relevant flow properties at altitude correctly. Through an improved definition of the base recirculation flow properties, heating, and aerodynamic design environments of the Space Shuttle Vehicle can be further updated.

  2. Computational fluid dynamics analysis of Space Shuttle main engine multiple plume flows at high-altitude flight conditions

    NASA Astrophysics Data System (ADS)

    Dougherty, N. S.; Holt, J. B.; Liu, B. L.; Johnson, S. L.

    1992-07-01

    Computational fluid dynamics (CFD) analysis is providing verification of Space Shuttle flight performance details and is being applied to Space Shuttle Main Engine Multiple plume interaction flow field definition. Advancements in real-gas CFD methodology that are described have allowed definition of exhaust plume flow details at Mach 3.5 and 107,000 ft. The specific objective includes the estimate of flow properties at oblique shocks between plumes and plume recirculation into the Space Shuttle Orbiter base so that base heating and base pressure can be modeled accurately. The approach utilizes the Rockwell USA Real Gas 3-D Navier-Stokes (USARG3D) Code for the analysis. The code has multi-zonal capability to detail the geometry of the plumes based region and utilizes finite-rate chemistry to compute the plume expansion angle and relevant flow properties at altitude correctly. Through an improved definition of the base recirculation flow properties, heating, and aerodynamic design environments of the Space Shuttle Vehicle can be further updated.

  3. Identification of space shuttle main engine dynamics

    NASA Technical Reports Server (NTRS)

    Duyar, Ahmet; Guo, Ten-Huei; Merrill, Walter C.

    1989-01-01

    System identification techniques are used to represent the dynamic behavior of the Space Shuttle Main Engine. The transfer function matrices of the linearized models of both the closed loop and the open loop system are obtained by using the recursive maximum likelihood method.

  4. Space shuttle main engine computed tomography applications

    NASA Technical Reports Server (NTRS)

    Sporny, Richard F.

    1990-01-01

    For the past two years the potential applications of computed tomography to the fabrication and overhaul of the Space Shuttle Main Engine were evaluated. Application tests were performed at various government and manufacturer facilities with equipment produced by four different manufacturers. The hardware scanned varied in size and complexity from a small temperature sensor and turbine blades to an assembled heat exchanger and main injector oxidizer inlet manifold. The evaluation of capabilities included the ability to identify and locate internal flaws, measure the depth of surface cracks, measure wall thickness, compare manifold design contours to actual part contours, perform automatic dimensional inspections, generate 3D computer models of actual parts, and image the relationship of the details in a complex assembly. The capabilities evaluated, with the exception of measuring the depth of surface flaws, demonstrated the existing and potential ability to perform many beneficial Space Shuttle Main Engine applications.

  5. General view of a Space Shuttle Main Engine (SSME) mounted ...

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

    General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping around the right side and underneath the assembly, the High-Pressure Fuel Turbopump located on the lower left portion of the assembly, the Engine Controller and Main Fuel Valve Hydraulic Actuator located on the upper portion of the assembly and the Low-Pressure Oxidizer Turbopump Discharge Duct at the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  6. Closeup side view of Space Shuttle Main Engine (SSME) 2059 ...

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

    Close-up side view of Space Shuttle Main Engine (SSME) 2059 mounted in a SSME Engine Handler near the Drying Area in the High Bay section of the SSME Processing Facility. The prominent features of the SSME in this view are the hot-gas expansion nozzle extending from the approximate image center toward the image right. The main-engine components extend from the approximate image center toward image right until it meets up with the mount for the SSME Engine Handler. The engine is rotated to a position where the major components in the view are the Low-Pressure Fuel Turbopump Discharge Duct with reflective foil insulation on the upper side of the engine, the Low-Pressure Oxidizer Turbopump and its Discharge Duct on the right side of the engine assembly extending itself down and wrapping under the bottom side of the assembly to the High-Pressure Oxidizer Turbopump pump. The High-Pressure Oxidizer Turbopump Discharge Duct exists the turbopump and extends up to the top side of the assembly where it enters the main oxidizer valve. The sphere on the lower side of the engine assembly is an accumulator that is part of the SSMEs POGO suppression system. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  7. General view of a Space Shuttle Main Engine (SSME) mounted ...

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

    General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Oxidizer Turbopump Discharge Duct looping around the right side of the engine assembly then turning in and connecting to the High-Pressure Oxidizer Turbopump. The sphere in the approximate center of the assembly is the POGO System Accumulator, the Engine Controller is located on the bottom and slightly left of the center of the Engine Assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  8. Space shuttle main engine plume radiation model

    NASA Technical Reports Server (NTRS)

    Reardon, J. E.; Lee, Y. C.

    1978-01-01

    The methods are described which are used in predicting the thermal radiation received by space shuttles, from the plumes of the main engines. Radiation to representative surface locations were predicted using the NASA gaseous plume radiation GASRAD program. The plume model is used with the radiative view factor (RAVFAC) program to predict sea level radiation at specified body points. The GASRAD program is described along with the predictions. The RAVFAC model is also discussed.

  9. Finite element analysis of the Space Shuttle Main Engine (SSME) high pressure fuel turbopump turbine blade (HPFTP)

    NASA Technical Reports Server (NTRS)

    Lee, H. M.; Faile, G. C.; Perkins, L. B.; Yaksh, M. C.

    1989-01-01

    Cracking of the turbine blades of the SSME HPFTP is studied using two- and three-dimensional finite element analysis. The development and composition of the two- and three-dimensional models are described. Analyses are conducted under the speed, pressure, and thermal load conditions that occur during the full power level of the engine. The effects of friction on the two-dimensional model are examined. The strain and life cycle data reveal that the LCF cracking in the first stage is not probable unless the effects of fit-up tolerance between the blade and rotor are present, and for the second stage it is predicted that hydrogen assisted LCF cracking will occur under the present thermal environment. Design modifications to alleviate this cracking are discussed.

  10. National Launch System Space Transportation Main Engine

    NASA Technical Reports Server (NTRS)

    Hoodless, Ralph M., Jr.; Monk, Jan C.; Cikanek, Harry A., III

    1991-01-01

    The present liquid-oxygen/liquid-hydrogen engine is described as meeting the specific requirements of the National Launch System (NLS) Program including cost-effectiveness and robustness. An overview of the NLS and its objectives is given which indicates that the program aims to develop a flexible launch system to meet security, civil, and commercial needs. The Space Transportation Main Engine (STME) provides core and boost propulsion for the 1.5-stage vehicle and core propulsion for the solid booster vehicle. The design incorporates step-throttling, order-of-magnitude reductions in welds, and configuration targets designed to optimize robustness. The STME is designed to provide adaptable and dependable propulsion while minimizing recurring costs and is designed to meet the needs of NLS and other typical space-transportation programs currently being planned.

  11. Finite element analysis of the Space Shuttle Main Engine (SSME) alternate turbopump development (ATD) high pressure oxydizer turbopump (HPOTP)

    NASA Technical Reports Server (NTRS)

    Ham-Battista, G. L.; Helmick, G. L.; Hunt, G. L.; Franck, C. G.

    1993-01-01

    A 3D model of all stationary components of the ATD HPOTP is analyzed using a superelement solution technique to obtain a better understanding of the pump behavior and to support pump testing. Emphasis is place on the methods used for determining deflections. As part of the model verification, analyses were conducted on the main housing model under proof-pressure and push-test loading conditions. The analysis at 109 percent rate power level resulted in asymmetric deformation patterns which were used to calculate operating and rub clearances. The present analysis is considered to provide the most realistic representation of the ATD HPOTP to date.

  12. Space shuttle main engine hardware simulation

    NASA Technical Reports Server (NTRS)

    Vick, H. G.; Hampton, P. W.

    1985-01-01

    The Huntsville Simulation Laboratory (HSL) provides a simulation facility to test and verify the space shuttle main engine (SSME) avionics and software system using a maximum complement of flight type hardware. The HSL permits evaluations and analyses of the SSME avionics hardware, software, control system, and mathematical models. The laboratory has performed a wide spectrum of tests and verified operational procedures to ensure system component compatibility under all operating conditions. It is a test bed for integration of hardware/software/hydraulics. The HSL is and has been an invaluable tool in the design and development of the SSME.

  13. Improvement of Space Shuttle Main Engine Low Frequency Acceleration Measurements

    NASA Technical Reports Server (NTRS)

    Stec, Robert C.

    1999-01-01

    The noise floor of low frequency acceleration data acquired on the Space Shuttle Main Engines is higher than desirable. Difficulties of acquiring high quality acceleration data on this engine are discussed. The approach presented in this paper for reducing the acceleration noise floor focuses on a search for an accelerometer more capable of measuring low frequency accelerations. An overview is given of the current measurement system used to acquire engine vibratory data. The severity of vibration, temperature, and moisture environments are considered. Vibratory measurements from both laboratory and rocket engine tests are presented.

  14. Space Shuttle Main Engine real time stability analysis

    NASA Technical Reports Server (NTRS)

    Kuo, F. Y.

    1993-01-01

    The Space Shuttle Main Engine (SSME) is a reusable, high performance, liquid rocket engine with variable thrust. The engine control system continuously monitors the engine parameters and issues propellant valve control signals in accordance with the thrust and mixture ratio commands. A real time engine simulation lab was installed at MSFC to verify flight software and to perform engine dynamic analysis. A real time engine model was developed on the AD100 computer system. This model provides sufficient fidelity on the dynamics of major engine components and yet simplified enough to be executed in real time. The hardware-in-the-loop type simulation and analysis becomes necessary as NASA is continuously improving the SSME technology, some with significant changes in the dynamics of the engine. The many issues of interfaces between new components and the engine can be better understood and be resolved prior to the firing of the engine. In this paper, the SSME real time simulation Lab at the MSFC, the SSME real time model, SSME engine and control system stability analysis, both in real time and non-real time is presented.

  15. Studies and analyses of the space shuttle main engine: High-pressure oxidizer turbopump failure information propagation model

    NASA Technical Reports Server (NTRS)

    Glover, R. C.; Rudy, S. W.; Tischer, A. E.

    1987-01-01

    The high-pressure oxidizer turbopump (HPOTP) failure information propagation model (FIPM) is presented. The text includes a brief discussion of the FIPM methodology and the various elements which comprise a model. Specific details of the HPOTP FIPM are described. Listings of all the HPOTP data records are included as appendices.

  16. General view of a Space Shuttle Main Engine (SSME) mounted ...

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

    General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping diagonally across the top of the assembly and connecting to the High-Pressure Fuel Turbopump, the Low-Pressure Oxidizer Turbopump (LPOTP) located center right of the assembly and the LPOTP Discharge Duct looping around from the pump to the underside of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  17. Closeup view of the top of Space Shuttle Main Engine ...

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

    Close-up view of the top of Space Shuttle Main Engine (SSME) 2057 mounted in a SSME Engine Handler in the Vertical Processing area of the SSME Processing Facility at Kennedy Space Center. The most prominent components in this view is the large Low-Pressure Oxidizer Turbopump (LPOTP) Discharge Duct wrapping itself around the right side of the engine assembly. The smaller tube to the left of LPOTP Discharge Duct is the High-Pressure Oxidizer Duct used to supply the turbine of the LPOTP. The other major feature in this view is the Low-Pressure Fuel Turbopump at the top of the engine assembly. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  18. 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

  19. 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

  20. Condition monitoring helps make the Space Shuttle Main Engine reusable

    NASA Technical Reports Server (NTRS)

    Lacroix, W. P.

    1973-01-01

    The Space Shuttle Main Engine (SSME) is a reusable, high-performance liquid-propellant rocket engine being developed for the Space Shuttle Orbiter Vehicle. The SSME has been designed for long life, rapid postflight maintenance, and a fast vehicle turnaround cycle of 160 hours. To meet the unique reusability requirements, the SSME considers maintainability and condition monitoring much as airlines do today. The condition monitoring capabilities designed into this engine are discussed with major emphasis on internal inspection and techniques which ensure the reusability of the SSME.

  1. Fault diagnosis for the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Duyar, Ahmet; Merrill, Walter

    1992-01-01

    A conceptual design of a model-based fault detection and diagnosis system is developed for the Space Shuttle main engine. The design approach consists of process modeling, residual generation, and fault detection and diagnosis. The engine is modeled using a discrete time, quasilinear state-space representation. Model parameters are determined by identification. Residuals generated from the model are used by a neural network to detect and diagnose engine component faults. Fault diagnosis is accomplished by training the neural network to recognize the pattern of the respective fault signatures. Preliminary results for a failed valve, generated using a full, nonlinear simulation of the engine, are presented. These results indicate that the developed approach can be used for fault detection and diagnosis. The results also show that the developed model is an accurate and reliable predictor of the highly nonlinear and very complex engine.

  2. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 2: High pressure oxidizer turbo-pump turbine end bearing analysis

    NASA Technical Reports Server (NTRS)

    Sisk, Gregory A.

    1989-01-01

    The high-pressure oxidizer turbopump (HPOTP) consists of two centrifugal pumps, on a common shaft, that are directly driven by a hot-gas turbine. Pump shaft axial thrust is balanced in that the double-entry main inducer/impeller is inherently balanced and the thrusts of the preburner pump and turbine are nearly equal but opposite. Residual shaft thrust is controlled by a self-compensating, non-rubbing, balance piston. Shaft hang-up must be avoided if the balance piston is to perform properly. One potential cause of shaft hang-up is contact between the Phase 2 bearing support and axial spring cartridge of the HPOTP main pump housing. The status of the bearing support/axial spring cartridge interface is investigated under current loading conditions. An ANSYS version 4.3, three-dimensional, finite element model was generated on Lockheed's VAX 11/785 computer. A nonlinear thermal analysis was then executed on the Marshall Space Flight Center Engineering Analysis Data System (EADS). These thermal results were then applied along with the interference fit and bolt preloads to the model as load conditions for a static analysis to determine the gap status of the bearing support/axial spring cartridge interface. For possible further analysis of the local regions of HPOTP main pump housing assembly, detailed ANSYS submodels were generated using I-DEAS Geomod and Supertab (Appendix A).

  3. A study of boiling heat transfer as applied to the cooling of ball bearings in the high pressure oxygen turbopump of the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Schreiber, Will

    1986-01-01

    Two sets of ball bearings support the main shaft within the High Pressure Oxygen Turbopump (HPOTP) in the Space Shuttle Main Engine (SSME). In operation, these bearings are cooled and lubricated with high pressure liquid oxygen (LOX) flowing axially through the bearing assembly. Currently, modifications in the assembly design are being contemplated in order to enhance the lifetime of the bearings and to allow the HPOTP to operate under larger loads. An understanding of the fluid dynamics and heat transfer characteristics of the flowing LOX is necessary for the implementation of these design changes. The proposed computational model of the LOX fluid dynamics, in addition to dealing with a turbulent flow in a complex geometry, must address the complication associated with boiling and two-phase flow. The feasibility of and possible methods for modeling boiling heat transfer are considered. The theory of boiling as pertains to this particular problem is reviewed. Recommendations are given for experiments which would be necessary to establish validity for correlations needed to model boiling.

  4. Space Shuttle Main Engine Liquid Air Insulation Redesign Lessons Learned

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell; Carroll, Paul; Head, Kenneth; Fasheh, John; Stuart, Jessica

    2010-01-01

    The Space Shuttle Main Engine Liquid Air Insulation redesign was required to prevent the reoccurance of the STS-111 High Pressure Speed Sensor In-Flight Anomaly. The STS-111 In-Flight Anomaly Failure Investigation Team's initial redesign of the High Pressure Fuel Turbopump Pump End Ball Bearing Liquid Air Insulation failed the certification test by producing Liquid Air. The certification test failure indicated not only the High Pressure Fuel Turbopump Liquid Air Insulation, but all other Space Shuttle Main Engine Liquid Air Insulation. This paper will document the original Space Shuttle Main Engine Liquid Air STS-111 In-Flight Anomaly investigation, the heritage Space Shuttle Main Engine Insulation certification testing faults, the techniques and instrumentation used to accurately test the Liquid Air Insulation systems on the Stennis Space Center SSME test stand, the analysis techniques used to identify the Liquid Air Insulation problem areas and the analytical verification of the redesign before entering certification testing, Trade study down selected to three potential design solutions, the results of the development testing which down selected the final Liquid Air Redesign are also documented within this paper.

  5. Space Shuttle Main Engine Liquid Air Insulation Redesign Lessons Learned

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell; Carroll, Paul; Head, Kenneth; Fasheh, John; Stuart, Jessica

    2010-01-01

    The Space Shuttle Main Engine Liquid Air Insulation redesign was required to prevent the reoccurance of the STS-111 High Pressure Speed Sensor In-Flight Anomaly. The STS-111 In-Flight Anomaly Failure Investigation Team's initial redesign of the High Pressure Fuel Turbopump Pump End Ball Bearing Liquid Air Insulation failed the certification test by producing Liquid Air. The certification test failure indicated not only the High Pressure Fuel Turbopump Liquid Air Insulation, but all other Space Shuttle Main Engine Liquid Air Insulation. This paper will document the original Space Shuttle Main Engine Liquid Air STS-111 In-Flight Anomaly investigation, the heritage Space Shuttle Main Engine Insulation certification testing faults, the techniques and instrumentation used to accurately test the Liquid Air Insulation systems on the Stennis Space Center SSME test stand, the analysis techniques used to identify the Liquid Air Insulation problem areas and the analytical verification of the redesign before entering certification testing, Trade study down selected to three potential design solutions, the results of the development testing which down selected the final Liquid Air Redesign are also documented within this paper.

  6. The simulation of the alternate turbopump development high pressure oxygen and fuel turbopumps for the space shuttle main engine using the Shaberth computer program

    NASA Technical Reports Server (NTRS)

    Mcdonald, Gary H.

    1988-01-01

    The Space Shuttle Main Engine (SSME) is basically comprised of a combustion chamber and nozzle, high and low pressure oxygen turbopumps and high and low pressure fuel turbopumps. In the current configuration, the high pressure fuel (HPTFP) and high pressure oxygen turbopumps (HPOTP) have experienced a history of ball bearing wear. The wear problem can be attributed to numerous factors including the hydrodynamic axial and radial loads caused by the flow of liquid oxygen and liquid hydrogen through the turbopump impellers and turbine. Also, friction effects between the rolling elements, races, and cage can create thermally induced bearing geometry changes. To alleviate some of the current configuration problems, an alternate turbopump development (ATD) was proposed. However, the ATD HPOTP and HPTFP are constrained to operate interchangeably with the current turbopumps, thus, the operation conditions must be similar. The ATD configuration features a major change in bearings used to support the integrated shaft, impeller, and turbine system. A single ball and single roller will replace the pump-end and turbine and duplex ball bearings. The Shaft-Bearing-Thermal (SHABERTH) computer code was used to model the ATD HPOTP and ATD HPFTP configurations. A two bearing model was used to simulate the HPOTP and HPFTP bearings and shaft geometry. From SHABERTH, a comparison of bearing reaction loads, frictional heat generation rates, and Hertz contact stresses will be attempted with analysis at the 109 percent and 65 percent power levels.

  7. Developmental problems and their solution for the Space Shuttle main engine alternate liquid oxygen high-pressure turbopump: Anomaly or failure investigation the key

    NASA Technical Reports Server (NTRS)

    Ryan, R.; Gross, L. A.

    1995-01-01

    The Space Shuttle main engine (SSME) alternate high-pressure liquid oxygen pump experienced synchronous vibration and ball bearing life problems that were program threatening. The success of the program hinged on the ability to solve these development problems. The design and solutions to these problems are engirded in the lessons learned and experiences from prior programs, technology programs, and the ability to properly conduct failure or anomaly investigations. The failure investigation determines the problem cause and is the basis for recommending design solutions. For a complex problem, a comprehensive solution requires that formal investigation procedures be used, including fault trees, resolution logic, and action items worked through a concurrent engineering-multidiscipline team. The normal tendency to use an intuitive, cut-and-try approach will usually prove to be costly, both in money and time and will reach a less than optimum, poorly understood answer. The SSME alternate high-pressure oxidizer turbopump development has had two complex problems critical to program success: (1) high synchronous vibrations and (2) excessive ball bearing wear. This paper will use these two problems as examples of this formal failure investigation approach. The results of the team's investigation provides insight into the complexity of the turbomachinery technical discipline interacting/sensitivities and the fine balance of competing investigations required to solve problems and guarantee program success. It is very important to the solution process that maximum use be made of the resources that both the contractor and Government can bring to the problem in a supporting and noncompeting way. There is no place for the not-invented-here attitude. The resources include, but are not limited to: (1) specially skilled professionals; (2) supporting technologies; (3) computational codes and capabilities; and (4) test and manufacturing facilities.

  8. Fatigue Failure of Space Shuttle Main Engine Turbine Blades

    NASA Technical Reports Server (NTRS)

    Swanson, Gregrory R.; Arakere, Nagaraj K.

    2000-01-01

    Experimental validation of finite element modeling of single crystal turbine blades is presented. Experimental results from uniaxial high cycle fatigue (HCF) test specimens and full scale Space Shuttle Main Engine test firings with the High Pressure Fuel Turbopump Alternate Turbopump (HPFTP/AT) provide the data used for the validation. The conclusions show the significant contribution of the crystal orientation within the blade on the resulting life of the component, that the analysis can predict this variation, and that experimental testing demonstrates it.

  9. General view of the Space Shuttle Main Engine (SSME) assembly ...

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

    General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-pressure oxidizer Turbopump discharge Duct looping from the upper left side of the engine assembly to the lower left side of the assembly, the Low-Pressure Fuel Turbopump (LPFTP) is on the upper left of the assembly in this view and the LPFTP Discharge Duct loops from the upper left to upper right then turns back and down the assembly to the High-Pressure Fuel Turbopump on the lower right of the assembly. The Engine Controller and the Main fuel Valve Hydraulic Actuator are on the lower left portion of the assembly. The vertical rod that is in the approximate center of the engine assembly is a piece of ground support equipment call a Gimbal Actuator Replacement Strut which are used on the SSMEs when they are not installed in an orbiter. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  10. Model Verification and Validation Concepts for a Probabilistic Fracture Assessment Model to Predict Cracking of Knife Edge Seals in the Space Shuttle Main Engine High Pressure Oxidizer

    NASA Technical Reports Server (NTRS)

    Pai, Shantaram S.; Riha, David S.

    2013-01-01

    Physics-based models are routinely used to predict the performance of engineered systems to make decisions such as when to retire system components, how to extend the life of an aging system, or if a new design will be safe or available. Model verification and validation (V&V) is a process to establish credibility in model predictions. Ideally, carefully controlled validation experiments will be designed and performed to validate models or submodels. In reality, time and cost constraints limit experiments and even model development. This paper describes elements of model V&V during the development and application of a probabilistic fracture assessment model to predict cracking in space shuttle main engine high-pressure oxidizer turbopump knife-edge seals. The objective of this effort was to assess the probability of initiating and growing a crack to a specified failure length in specific flight units for different usage and inspection scenarios. The probabilistic fracture assessment model developed in this investigation combined a series of submodels describing the usage, temperature history, flutter tendencies, tooth stresses and numbers of cycles, fatigue cracking, nondestructive inspection, and finally the probability of failure. The analysis accounted for unit-to-unit variations in temperature, flutter limit state, flutter stress magnitude, and fatigue life properties. The investigation focused on the calculation of relative risk rather than absolute risk between the usage scenarios. Verification predictions were first performed for three units with known usage and cracking histories to establish credibility in the model predictions. Then, numerous predictions were performed for an assortment of operating units that had flown recently or that were projected for future flights. Calculations were performed using two NASA-developed software tools: NESSUS(Registered Trademark) for the probabilistic analysis, and NASGRO(Registered Trademark) for the fracture

  11. Space Shuttle Main Engine - The Relentless Pursuit of Improvement

    NASA Technical Reports Server (NTRS)

    VanHooser, Katherine P.; Bradley, Douglas P.

    2011-01-01

    The Space Shuttle Main Engine (SSME) is the only reusable large liquid rocket engine ever developed. The specific impulse delivered by the staged combustion cycle, substantially higher than previous rocket engines, minimized volume and weight for the integrated vehicle. The dual pre-burner configuration permitted precise mixture ratio and thrust control while the fully redundant controller and avionics provided a very high degree of system reliability and health diagnosis. The main engine controller design was the first rocket engine application to incorporate digital processing. The engine was required to operate at a high chamber pressure to minimize engine volume and weight. Power level throttling was required to minimize structural loads on the vehicle early in flight and acceleration levels on the crew late in ascent. Fatigue capability, strength, ease of assembly and disassembly, inspectability, and materials compatibility were all major considerations in achieving a fully reusable design. During the multi-decade program the design evolved substantially using a series of block upgrades. A number of materials and manufacturing challenges were encountered throughout SSME s history. Significant development was required for the final configuration of the high pressure turbopumps. Fracture control was implemented to assess life limits of critical materials and components. Survival in the hydrogen environment required assessment of hydrogen embrittlement. Instrumentation systems were a challenge due to the harsh thermal and dynamic environments within the engine. Extensive inspection procedures were developed to assess the engine components between flights. The Space Shuttle Main Engine achieved a remarkable flight performance record. All flights were successful with only one mission requiring an ascent abort condition, which still resulted in an acceptable orbit and mission. This was achieved in large part via extensive ground testing to fully characterize

  12. Turbopump configuration selection for the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Rothe, K.

    1974-01-01

    Studies to define the optimum turbopump configurations for the Space Shuttle propulsion system are reported. For each propellant, two turbopumps - one low-pressure and one high-pressure - are needed to generate the high discharge pressures required for engine operation. The optimization of the four pumps resulted in the selection of an axial inducer type for both low-pressure pumps and in a three-stage centrifugal pump for the high-pressure hydrogen turbopump; meanwhile the oxygen pump features a double inlet main impeller. This impeller feeds the thrust chamber injector, as well as a preburner pump, which boosts the main impeller discharge pressure to the required preburner pressure. The interaction between engine performance and obtainable turbopump performance is discussed, and the reasons for the final selection of the turbine and pump types are presented.

  13. High-frequency data observations from space shuttle main engine low pressure fuel turbopump discharge duct flex joint tripod failure investigation

    NASA Technical Reports Server (NTRS)

    Zoladz, T. F.; Farr, R. A.

    1991-01-01

    Observations made by Marshall Space Flight Center (MSFC) engineers during their participation in the Space Shuttle Main Engine (SSME) low pressure fuel turbopump discharge duct flex joint tripod failure investigation are summarized. New signal processing techniques used by the Component Assessment Branch and the Induced Environments Branch during the failure investigation are described in detail. Moreover, nonlinear correlations between frequently encountered anomalous frequencies found in SSME dynamic data are discussed. A recommendation is made to continue low pressure fuel (LPF) duct testing through laboratory flow simulations and MSFC-managed technology test bed SSME testing.

  14. Space Shuttle Main Engine turbopump bearing assessment program

    NASA Technical Reports Server (NTRS)

    Breithaupt, Barbara Spiegel

    1994-01-01

    This paper documents the work done on the bearing assessment program over the past two and a half years. The objective of the program is to develop a nondestructive evaluation system for the space shuttle main engine high pressure oxidizer turbopumps which would be used to detect anomalies in installed bearings without component disassembly. Databases of various signatures are obtained by slowly turning the pump shafts before and after an engine firing. These signatures are then analyzed and compared to the original signatures to more accurately predict bearing wear.

  15. 28. Main engine air pump located to port side of ...

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

    28. Main engine air pump located to port side of main engine cylinder beside engine bed. Dynamo lies aft of air pump (at right), pipe at extreme left of image carries lake water to condenser valves. - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT

  16. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 7: High pressure fuel turbo-pump third stage impeller analysis

    NASA Technical Reports Server (NTRS)

    Pool, Kirby V.

    1989-01-01

    This volume summarizes the analysis used to assess the structural life of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbo-Pump (HPFTP) Third Stage Impeller. This analysis was performed in three phases, all using the DIAL finite element code. The first phase was a static stress analysis to determine the mean (non-varying) stress and static margin of safety for the part. The loads involved were steady state pressure and centrifugal force due to spinning. The second phase of the analysis was a modal survey to determine the vibrational modes and natural frequencies of the impeller. The third phase was a dynamic response analysis to determine the alternating component of the stress due to time varying pressure impulses at the outlet (diffuser) side of the impeller. The results of the three phases of the analysis show that the Third Stage Impeller operates very near the upper limits of its capability at full power level (FPL) loading. The static loading alone creates stresses in some areas of the shroud which exceed the yield point of the material. Additional cyclic loading due to the dynamic force could lead to a significant reduction in the life of this part. The cyclic stresses determined in the dynamic response phase of this study are based on an assumption regarding the magnitude of the forcing function.

  17. Thermographic Leak Detection of the Space Shuttle Main Engine Nozzle

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Russell, Samuel S.

    1999-01-01

    The Space Shuttle Main Engines Nozzles consist of over one thousand tapered Inconel coolant tubes brazed to a stainless steel structural jacket. Liquid Hydrogen flows through the tubing, from the aft to forward end of the nozzle, under high pressure to maintain a thermal balance between the rocket exhaust and the nozzle wall. Three potential problems occur within the SSME nozzle coolant tubes as a result of manufacturing anomalies and the highly volatile service environment including poor or incomplete bonding of the tubes to the structural jacket, cold wall leaks and hot wall leaks. Of these conditions the identification of cold wall leaks has been the most problematic. The methods and results presented in this summary addresses the thermographic identification of cold wall "interstitial" leaks between the structural jacket and coolant tubes of the Space Shuttle Main Engines Nozzles.

  18. 5. ENGINE TEST CELL BUILDING INTERIOR. CENTRAL ROOM ON MAIN ...

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

    5. ENGINE TEST CELL BUILDING INTERIOR. CENTRAL ROOM ON MAIN FLOOR. LOOKING NORTHWEST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  19. Electrodeposition applications for the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Otousa, J. E.

    1979-01-01

    Electrodeposition processes play a key role in the fabrication and in-service performance of the Space Shuttle Main Engine. Applications range from the electroforming of the main combustion chamber to the deposition of high-purity copper or gold for hydrogen embrittlement protection of susceptible materials of construction, or nickel for mechanical protection of foam insulated propellant ducts. Techniques for controlling electrolyte purity, verification of deposit integrity, and deposit profile and thickness are reported. The use of in-situ techniques (cell-plating) for localized plating and repair of damaged substrate materials are summarized.

  20. Electrodeposition applications for the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Otousa, J. E.

    1979-01-01

    Electrodeposition processes play a key role in the fabrication and in-service performance of the Space Shuttle Main Engine. Applications range from the electroforming of the main combustion chamber to the deposition of high-purity copper or gold for hydrogen embrittlement protection of susceptible materials of construction, or nickel for mechanical protection of foam insulated propellant ducts. Techniques for controlling electrolyte purity, verification of deposit integrity, and deposit profile and thickness are reported. The use of in-situ techniques (cell-plating) for localized plating and repair of damaged substrate materials are summarized.

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

    NASA Technical Reports Server (NTRS)

    Davidson, Matt; Stephens, John; Rodela, Chris

    2006-01-01

    Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

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

    NASA Technical Reports Server (NTRS)

    Davidson, Matt; Stephens, John; Rodela, Chris

    2006-01-01

    Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

  3. The STS-93 crew look over orbiter Columbia's main engine

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the Space Shuttle Main Engine Facility, , STS-93 crew members listen to Site Director Dan Hausman, with Rocketdyne, while looking over the main engine of the Space Shuttle Columbia. From left, they are Pilot Jeffrey S. Ashby, Mission Specialists Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), and Mission Specialist Catherine G. Coleman, Commander Eileen Collins and Mission Specialist Steven A. Hawley. STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

  4. The STS-93 crew look over orbiter Columbia's main engine

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the Space Shuttle Main Engine Facility, the STS-93 crew poses in the nozzle of Space Shuttle Columbia's main engine. From left, they are Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), Commander Eileen Collins, Mission Specialist Catherine G. Coleman, Pilot Jeffrey S. Ashby, and Mission Specialist Steven A. Hawley. STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

  5. 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.

  6. Unique material requirements in the Space Shuttle Main Engines

    NASA Technical Reports Server (NTRS)

    Fulton, D. L.; Shoemaker, M. C.; Bashir, S.

    1983-01-01

    Components operating in staged-combustion cycle liquid fuel rocket engines such as the Space Shuttle Main Engines (SSMEs) are subjected to severe temperature changes during start/stop transients, together with extremely high pressures, corrosive gases, high fluid velocities, demanding weight-control criteria, etc. Attention is given to the selection and application of metallic and nonmetallic materials for high temperature resistance, cryogenic properties, and hydrogen and oxygen compatibility. The materials in question include polyimides, Kel-F, Armalon, and Teflon among plastics, and gold and copper platings, weld-overlays and heat treatment modifications among metals and metallic processing techniques. The polymeric materials are oxygen-resistant, and the metallic ones hydrogen-resistant.

  7. Unique material requirements in the Space Shuttle Main Engines

    NASA Technical Reports Server (NTRS)

    Fulton, D. L.; Shoemaker, M. C.; Bashir, S.

    1983-01-01

    Components operating in staged-combustion cycle liquid fuel rocket engines such as the Space Shuttle Main Engines (SSMEs) are subjected to severe temperature changes during start/stop transients, together with extremely high pressures, corrosive gases, high fluid velocities, demanding weight-control criteria, etc. Attention is given to the selection and application of metallic and nonmetallic materials for high temperature resistance, cryogenic properties, and hydrogen and oxygen compatibility. The materials in question include polyimides, Kel-F, Armalon, and Teflon among plastics, and gold and copper platings, weld-overlays and heat treatment modifications among metals and metallic processing techniques. The polymeric materials are oxygen-resistant, and the metallic ones hydrogen-resistant.

  8. 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.

  9. General view of the Space Shuttle Main Engine (SSME) assembly ...

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

    General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-pressure Fuel Turbopump discharge Duct looping from the upper left side of the engine assembly to the lower left side of the assembly, the Low-Pressure Oxidizer Turbopump (LPOTP) is on the upper left of the assembly in this view and the LPOTP Discharge Duct loops from the upper left to upper right. The sphere in the middle right side of the assembly in this view is the POGO System Accumulator , the partial sphere to its left and slightly more toward the center of the assembly is the Heat Exchanger on the Oxidizer Preburner side of the Hot Gas Manifold, beneath that is the High-Pressure Oxidizer Turbopump (HPOTP) and the HPOTP Discharge duct loops from the pump around to the lower left of the assembly. The Pneumatic Control Assembly is in the approximate center of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  10. Lubrication of Space Shuttle Main Engine Turbopump Bearings

    NASA Technical Reports Server (NTRS)

    Gibson, Howard; Munafo, Paul (Technical Monitor)

    2001-01-01

    The Space Shuttle has three main engines that are used for propulsion into orbit. These engines are fed propellants by four turbopumps on each engine. A main element in the turbopump is the bearings supporting the rotor that spins the turbine blades and the pump impeller. These bearings are required to spin at very high speeds, support radial and thrust loads, and have high wear resistance without the benefit of lubrication. The liquid hydrogen and oxygen propellants flow through the bearings to cool the surfaces. The volatile nature of the propellants excludes any conventional means of lubrication. Lubrication for these bearings is provided by the ball separator inside the bearing. The separator is a composite material that supplies a transfer film of lubrication to the rings and balls. New separator materials and lubrication schemes have been investigated at Marshall Space Flight Center in a bearing test rig with promising results. Hybrid bearings with silicon nitride balls have also been evaluated. The use of hybrid, silicon nitride ball bearings in conjunction -with better separator materials has shown excellent results. The work that Marshall has done is being utilized in turbopumps flying on the space shuttle fleet and will be utilized in future space travel. This result of this work is valuable for all aerospace and commercial applications where high-speed bearings are used.

  11. Lubrication of Space Shuttle Main Engine Turbopump Bearings

    NASA Technical Reports Server (NTRS)

    Gibson, Howard; Munafo, Paul (Technical Monitor)

    2001-01-01

    The Space Shuttle has three main engines that are used for propulsion into orbit. These engines are fed propellants by four turbopumps on each engine. A main element in the turbopump is the bearings supporting the rotor that spins the turbine blades and the pump impeller. These bearings are required to spin at very high speeds, support radial and thrust loads, and have high wear resistance without the benefit of lubrication. The liquid hydrogen and oxygen propellants flow through the bearings to cool the surfaces. The volatile nature of the propellants excludes any conventional means of lubrication. Lubrication for these bearings is provided by the ball separator inside the bearing. The separator is a composite material that supplies a transfer film of lubrication to the rings and balls. New separator materials and lubrication schemes have been investigated at Marshall Space Flight Center in a bearing test rig with promising results. Hybrid bearings with silicon nitride balls have also been evaluated. The use of hybrid, silicon nitride ball bearings in conjunction -with better separator materials has shown excellent results. The work that Marshall has done is being utilized in turbopumps flying on the space shuttle fleet and will be utilized in future space travel. This result of this work is valuable for all aerospace and commercial applications where high-speed bearings are used.

  12. Space Shuttle Main Engine (SSME) Reliability and Analysis Evolution

    NASA Technical Reports Server (NTRS)

    Stephens, Walter E.; Rogers, James H.; Biggs, Robert E.

    2010-01-01

    The Space Shuttle Main Engine (SSME) is a large thrust class, reusable, staged combustion cycle rocket engine employing liquid hydrogen and liquid oxygen propellants. A cluster of three SSMEs is used on every space shuttle mission to propel the space shuttle orbiter vehicle into low earth orbit. Development of the SSME began in the early 70 s and the first flight of the space shuttle occurred in 1981. Today, the SSME has accrued over one million seconds of ground test and flight operational time, launching 129 space shuttle missions. Given that the SSME is used to launch a manned vehicle, its reliability must be commensurate for the task. At the same time, the SSME is a high performance, high power density engine which traditionally does not lend itself towards high reliability. Furthermore, throughout its history, the SSME operational envelope has been explored and expanded leading to several major test failures. Hence, assessing the reliability of the SSME throughout its history has been a challenging undertaking. This paper provides a review and discussion of SSME reliability assessment techniques and results over its history. Basic reliability drivers such as engine design, test program, major failures, redesigns and upgrades will also be discussed.

  13. Presenting the Shuttle Main Engine Software

    NASA Technical Reports Server (NTRS)

    Schreur, Barbara

    1998-01-01

    Originally, this project was to produce an animated Powerpoint presentation of the 'Shuttle Engine and its Software' and to produce a web page with animation including the same materials but with greater detail in the description of the software. The principal emphasis was to be on the web page. Midway through the first year of the project, we were advised by the technical coordinator of this work at MSFC to concentrate on the web page alone. Also, the project was expanded to include a web presentation of the MRECS (Modular Rocket Control System). For the SSME project, the web page presentation has been completed. The integration of the animation into the web page is complete although we have been asked to speed up the animation. Also, the addition of greater detail to the description of the SSME controller software has been added. Much of the work on this program was done by students as their task for their senior project course, the capstone course of their program of study. The students gained a great deal from this project. They have learned to use VISIO, POWERPOINT, PHOTOSHOP, and several web page software packages. The starting point for this project was a PowerPoint presentation by the PI while on a Summer Faculty Fellowship at MSFC. For this project, about half of the drawings of the SSME were improved and about half were completely redrawn. The original still drawings have been animated to illustrate the fuel flow through the SSME system.

  14. Presenting the Shuttle Main Engine Software

    NASA Technical Reports Server (NTRS)

    Schreur, Barbara

    1998-01-01

    Originally, this project was to produce an animated Powerpoint presentation of the 'Shuttle Engine and its Software' and to produce a web page with animation including the same materials but with greater detail in the description of the software. The principal emphasis was to be on the web page. Midway through the first year of the project, we were advised by the technical coordinator of this work at MSFC to concentrate on the web page alone. Also, the project was expanded to include a web presentation of the MRECS (Modular Rocket Control System). For the SSME project, the web page presentation has been completed. The integration of the animation into the web page is complete although we have been asked to speed up the animation. Also, the addition of greater detail to the description of the SSME controller software has been added. Much of the work on this program was done by students as their task for their senior project course, the capstone course of their program of study. The students gained a great deal from this project. They have learned to use VISIO, POWERPOINT, PHOTOSHOP, and several web page software packages. The starting point for this project was a PowerPoint presentation by the PI while on a Summer Faculty Fellowship at MSFC. For this project, about half of the drawings of the SSME were improved and about half were completely redrawn. The original still drawings have been animated to illustrate the fuel flow through the SSME system.

  15. Main Chamber Injectors for Advanced Hydrocarbon Booster Engines

    NASA Technical Reports Server (NTRS)

    Long, Matthew R.; Bazarov, Vladimir G.; Anderson, William E.

    2003-01-01

    Achieving the highest possible specific impulse has long been a key driver for space launch systems. Recently, more importance has been placed on the need for increased reliability and streamlined launch operations. These general factors along with more specific mission requirements have provided a new focus that is centered on the oxidizer rich staged combustion (ORSC) cycle. Despite a history of use in Russia that extends back to the 1960's, a proven design methodology for ORSC cycle engines does not exist in the West. This lack of design expertise extends to the main chamber injector, a critical subcomponent that largely determines the engine performance and main chamber life. The goals of the effort described here are to establish an empirical knowledge base to provide a fundamental understanding of main chamber injectors and for verification of an injector design methodology for the ORSC cycle. The design of a baseline injector element, derived from information on Russian engines in the open literature, is presented. The baseline injector comprises a gaseous oxidizer core flow and an annular swirling fuel flow. Sets of equations describing the steady-state and the dynamic characteristics of the injector are presented; these equations, which form the basis of the design analysis methodology, will be verified in tests later this year. On-going cold flow studies, using nitrogen and water as simulants, are described which indicate highly atomized and symmetric sprays.

  16. Finite element models of the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Muller, G. R.

    1980-01-01

    Finite element models were developed as input to dynamic simulations of the high pressure fuel turbopump (HPFTP), the high pressure oxidizer turbopump (HPOTP), and the space shuttle main engine (SSME). Descriptions are provided for the five basic finite element models: HPFTP rotor, HPFTP case, HPOTP rotor, HPOTP case, and SSME (excluding turbopumps). Modal results are presented for the HPFTP rotor, HPFTP case, HPOTP rotor, coupled HPFTP rotor and case, HPOTP case, coupled HPOTP rotor and case, SSME (excluding turbopumps), and SSME (including turbopumps). Results for the SSME (including turbopumps) model are compared to data from a SSME HPOTP modal survey.

  17. Space shuttle three main engine return to launch site abort

    NASA Technical Reports Server (NTRS)

    Carter, J. F.; Bown, R. L.

    1975-01-01

    A Return-to-Launch-Site (RTLS) abort with three Space Shuttle Main Engines (SSME) operational was examined. The results are trajectories and main engine cutoff conditions that are approximately the same as for a two SSME case. Requiring the three SSME solution to match the two SSME abort eliminates additional crew training and is accomplished with negligible software impact.

  18. The space transportation main engine phase A' study

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Space Transportation Main Engine Phase A prime study was conducted over a 7 month period as an extension to the Phase A study. The Phase A prime program was designed to expand the study effort completed in Phase A, focusing on the baseline engine configuration selected. Analysis and trade studies were conducted to further optimize some of the major engine subsystems. These changes resulted in improvements to the baseline engine. Several options were evaluated for consideration by vehicle contractors.

  19. Stability testing of a modified Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Dennis, H.; Hutt, J.; Nesman, T.

    1991-01-01

    The testing of the combustion stability characteristics of Space Shuttle Main Engine (SSME) 0208 is described in terms of augmenting the technology base for large O/H thrust-chamber assemblies. The throat area is increased by 12 percent over that of the flight SSMEs, and the thrust chamber assembly does not include stability aids. Acoustic modes in the chamber are excited by means of rapid pressure generators employed in the start-transient through mainstage operations. Stability characteristics are determined by damp times which are facilitated by high-frequency instrumentation measuring oscillations and locating stable operating regions. All vibration modes are damped to within the requirements for a chamber mode set forth by the Chemical Propulsion Information Agency. No sustained chamber acoustic oscillations are exhibited in engine 0208's combustion chamber configuration in spite of the absence of baffles and acoustic cavities.

  20. Duct flow nonuniformities study for space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Thoenes, J.

    1985-01-01

    To improve the Space Shuttle Main Engine (SSME) design and for future use in the development of generation rocket engines, a combined experimental/analytical study was undertaken with the goals of first, establishing an experimental data base for the flow conditions in the SSME high pressure fuel turbopump (HPFTP) hot gas manifold (HGM) and, second, setting up a computer model of the SSME HGM flow field. Using the test data to verify the computer model it should be possible in the future to computationally scan contemplated advanced design configurations and limit costly testing to the most promising design. The effort of establishing and using the computer model is detailed. The comparison of computational results and experimental data observed clearly demonstrate that computational fluid mechanics (CFD) techniques can be used successfully to predict the gross features of three dimensional fluid flow through configurations as intricate as the SSME turbopump hot gas manifold.

  1. LOX/Methane Main Engine Igniter Tests and Modeling

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin J.; Ajmani, Kumund

    2008-01-01

    The LOX/methane propellant combination is being considered for the Lunar Surface Access Module ascent main engine propulsion system. The proposed switch from the hypergolic propellants used in the Apollo lunar ascent engine to LOX/methane propellants requires the development of igniters capable of highly reliable performance in a lunar surface environment. An ignition test program was conducted that used an in-house designed LOX/methane spark torch igniter. The testing occurred in Cell 21 of the Research Combustion Laboratory to utilize its altitude capability to simulate a space vacuum environment. Approximately 750 ignition test were performed to evaluate the effects of methane purity, igniter body temperature, spark energy level and frequency, mixture ratio, flowrate, and igniter geometry on the ability to obtain successful ignitions. Ignitions were obtained down to an igniter body temperature of approximately 260 R with a 10 torr back-pressure. The data obtained is also being used to anchor a CFD based igniter model.

  2. Closeup view of a Space Shuttle Main Engine (SSME) installed ...

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

    Close-up view of a Space Shuttle Main Engine (SSME) installed in position number one on the Orbiter Discovery. A ground-support mobile platform is in place below the engine to assist in technicians with the installation of the engine. This Photograph was taken in the Orbiter Processing Facility at the Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  3. 42. William E. Barrett, Photographer, August 1975. MAIN DRIVE ENGINE ...

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

    42. William E. Barrett, Photographer, August 1975. MAIN DRIVE ENGINE FOR SAWMILL; A FILER AND STOWELL, TYPE '1900,' HEAVY DUTY CORLISS ENGINE (ser. no. 4352). NOTE EXPOSED CROSSHEAD JOINING PISTON ROD AND CONNECTING ROD. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

  4. Thousands gather to watch a Space Shuttle Main Engine Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Approximately 13,000 people fill the grounds at NASA's John C. Stennis Space Center for the first-ever evening public engine test of a Space Shuttle Main Engine. The test marked Stennis Space Center's 20th anniversary celebration of the first Space Shuttle mission.

  5. Space Shuttle Main Engine: Thirty Years of Innovation

    NASA Technical Reports Server (NTRS)

    Jue, F. H.; Hopson, George (Technical Monitor)

    2002-01-01

    The Space Shuttle Main Engine (SSME) is the first reusable, liquid booster engine designed for human space flight. This paper chronicles the 30-year history and achievements of the SSME from authority to proceed up to the latest flight configuration - the Block 2 SSME.

  6. 35. VIEW OF MAIN DECK ENGINE FLAT, LOOKING AFT AT ...

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

    35. VIEW OF MAIN DECK ENGINE FLAT, LOOKING AFT AT STEAM CHEST AND CYLINDER HEADS. ORIGINAL STEAM FIRE PUMP IS ON PORT SIDE - Steam Schooner WAPAMA, Kaiser Shipyard No. 3 (Shoal Point), Richmond, Contra Costa County, CA

  7. 18. VIEW TOWARD MAIN ENTRANCE OF AMERICAN TOOL ENGINE LATHE, ...

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

    18. VIEW TOWARD MAIN ENTRANCE OF AMERICAN TOOL ENGINE LATHE, JIB CRANE ABOVE-LOOKING NORTH. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

  8. 12. VIEW FROM MAIN ENTRANCE OF STOVE, ENGINE LATHE, AND ...

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

    12. VIEW FROM MAIN ENTRANCE OF STOVE, ENGINE LATHE, AND GRINDER (L TO R) IN FOREGROUND, SHAFTING ABOVE LOOKING SOUTH. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

  9. 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.

  10. 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.

  11. The STS-93 crew look over orbiter Columbia's main engine

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Members of the STS-93 crew look over the Space Shuttle Columbia's main engine in the Space Shuttle Main Engine Facility as they listen to Al Strainer, with United Space Alliance. From left, the crew members are Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), Pilot Jeffrey S. Ashby, Mission Specialist Steven A. Hawley, and Commander Eileen Collins. At the far right is Matt Gaetjens, with the Vehicle Integration Test Team. The fifth crew member (not shown) is Mission Specialist Catherine G. Coleman. STS-93, scheduled to launch July 9, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

  12. The STS-93 crew look over orbiter Columbia's main engine

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the Space Shuttle Main Engine Facility, STS-93 crew members listen to Site Director Dan Hausman, with Rocketdyne, while looking over the main engine of the Space Shuttle Columbia. From left, they are Mission Specialist Steven A. Hawley, Commander Eileen Collins and Pilot Jeffrey S. Ashby. Other crew members (not shown) are Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), and Mission Specialist Catherine G. Coleman. STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

  13. Space Shuttle Main Engine Turbopump Bearing Testing at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Gibson, Howard; Thom, Robert; Moore, Chip

    2010-01-01

    The Space Shuttle has three main engines that are used for lift off into orbit. These engines are fed propellants by low and high pressure turbopumps on each engine. A main element of the pumps are the bearings supporting the main shaft that spins the turbine and pumps. These bearings must spin at high speeds, support the radial and axial thrust loads, and have high wear resistance without the benefit of lubrication. This paper describes the bearing testing that was done at the Marshall Space Flight Center and the results that were obtained to provide the best bearing design possible for safe and reliable engine performance.

  14. 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.

  15. Space Shuttle Main Engine (SSME) Options for the Future Shuttle

    NASA Technical Reports Server (NTRS)

    Jue, Fred; Kuck, Fritz; McCool, Alex (Technical Monitor)

    2002-01-01

    The main engines for the Future Shuttle will focus on improved safety and operability. Performance enhancements may also be required for vehicle safety purposes to achieve more desirable abort scenarios. This paper discusses the potential improvements that will be considered for implementation into the Future Shuttle. Integrated engine and vehicle health management systems will achieve additional system-level reliability improvements over those currently in development. Advanced instrumentation for detecting leaks, analyzing component wear and degradation, and providing sophisticated operational data will be used for reliable engine control and scheduling maintenance operations. A new nozzle and main combustion chamber (MCC) will reduce failure probability by 50% and allow for higher thrust capability without requiring the entire engine to be redesigned. Turbopump improvements may range from minor component improvements to using 3rd-generation pumps built on the advanced concepts demonstrated by the Integrated Powerhead Development (IPD) program and the Space Launch Initiative (SLI) prototype engines.The main engines for the Future Shuttle will focus on improved safety and operability. Performance enhancements may also be required for vehicle safety purposes to achieve more desirable abort scenarios. This paper discusses the potential improvements that will be considered for implementation into the Future Shuttle. Integrated engine and vehicle health management systems will achieve additional system-level reliability improvements over those currently in development. Advanced instrumentation for detecting leaks, analyzing component wear and degradation, and providing sophisticated operational data will be used for reliable engine control and scheduling maintenance operations. A new nozzle and main combustion chamber (MCC) will reduce failure probability by 50% and allow for higher thrust capability without requiring the entire engine to be redesigned. Turbopump

  16. 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.

  17. Thermographic Nondestructive Evaluation of the Space Shuttle Main Engine Nozzle

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Lansing, Matthew D.; Russell, Samuel S.; Caraccioli, Paul; Whitaker, Ann F. (Technical Monitor)

    2000-01-01

    The methods and results presented in this summary address the thermographic identification of interstitial leaks in the Space Shuttle Main Engine nozzles. A highly sensitive digital infrared camera is used to record the minute cooling effects associated with a leak source, such as a crack or pinhole, hidden within the nozzle wall by observing the inner "hot wall" surface as the nozzle is pressurized. These images are enhanced by digitally subtracting a thermal reference image taken before pressurization, greatly diminishing background noise. The method provides a nonintrusive way of localizing the tube that is leaking and the exact leak source position to within a very small axial distance. Many of the factors that influence the inspectability of the nozzle are addressed; including pressure rate, peak pressure, gas type, ambient temperature and surface preparation.

  18. Space Shuttle main engine nozzle-steerhorn dynamics

    NASA Technical Reports Server (NTRS)

    Kiefling, L.

    1981-01-01

    On two occasions during the Space Shuttle main engine development, the LH2 feedline (called the steerhorn, because of its shape) failed during the cutoff transient. A dynamic test was undertaken, and an analytical model was developed and correlated to the dynamic test. Detailed models of the tube bundle were required to obtain the equivalent shell coefficients. All-shell models of the nozzle wall were found better than beam-shell models. The most difficult part of the structure to simulate was the felt-metal pad between the feedline and its mount, which introduced nonlinear stiffness and damping and led to the use of separate low amplitude and high amplitude models. The total structure was found to have 400 modes in the frequency range of interest, 0 to 500 Hz. Good test analysis correlation was obtained and a modified feedline configuration was found to demonstrate a 40% reduction of response stress from the original configuration.

  19. Design of a prototype Advanced Main Combustion Chamber for the Space Shuttle Main Engine

    NASA Astrophysics Data System (ADS)

    Lackey, J. D.; Myers, W. N.

    1992-07-01

    Development of a prototype advanced main combustion chamber is underway at NASA Marshall Space Flight Center. The Advanced Main Combustion Chamber (AMCC) project is being approached utilizing a 'concurrent engineering' concept where groups from materials, manufacturing, stress, quality, and design are involved from the initiation of the project. The AMCC design has been tailored to be compatible with the investment casting process. Jacket, inlet/outlet manifolds, inlet/outlet neck coolant flow splitters, support ribs, actuator lugs, and engine controller mounting bracket will all be a part of the one-piece AMCC casting. Casting of the AMCC in a one-piece configuration necessitated a method of forming a liner in its structural jacket. A method of vacuum plasma spraying the liner is being developed. In 1994, the AMCC will be hot-fired on the Technology Test Bed Space Shuttle Main Engine.

  20. General view of the Space Shuttle Main Engine (SSME) assembly ...

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

    General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-Pressure Fuel Turbopump (LPFTP) on the upper left of the engine assembly, the LPFTP Discharge Duct looping around the assembly, the Gimbal Bearing on the top center of the assembly, the Electrical Interface Panel sits just below the Gimbal Bearing and the Low-Pressure Oxidizer Turbopump is mounted on the top right of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  1. Studies and analyses of the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Tischer, Alan E.; Glover, R. C.

    1987-01-01

    The primary objectives were to: evaluate ways to maximize the information yield from the current Space Shuttle Main Engine (SSME) condition monitoring sensors, identify additional sensors or monitoring capabilities which would significantly improve SSME data, and provide continuing support of the Main Engine Cost/Operations (MECO) model. In the area of SSME condition monitoring, the principal tasks were a review of selected SSME failure data, a general survey of condition monitoring, and an evaluation of the current engine monitoring system. A computerized data base was developed to assist in modeling engine failure information propagations. Each of the above items is discussed in detail. Also included is a brief discussion of the activities conducted in support of the MECO model.

  2. A simplified dynamic model of the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Duyar, Ahmet; Eldem, Vasfi; Merrill, Walter; Guo, Ten-Huei

    1991-01-01

    A simplified model is presented of the space shuttle main engine (SSME) dynamics valid within the range of operation of the engine. This model is obtained by linking the linearized point models obtained at 25 different operating points of SSME. The simplified model was developed for use with a model-based diagnostic scheme for failure detection and diagnostics studies, as well as control design purposes.

  3. Structural dynamic analysis of the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Scott, L. P.; Jamison, G. T.; Mccutcheon, W. A.; Price, J. M.

    1981-01-01

    This structural dynamic analysis supports development of the SSME by evaluating components subjected to critical dynamic loads, identifying significant parameters, and evaluating solution methods. Engine operating parameters at both rated and full power levels are considered. Detailed structural dynamic analyses of operationally critical and life limited components support the assessment of engine design modifications and environmental changes. Engine system test results are utilized to verify analytic model simulations. The SSME main chamber injector assembly is an assembly of 600 injector elements which are called LOX posts. The overall LOX post analysis procedure is shown.

  4. Space Shuttle Main Engine Debris Testing Methodology and Impact Tolerances

    NASA Technical Reports Server (NTRS)

    Gradl, Paul R.; Stephens, Walter

    2005-01-01

    In the wake of the Space Shuttle Columbia disaster every effort is being made to determine the susceptibility of Space Shuttle elements to debris impacts. Ice and frost debris is formed around the aft heat shield closure of the orbiter and liquid hydrogen feedlines. This debris has been observed to liberate upon lift-off of the shuttle and presents potentially dangerous conditions to the Space Shuttle Main Engine. This paper describes the testing done to determine the impact tolerance of the Space Shuttle Main Engine nozzle coolant tubes to ice strikes originating from the launch pad or other parts of the shuttle.

  5. Space Shuttle Main Engine 3 install in Endeavor

    NASA Image and Video Library

    2007-01-19

    In Orbiter Processing Facility bay 2, technicians on a Hyster forklift maneuver space shuttle main engine no. 3 into place on Endeavour. Each space shuttle main engine is 14 feet long, weighs about 6,700 pounds, and is 7.5 feet in diameter at the end of the nozzle. The orbiter is scheduled for mission STS-118, targeted for launch on June 28. The mission will be the 22nd flight to the International Space Station, carrying another starboard array, S5, for installation.

  6. Space Shuttle Main Engine 3 install in Endeavor

    NASA Image and Video Library

    2007-01-19

    In Orbiter Processing Facility bay 2, technicians on a Hyster forklift install space shuttle main engine no. 3 into Endeavour. Each space shuttle main engine is 14 feet long, weighs about 6,700 pounds, and is 7.5 feet in diameter at the end of the nozzle. The orbiter is scheduled for mission STS-118, targeted for launch on June 28. The mission will be the 22nd flight to the International Space Station, carrying another starboard array, S5, for installation.

  7. Closeup view of a Space Shuttle Main Engine (SSME) mounted ...

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

    Close-up view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent feature in this view is the Expansion Nozzle . The rings that loop around the nozzle, vertically in this view, add structural stability to the nozzle walls and are referred to Hatbands. The ring on the left most edge of the nozzle is the Coolant Inlet Manifold. The tubes that branch off and connect to the manifold are Coolant Transfer Ducts and the tubes that terminate with a visible opening at the manifold are Drain Lines. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  8. General view of a Space Shuttle Main Engine (SSME) mounted ...

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

    General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent feature in this view is the Expansion Nozzle . The rings that loop around the nozzle, vertically in this view, add structural stability to the nozzle walls and are referred to Hatbands. The ring on the left most edge of the nozzle is the Coolant Inlet Manifold. The tubes that branch off and connect to the manifold are Coolant Transfer Ducts and the tubes that terminate with a visible opening at the manifold are Drain Lines. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  9. Evolved Expandable Launch Vehicle System: RS-68 Main Engine Development

    NASA Astrophysics Data System (ADS)

    Portanova, P. L.; Conley, D. S., , Capt; Lee, N. Y.; Wood, B. K.

    2002-01-01

    Delta IV is one of two competing Evolved Expendable Launch Vehicle (EELV) systems being developed in an industry/United States Government partnership to meet the need for the new era of space transportation for the early decades of the 21st Century. The Boeing Company, Rocketdyne, and United States Air Force have developed a 650 Klbf (2.9 NM) class liquid hydrogen/liquid oxygen main engine for the Delta IV family of EELV. The purpose of this paper is to present the innovative approach to the design, development, testing, and certification of the RS-68 engine over the last several years. With the initial production process underway, RS-68 is implementing additional innovative concepts to produce an affordable main engine, and provide assured access to space. 1) The Aerospace Corporation3) The Aerospace Corporation 2) Captain, United States Air Force4) The Boeing Company/Rocketdyne

  10. 30. Engine controls and valve gear, looking aft on main ...

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

    30. Engine controls and valve gear, looking aft on main (promenade) deck level. Threaded admission valve lift rods (two at immediate left of chronometer) permit adjustment of valve timing in lower and upper admission valves of cylinder (left rod controls lower valve, right rod upper valve). Valve rods are lifted by jaw-like "wipers" during operation. Exhaust valve lift rods and wipers are located to right of chronometer. Crank at extreme right drives valve wiper shaft when engaged to end of eccentric rod, shown under "Crank Indicator" dial. Pair of handles to immediate left of admission valve rods control condenser water valves; handles to right of exhaust valve rods control feedwater flow to boilers from pumps. Gauges indicate boiler pressure (left) and condenser vacuum (right); "Crank Indicator" on wall aids engineer in keeping engine crank off "dead-center" at stop so that engine may be easily restarted. - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT

  11. Holographic flow diagnostics for the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Summarized here are the results of an effort to produce holograms of the exhaust from the Space Shuttle Main Engine (SSME) being tested on a test stand at the Marshall Space Flight Center (MSFC). The effort took place from December 1990 to January 1992, during which seven trips were made from MetroLaser to MSFC. A brief outline of each trip is given. Due to the suspension of the SSME program in Huntsville and unexpected complications in resolving safety issues, the proposed holography system was not operated until November 1991. A NASA 100 mW Argon laser was installed in the holography system for an October engine test while these safety issues were being resolved. A video camera shadowgraph was made during this test, which was shut down prematurely after 20 seconds. System problems precluded successful operation of the holography system until the January 1992 engine test. No hologram resulted during this test due to heavy fog conditions around the engine.

  12. Radial and circumferential flow surveys at the inlet and exit of the Space Shuttle Main Engine High Pressure Fuel Turbine Model

    NASA Technical Reports Server (NTRS)

    Hudson, S. T.; Bordelon, W. J., Jr.; Smith, A. W.; Ramachandran, N.

    1995-01-01

    The main objective of this test was to obtain detailed radial and circumferential flow surveys at the inlet and exit of the SSME High Pressure Fuel Turbine model using three-hole cobra probes, hot-film probes, and a laser velocimeter. The test was designed to meet several objectives. First, the techniques for making laser velocimeter, hot-film probe, and cobra probe measurements in turbine flows were developed and demonstrated. The ability to use the cobra probes to obtain static pressure and, therefore, velocity had to be verified; insertion techniques had to be established for the fragile hot-film probes; and a seeding method had to be established for the laser velocimetry. Once the measurement techniques were established, turbine inlet and exit velocity profiles, temperature profiles, pressure profiles, turbulence intensities, and boundary layer thicknesses were measured at the turbine design point. The blockage effect due to the model inlet and exit total pressure and total temperature rakes on the turbine performance was also studied. A small range of off-design points were run to obtain the profiles and to verify the rake blockage effects off-design. Finally, a range of different Reynolds numbers were run to study the effect of Reynolds number on the various measurements.

  13. 23. BACKING DRUM IN FOREGROUND. MAIN ENGINE STEP DRUM IN ...

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

    23. BACKING DRUM IN FOREGROUND. MAIN ENGINE STEP DRUM IN CENTER. TO RIGHT NOTE CYLINDER, PISTON ROD CROSSHEAD. AT END OF CRANKSHAFT NOTE WRIST PIN AND CRANE DISK. - Dredge CINCINNATI, Docked on Ohio River at foot of Lighthill Street, Pittsburgh, Allegheny County, PA

  14. Experimental uncertainty survey and assessment. [Space Shuttle Main Engine testing

    NASA Technical Reports Server (NTRS)

    Coleman, Hugh W.

    1992-01-01

    An uncertainty analysis and assessment of the specific impulse determination during Space Shuttle Main Engine testing is reported. It is concluded that in planning and designing tests and in interpreting the results of tests, the bias and precision components of experimental uncertainty should be considered separately. Recommendations for future research efforts are presented.

  15. Duct flow nonuniformities for Space Shuttle Main Engine (SSME)

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Analytical capabilities for modeling hot gas flow on the fuel side of the Space Shuttle Main Engines are developed. Emphasis is placed on construction and documentation of a computational grid code for modeling an elliptical two-duct version of the fuel side hot gas manifold. Computational results for flow past a support strut in an annular channel are also presented.

  16. Automatic detection of anomalies in Space Shuttle Main Engine turbopumps

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Whitehead, B. A.; Wu, Kewei

    1992-01-01

    A prototype expert system (developed on both PC and Symbolics 3670 lisp machine) for detecting anomalies in turbopump vibration data has been tested with data from ground tests 902-473, 902-501, 902-519, and 904-097 of the Space Shuttle Main Engine (SSME). The expert system has been utilized to analyze vibration data from each of the following SSME components: high-pressure oxidizer turbopump, high-pressure fuel turbopump, low-pressure fuel turbopump, and preburner boost pump. The expert system locates and classifies peaks in the power spectral density of each 0.4-sec window of steady-state data. Peaks representing the fundamental and harmonic frequencies of both shaft rotation and bearing cage rotation are identified by the expert system. Anomalies are then detected on the basis of sequential criteria and two threshold criteria set individually for the amplitude of each of these peaks: a prior threshold used during the first few windows of data in a test, and a posterior threshold used thereafter. In most cases the anomalies detected by the expert system agree with those reported by NASA. The two cases where there is significant disagreement will be further studied and the system design refined accordingly.

  17. Automatic detection of anomalies in Space Shuttle Main Engine turbopumps

    NASA Astrophysics Data System (ADS)

    Lo, Ching F.; Whitehead, B. A.; Wu, Kewei

    1992-07-01

    A prototype expert system (developed on both PC and Symbolics 3670 lisp machine) for detecting anomalies in turbopump vibration data has been tested with data from ground tests 902-473, 902-501, 902-519, and 904-097 of the Space Shuttle Main Engine (SSME). The expert system has been utilized to analyze vibration data from each of the following SSME components: high-pressure oxidizer turbopump, high-pressure fuel turbopump, low-pressure fuel turbopump, and preburner boost pump. The expert system locates and classifies peaks in the power spectral density of each 0.4-sec window of steady-state data. Peaks representing the fundamental and harmonic frequencies of both shaft rotation and bearing cage rotation are identified by the expert system. Anomalies are then detected on the basis of sequential criteria and two threshold criteria set individually for the amplitude of each of these peaks: a prior threshold used during the first few windows of data in a test, and a posterior threshold used thereafter. In most cases the anomalies detected by the expert system agree with those reported by NASA. The two cases where there is significant disagreement will be further studied and the system design refined accordingly.

  18. Research Study: Space Shuttle Main Engine Plume Flowfield Model

    NASA Technical Reports Server (NTRS)

    Bender, Robert L.

    1988-01-01

    The initial research effort was an in-depth analysis of the shuttle main engine plumes in an effort to improve the flowfield model and to enhance shuttle base heating equipment predictions during ascent. A prediction methodology code was developed incorporating the improved plume model into a predictive tool which could consider different trajectoreis and engine perfromance variables. Various plume flow model improvement studies were ongoing at the time of the 51-L accident. Since that time, base heating and plume methodology improvements have continued as part of the overall emphasis on Shuttle design assurance before resuming flight schedule.

  19. Evolved expendable launch vehicle system: RS-68 main engine development

    NASA Astrophysics Data System (ADS)

    Conley, David; Lee, Norman Y.; Portanova, Peter L.; Wood, Byron K.

    2003-08-01

    Delta IV is one of two competing Evolved Expendable Launch Vehicle (EELV) systems being developed in an industry/United States Government partnership to meet the needs of the new era of space launch for the early decades of the 21 st Century. The Rocketdyne Division of The Boeing Company and the United States Air Force have developed a 650 Klbf sea-level (2.9 MN) class liquid hydrogen/liquid oxygen main engine for the Delta IV family of EELV. The purpose of this paper is to present the innovative approach to the design, development, testing and certification of the RS-68 engine.

  20. Nonlinear rotordynamics analysis. [Space Shuttle Main Engine turbopumps

    NASA Technical Reports Server (NTRS)

    Noah, Sherif T.

    1991-01-01

    Effective analysis tools were developed for predicting the nonlinear rotordynamic behavior of the Space Shuttle Main Engine (SSME) turbopumps under steady and transient operating conditions. Using these methods, preliminary parametric studies were conducted on both generic and actual HPOTP (high pressure oxygen turbopump) models. In particular, a novel modified harmonic balance/alternating Fourier transform (HB/AFT) method was developed and used to conduct a preliminary study of the effects of fluid, bearing and seal forces on the unbalanced response of a multi-disk rotor in the presence of bearing clearances. The method makes it possible to determine periodic, sub-, super-synchronous and chaotic responses of a rotor system. The method also yields information about the stability of the obtained response, thus allowing bifurcation analyses. This provides a more effective capability for predicting the response under transient conditions by searching in proximity of resonance peaks. Preliminary results were also obtained for the nonlinear transient response of an actual HPOTP model using an efficient, newly developed numerical method based on convolution integration. Currently, the HB/AFT is being extended for determining the aperiodic response of nonlinear systems. Initial results show the method to be promising.

  1. Automatic detection of anomalies in Space Shuttle Main Engine turbopumps

    NASA Technical Reports Server (NTRS)

    Lo, Ching F. (Principal Investigator); Whitehead, Bruce; Wu, Kewei; Rogers, George

    1992-01-01

    A prototype expert system for detecting anomalies in turbopump vibration data has been tested with data from ground tests 902-473, 902-501 902-519, and 904-097 of the Space Shuttle Main Engine!nc (SSME). The expert system has been utilized to analyze vibration ion data from each of the following SSME components: pressure oxidizer turbopump, high-pressure fuel turbo pump, low-pressure fuel turbopump, and preburner boost pump. The expert system locates and classifies peaks in the power spectral density of each 0.4 s window of steady-state data. Peaks representing the fundamental and harmonic frequencies of both shaft rotation and bearing cage rotation are identified by the expert system. Anomalies are then detected on the basis of of two thresholds set individually for the amplitude of each of these peaks: a prior threshold used during the first few windows of data in a test, and a posterior threshold used thereafter. In most cases the anomalies detected by the expert system agree with those reported by NASA. The two cases where there is significant disagreement will be further studied and the system design refined accordingly.

  2. TVC actuator model. [for the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Baslock, R. W.

    1977-01-01

    A prototype Space Shuttle Main Engine (SSME) Thrust Vector Control (TVC) Actuator analog model was successfully completed. The prototype, mounted on five printed circuit (PC) boards, was delivered to NASA, checked out and tested using a modular replacement technique on an analog computer. In all cases, the prototype model performed within the recording techniques of the analog computer which is well within the tolerances of the specifications.

  3. 27. VIEW FROM AFT OF MAIN HOISTING ENGINE WITH HOISTING ...

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

    27. VIEW FROM AFT OF MAIN HOISTING ENGINE WITH HOISTING DRUM IN FOREGROUND. NOTE MAIN HOISTING DRUM IS A STEP DRUM, WITH TWO DIAMETERS ON DRUM. WHEN BUCKET IS IN WATER THE CABLE IS ON THE SMALLER STEP, AS PICTURED, GIVING MORE POWER TO THE LINE. THE CABLE STEPS TO LARGER DIAMETER WHEN BUCKET IS OUT OF WATER, WHERE SPEED IS MORE IMPORTANT THAN POWER. SMALLER BACKING DRUM IN BACKGROUND. - Dredge CINCINNATI, Docked on Ohio River at foot of Lighthill Street, Pittsburgh, Allegheny County, PA

  4. Lox/Gox related failures during Space Shuttle Main Engine development

    NASA Technical Reports Server (NTRS)

    Cataldo, C. E.

    1981-01-01

    Specific rocket engine hardware and test facility system failures are described which were caused by high pressure liquid and/or gaseous oxygen reactions. The failures were encountered during the development and testing of the space shuttle main engine. Failure mechanisms are discussed as well as corrective actions taken to prevent or reduce the potential of future failures.

  5. Investigations of ice formation in the Space Shuttle Main Engine 0209 main injector coolant cavity

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Charklwick, D. M.

    1991-01-01

    Severe main combustion chamber wall and main injector baffle element deterioration occurred during tests of Space Shuttle Main Engine 0209. One of the possible causes considered is ice formation and blockage of coolant to these components, resulting from the mixing of leaking hot turbine exhaust gas (hydrogen rich steam) and hydrogen coolant in the injector coolant cavity. The plausibility of ice blockage is investigated through simple mixing calculations for hot gas and hydrogen, investigation of condensation and water droplet formation, calculation of the freezing times for droplets, and the prediction of ice layer thicknesses. It is concluded that condensation and droplet formation can occur, and small water droplets that form can freeze very quickly when in contact with the cold coolant cavity surfaces. Copnservative analysis predicts, however, that the maximum thickness of the ice layers formed is too small to result in significant blockage of the coolant flow.

  6. Investigations of ice formation in the Space Shuttle Main Engine 0209 main injector coolant cavity

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Charklwick, D. M.

    1991-01-01

    Severe main combustion chamber wall and main injector baffle element deterioration occurred during tests of Space Shuttle Main Engine 0209. One of the possible causes considered is ice formation and blockage of coolant to these components, resulting from the mixing of leaking hot turbine exhaust gas (hydrogen rich steam) and hydrogen coolant in the injector coolant cavity. The plausibility of ice blockage is investigated through simple mixing calculations for hot gas and hydrogen, investigation of condensation and water droplet formation, calculation of the freezing times for droplets, and the prediction of ice layer thicknesses. It is concluded that condensation and droplet formation can occur, and small water droplets that form can freeze very quickly when in contact with the cold coolant cavity surfaces. Copnservative analysis predicts, however, that the maximum thickness of the ice layers formed is too small to result in significant blockage of the coolant flow.

  7. Study of methods for applying and enhancing transfer film coatings of polytetrafluoroethylene (PTEE) to Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbo Pump (HPOTP) bearings

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Dufrane, K. F.; Zugaro, F. F.

    1981-01-01

    Machines were constructed and evaluated for burnishing polytetrafluoroethylene on balls for use in the high pressure oxygen turbopump (HPOTP). The most positive performance was obtained with single-ball burnishing, but one technique for burnishing three balls simultaneously holds promise. Evaluations of the coatings in a HPOTP bearing of earlier design (employed smaller diameter balls) showed very little life enhancement before high torque and ball and race wear initiated. Other coating techniques, such as molybdenum disulfide combined with PTFE transfer films, hold promise for providing the more durable quantities of solid lubricant needed for the bearings.

  8. Liquid Oxygen/Liquid Methane Ascent Main Engine Technology Development

    NASA Technical Reports Server (NTRS)

    Robinson, Joel W.; Stephenson, David D.

    2008-01-01

    The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LO2)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon the Exploration Systems Architecture Study (ESAS). The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. The current application considering this technology is the lunar ascent main engine (AME). AME is anticipated to be an expendable, pressure-fed engine to provide ascent from the moon at the completion of a 210 day lunar stay. The engine is expected to produce 5,500 lbf (24,465 N) thrust with variable inlet temperatures due to the cryogenic nature of the fuel and oxidizer. The primary technology risks include establishing reliable and robust ignition in vacuum conditions, maximizing specific impulse, developing rapid start capability for the descent abort, providing the capability for two starts and producing a total engine bum time over 500 seconds. This paper will highlight the efforts of the Marshall Space Flight Center (MSFC) in addressing risk reduction activities for this technology.

  9. A Basic Comparison of the Space Shuttle Main Engine and the J-2X Engine

    NASA Technical Reports Server (NTRS)

    Ayer, Adam

    2007-01-01

    With the introduction of the new manned space effort through the Constellation Program, there is an interest to have a basic comparison of the current Space Shuttle Main Engine (SSME) to the J-2X engine used for the second stage of both the Ares I and Ares V rockets. This paper seeks to compare size, weight and thrust capabilities while drawing simple conclusions on differences between the two engines.

  10. Numerical thermal analyses that contributed to the elimination of turbine blade firtree cracks in the Space Shuttle Main Engine High Pressure Fuel Turbopump turbine

    NASA Technical Reports Server (NTRS)

    Principe, R. S.; Behne, D. S.

    1988-01-01

    NASA-Marshall has undertaken analytical and experimental efforts to eliminate all turbine blade cracking and further improve the safety and reliability of the SSME. This work is focused on the elimination of cracks at the blade firtree attachment to the disk, in both the first- and second-stage rotors of the High Pressure Fuel Turbopump. Emphasis is placed on thermal analyses that preceded the overall structural evaluation of the blade firtrees. Thermally-induced contributions to the stresses and strains in the firtrees were quantified by these studies, and feasible design improvement options were identified and tested.

  11. First-ever evening public engine test of a Space Shuttle Main Engine

    NASA Image and Video Library

    2001-04-21

    Thousands of people watch the first-ever evening public engine test of a Space Shuttle Main Engine at NASA's John C. Stennis Space Center. The spectacular test marked Stennis Space Center's 20th anniversary celebration of the first Space Shuttle mission.

  12. Space Shuttle Main Engine nozzle thermal protection system

    NASA Technical Reports Server (NTRS)

    Nordlund, R. M.

    1985-01-01

    Two of the three Space Shuttle Main Engine (SSME) nozzles are exposed to significant reentry aeroheating loads. To ensure reusability of the Nozzle Assembly, the nozzle primary structure must not exceed specific temperature limits. Due to the thermal, pressure, and dynamic flexing of the nozzle during a mission cycle, an appropriate insulating system must have significant flexibility. Recent missions have demonstrated nozzle reentry aeroheating rates and heat loads much higher than predictions, higher than the capability of the original insulating system. A new insulating system has been developed using similar materials in an aerodynamically 'smooth' shape to both reduce the incoming heating and increase radiation cooling.

  13. Space Shuttle Main Engine nozzle thermal protection system

    NASA Technical Reports Server (NTRS)

    Nordlund, R. M.

    1985-01-01

    Two of the three Space Shuttle Main Engine (SSME) nozzles are exposed to significant reentry aeroheating loads. To ensure reusability of the Nozzle Assembly, the nozzle primary structure must not exceed specific temperature limits. Due to the thermal, pressure, and dynamic flexing of the nozzle during a mission cycle, an appropriate insulating system must have significant flexibility. Recent missions have demonstrated nozzle reentry aeroheating rates and heat loads much higher than predictions, higher than the capability of the original insulating system. A new insulating system has been developed using similar materials in an aerodynamically 'smooth' shape to both reduce the incoming heating and increase radiation cooling.

  14. Non-intrusive speed sensor. [space shuttle main engine turbopumps

    NASA Technical Reports Server (NTRS)

    Maram, J.; Wyett, L.

    1984-01-01

    A computerized literature search was performed to identify candidate technologies for remote, non-intrusive speed sensing applications in Space Shuttle Main Engine (SSME) turbopumps. The three most promising technologies were subjected to experimental evaluation to quantify their performance characteristics under the harsh environmental requirements within the turbopumps. Although the infrared and microwave approaches demonstrated excellent cavitation immunity in laboratory tests, the variable-source magnetic speed sensor emerged as the most viable approach. Preliminary design of this speed sensor encountered no technical obstacles and resulted in viable and feasible speed nut, sensor housing, and sensor coil designs.

  15. Space shuttle main engine fault detection using neural networks

    NASA Technical Reports Server (NTRS)

    Bishop, Thomas; Greenwood, Dan; Shew, Kenneth; Stevenson, Fareed

    1991-01-01

    A method for on-line Space Shuttle Main Engine (SSME) anomaly detection and fault typing using a feedback neural network is described. The method involves the computation of features representing time-variance of SSME sensor parameters, using historical test case data. The network is trained, using backpropagation, to recognize a set of fault cases. The network is then able to diagnose new fault cases correctly. An essential element of the training technique is the inclusion of randomly generated data along with the real data, in order to span the entire input space of potential non-nominal data.

  16. Research pressure instrumentation for NASA space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Anderson, P. J.; Nussbaum, P.; Gustafson, G.

    1985-01-01

    The breadboard feasibility model of a silicon piezoresistive pressure transducer suitable for space shuttle main engine (SSME) applications was demonstrated. The development of pressure instrumentation for the SSME was examined. The objective is to develop prototype pressure transducers which are targeted to meet the SSME performance design goals and to fabricate, test and deliver a total of 10 prototype units. Effective utilization of the many advantages of silicon piezoresistive strain sensing technology to achieve the objectives of advanced state-of-the-art pressure sensors for reliability, accuracy and ease of manufacture is analyzed. Integration of multiple functions on a single chip is the key attribute of the technology.

  17. Aft Engine shop worker removes a heat shield on Columbia's main engines

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Doug Buford (top), with the Aft Engine shop, along with another worker, removes a heat shield on one of Columbia's engines. After small cracks were discovered on the LH2 Main Propulsion System (MPS) flow liners in two other orbiters, program managers decided to move forward with inspections on Columbia before clearing it for flight on STS-107. After removal of the heat shields, the three main engines will be removed. Inspections of the flow liners will follow. The July 19 launch of Columbia on STS-107 has been delayed a few weeks

  18. Space Shuttle Main Engine (SSME) Systems Operation Overview and Evolution

    NASA Technical Reports Server (NTRS)

    Benefield, Philip A.; Kan, Kenneth C.

    2010-01-01

    The Space Shuttle Main Engine (SSME) is a large thrust class, reusable, staged combustion cycle rocket engine employing liquid hydrogen and liquid oxygen propellants. A cluster of three SSMEs is used on every space shuttle mission to propel the space shuttle orbiter vehicle into low earth orbit. Development of the SSME began in the early 70's and the first flight of the space shuttle occurred in 1981. Today, the SSME has accrued over one million seconds of ground test and flight operational time, launching 129 space shuttle missions. The systems operation of the SSME was developed and evolved to support the specific requirements of the Space Shuttle Program (SSP). This paper provides a systems operation overview of the SSME, including: engine cycle, propellant flowpaths, and major components; control system; operations during pre-start, start, mainstage, and shutdown phases; launch commit criteria (LCCs) and operational redlines. Furthermore, this paper will discuss how changes to the SSME over its history have impacted systems operations.

  19. Summary of Results from Space Shuttle Main Engine Off-Nominal Testing

    NASA Technical Reports Server (NTRS)

    Horton, James F.; Megivern, Jeffrey M.; McNutt, Leslie M.

    2011-01-01

    This paper is a summary of Space Shuttle Main Engine (SSME) off-nominal testing that occurred during 2008 and 2009. During the last two years of planned SSME testing at Stennis Space Center, Pratt & Whitney Rocketdyne worked with their NASA MSFC customer to systematically identify, develop, assess, and implement challenging test objectives in order to expand the knowledge of one of the world s most reliable and highly tested large rocket engine. The objectives successfully investigated three main areas of interest expanding engine performance margins, demonstrating system operational capabilities, and establishing ground work for new rocket engine technology. The testing gave the Space Shuttle Program new options to safely fly out the flight manifest and provided Pratt & Whitney Rocketdyne and NASA new insight into the operational capabilities of the SSME, capabilities which can be used in assessing potential future applications of the RS-25 engine.

  20. A History of Welding on the Space Shuttle Main Engine (1975 to 2010)

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank R.; Russell, Carolyn K.

    2010-01-01

    The Space Shuttle Main Engine (SSME) is a high performance, throttleable, liquid hydrogen fueled rocket engine. High thrust and specific impulse (Isp) are achieved through a staged combustion engine cycle, combined with high combustion pressure (approx.3000psi) generated by the two-stage pump and combustion process. The SSME is continuously throttleable from 67% to 109% of design thrust level. The design criteria for this engine maximize performance and weight, resulting in a 7,800 pound rocket engine that produces over a half million pounds of thrust in vacuum with a specific impulse of 452/sec. It is the most reliable rocket engine in the world, accumulating over one million seconds of hot-fire time and achieving 100% flight success in the Space Shuttle program. A rocket engine with the unique combination of high reliability, performance, and reusability comes at the expense of manufacturing simplicity. Several innovative design features and fabrication techniques are unique to this engine. This is as true for welding as any other manufacturing process. For many of the weld joints it seemed mean cheating physics and metallurgy to meet the requirements. This paper will present a history of the welding used to produce the world s highest performance throttleable rocket engine.

  1. Space Shuttle Main Engine modal test correlation and optimization

    NASA Astrophysics Data System (ADS)

    Stec, Robert C.; Gupta, Viney K.; Chaney, Lisa; Haworth, John M.

    1993-04-01

    A cost-effective software testbed under development is described for updating and validating Finite-Element Models (FEMs) to certify large-scale Space Shuttle Main Engine (SSME) STARDYNE and NASTRAN FEMs against modal test data. The long-term objectives of the testbed are to provide timely support and certification of SSME components using modal testing: certify large-scale structures such as the SSME using modal survey tests, update FEMs for model validation against test frequencies and mode shapes, verify the load factors for design loads assumed to determine structural integrity, demonstrate the Rocketdyne software testbed based on state-of-the art methods - optimization, static/dynamic reduction, sparse Lanczos solvers and iterative perturbation algorithms, and to identify future enhancements and applications for the National Aeronautics and Space Administration (NASA)-Rocketdyne testbed "FEMOPT" developed for Space Station and SSME model certification.

  2. The reusable Space Shuttle Main Engine prepares for long life

    NASA Technical Reports Server (NTRS)

    Klatt, F. P., Jr.; Wheelock, V. J.

    1982-01-01

    Attention is given to Space Shuttle Main Engine (SSME) life extension and logistical systems that support launch and ground operations. The operations and maintenance tasks involved in this aspect of SSME development include turnaround requirements, ground support equipment, and control documentation. A discussion is presented on the spare parts provisioning system, which emphasizes the source of decision-making data and encompasses the hardware tracking system, usage data from ground testing and launch operations, and current and projected life limits. The life extension test program leads the launch program, offering comfortable life limit margins. Planned overhauls for the extension of useful hardware life beyond the 55-mission requirement, a turnabout improvement program, and a continuous training program contribute to launch cost reductions, reliable operations, and long life.

  3. A failure diagnosis system based on a neural network classifier for the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Duyar, Ahmet; Merrill, Walter

    1990-01-01

    A conceptual design of a model based failure detection and diagnosis system is developed for the space shuttle main engine. This design relies on the accurate and reliable identification of the parameters of the highly nonlinear and very complex engine. The design approach is presented in some detail and results for a failed valve are presented. These preliminary results verify that the developed parameter identification technique together with a neural network classifier can be used for this purpose.

  4. Aft Engine shop worker removes a heat shield on Columbia's main engines

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Doug Buford, with the Aft Engine shop, works at removing a heat shield on Columbia, in the Orbiter Processing Facility. After small cracks were discovered on the LH2 Main Propulsion System (MPS) flow liners in two other orbiters, program managers decided to move forward with inspections on Columbia before clearing it for flight on STS-107. After removal of the heat shields, the three main engines will be removed. Inspections of the flow liners will follow. The July 19 launch of Columbia on STS-107 has been delayed a few weeks

  5. Aft Engine shop worker removes a heat shield on Columbia's main engines

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - Doug Buford, with the Aft Engine shop, works at removing a heat shield on Columbia, in the Orbiter Processing Facility. After small cracks were discovered on the LH2 Main Propulsion System (MPS) flow liners in two other orbiters, program managers decided to move forward with inspections on Columbia before clearing it for flight on STS-107. After removal of the heat shields, the three main engines will be removed. Inspections of the flow liners will follow. The July 19 launch of Columbia on STS-107 has been delayed a few weeks

  6. Embedded expert system for space shuttle main engine maintenance

    NASA Technical Reports Server (NTRS)

    Pooley, J.; Thompson, W.; Homsley, T.; Teoh, W.; Jones, J.; Lewallen, P.

    1987-01-01

    The SPARTA Embedded Expert System (SEES) is an intelligent health monitoring system that directs analysis by placing confidence factors on possible engine status and then recommends a course of action to an engineer or engine controller. The technique can prevent catastropic failures or costly rocket engine down time because of false alarms. Further, the SEES has potential as an on-board flight monitor for reusable rocket engine systems. The SEES methodology synergistically integrates vibration analysis, pattern recognition and communications theory techniques with an artificial intelligence technique - the Embedded Expert System (EES).

  7. Duct flow nonuniformities for Space Shuttle Main Engine (SSME)

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A three-duct Space Shuttle Main Engine (SSME) Hot Gas Manifold geometry code was developed for use. The methodology of the program is described, recommendations on its implementation made, and an input guide, input deck listing, and a source code listing provided. The code listing is strewn with an abundance of comments to assist the user in following its development and logic. A working source deck will be provided. A thorough analysis was made of the proper boundary conditions and chemistry kinetics necessary for an accurate computational analysis of the flow environment in the SSME fuel side preburner chamber during the initial startup transient. Pertinent results were presented to facilitate incorporation of these findings into an appropriate CFD code. The computation must be a turbulent computation, since the flow field turbulent mixing will have a profound effect on the chemistry. Because of the additional equations demanded by the chemistry model it is recommended that for expediency a simple algebraic mixing length model be adopted. Performing this computation for all or selected time intervals of the startup time will require an abundance of computer CPU time regardless of the specific CFD code selected.

  8. Analysis of the Space Shuttle main engine simulation

    NASA Technical Reports Server (NTRS)

    Deabreu-Garcia, J. Alex; Welch, John T.

    1993-01-01

    This is a final report on an analysis of the Space Shuttle Main Engine Program, a digital simulator code written in Fortran. The research was undertaken in ultimate support of future design studies of a shuttle life-extending Intelligent Control System (ICS). These studies are to be conducted by NASA Lewis Space Research Center. The primary purpose of the analysis was to define the means to achieve a faster running simulation, and to determine if additional hardware would be necessary for speeding up simulations for the ICS project. In particular, the analysis was to consider the use of custom integrators based on the Matrix Stability Region Placement (MSRP) method. In addition to speed of execution, other qualities of the software were to be examined. Among these are the accuracy of computations, the useability of the simulation system, and the maintainability of the program and data files. Accuracy involves control of truncation error of the methods, and roundoff error induced by floating point operations. It also involves the requirement that the user be fully aware of the model that the simulator is implementing.

  9. Framework for a space shuttle main engine health monitoring system

    NASA Technical Reports Server (NTRS)

    Hawman, Michael W.; Galinaitis, William S.; Tulpule, Sharayu; Mattedi, Anita K.; Kamenetz, Jeffrey

    1990-01-01

    A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available.

  10. Combustion Stability Characteristics of the Project Morpheus Liquid Oxygen / Liquid Methane Main Engine

    NASA Technical Reports Server (NTRS)

    Melcher, John C.; Morehead, Robert L.

    2014-01-01

    The project Morpheus liquid oxygen (LOX) / liquid methane (LCH4) main engine is a Johnson Space Center (JSC) designed 5,000 lbf-thrust, 4:1 throttling, pressure-fed cryogenic engine using an impinging element injector design. The engine met or exceeded all performance requirements without experiencing any in- ight failures, but the engine exhibited acoustic-coupled combustion instabilities during sea-level ground-based testing. First tangential (1T), rst radial (1R), 1T1R, and higher order modes were triggered by conditions during the Morpheus vehicle derived low chamber pressure startup sequence. The instability was never observed to initiate during mainstage, even at low power levels. Ground-interaction acoustics aggravated the instability in vehicle tests. Analysis of more than 200 hot re tests on the Morpheus vehicle and Stennis Space Center (SSC) test stand showed a relationship between ignition stability and injector/chamber pressure. The instability had the distinct characteristic of initiating at high relative injection pressure drop at low chamber pressure during the start sequence. Data analysis suggests that the two-phase density during engine start results in a high injection velocity, possibly triggering the instabilities predicted by the Hewitt stability curves. Engine ignition instability was successfully mitigated via a higher-chamber pressure start sequence (e.g., 50% power level vs 30%) and operational propellant start temperature limits that maintained \\cold LOX" and \\warm methane" at the engine inlet. The main engine successfully demonstrated 4:1 throttling without chugging during mainstage, but chug instabilities were observed during some engine shutdown sequences at low injector pressure drop, especially during vehicle landing.

  11. Project Morpheus Main Engine Development and Preliminary Flight Testing

    NASA Technical Reports Server (NTRS)

    Morehead, Robert L.

    2011-01-01

    A LOX/Methane rocket engine was developed for a prototype terrestrial lander and then used to fly the lander at Johnson Space Center. The development path of this engine is outlined, including unique items such as variable acoustic damping and variable film cooling.

  12. Design considerations for a Space Shuttle Main Engine turbine blade made of single crystal material

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, A.; August, R.; Nagpal, V.

    1993-01-01

    Nonlinear finite-element structural analyses were performed on the first stage high-pressure fuel turbopump blade of the Space Shuttle Main Engine. The analyses examined the structural response and the dynamic characteristics at typical operating conditions. Single crystal material PWA-1480 was considered for the analyses. Structural response and the blade natural frequencies with respect to the crystal orientation were investigated. The analyses were conducted based on typical test stand engine cycle. Influence of combined thermal, aerodynamic, and centrifugal loadings was considered. Results obtained showed that the single crystal secondary orientation effects on the maximum principal stresses are not highly significant.

  13. High Efficiency Engine Technologies Program

    SciTech Connect

    Rich Kruiswyk

    2010-07-13

    Caterpillar's Product Development and Global Technology Division carried out a research program on waste heat recovery with support from DOE (Department of Energy) and the DOE National Energy Technology Laboratory. The objective of the program was to develop a new air management and exhaust energy recovery system that would demonstrate a minimum 10% improvement in thermal efficiency over a base heavy-duty on-highway diesel truck engine. The base engine for this program was a 2007 C15 15.2L series-turbocharged on-highway truck engine with a LPL (low-pressure loop) exhaust recirculation system. The focus of the program was on the development of high efficiency turbomachinery and a high efficiency turbocompound waste heat recovery system. The focus of each area of development was as follows: (1) For turbine stages, the focus was on investigation and development of technologies that would improve on-engine exhaust energy utilization compared to the conventional radial turbines in widespread use today. (2) For compressor stages, the focus was on investigating compressor wheel design parameters beyond the range typically utilized in production, to determine the potential efficiency benefits thereof. (3) For turbocompound, the focus was on the development of a robust bearing system that would provide higher bearing efficiencies compared to systems used in turbocompound power turbines in production. None of the turbocharger technologies investigated involved addition of moving parts, actuators, or exotic materials, thereby increasing the likelihood of a favorable cost-value tradeoff for each technology. And the turbocompound system requires less hardware addition than competing bottoming cycle technologies, making it a more attractive solution from a cost and packaging standpoint. Main outcomes of the program are as follows: (1) Two turbine technologies that demonstrated up to 6% improvement in turbine efficiency on gas stand and 1-3% improvement in thermal efficiency in

  14. 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.

  15. Combustion Stability Characteristics of the Project Morpheus Liquid Oxygen/Liquid Methane Main Engine

    NASA Technical Reports Server (NTRS)

    Melcher, J. C.; Morehead, Robert L.

    2014-01-01

    The Project Morpheus liquid oxygen (LOX) / liquid methane rocket engines demonstrated acousticcoupled combustion instabilities during sea-level ground-based testing at the NASA Johnson Space Center (JSC) and Stennis Space Center (SSC). High-amplitude, 1T, 1R, 1T1R (and higher order) modes appear to be triggered by injector conditions. The instability occurred during the Morpheus-specific engine ignition/start sequence, and did demonstrate the capability to propagate into mainstage. However, the instability was never observed to initiate during mainstage, even at low power levels. The Morpheus main engine is a JSC-designed 5,000 lbf-thrust, 4:1 throttling, pressure-fed cryogenic engine using an impinging element injector design. Two different engine designs, named HD4 and HD5, and two different builds of the HD4 engine all demonstrated similar instability characteristics. Through the analysis of more than 200 hot fire tests on the Morpheus vehicle and SSC test stand, a relationship between ignition stability and injector/chamber pressure was developed. The instability has the distinct characteristic of initiating at high relative injection pressure drop (dP) at low chamber pressure (Pc); i.e., instabilities initiated at high dP/Pc at low Pc during the start sequence. The high dP/Pc during start results during the injector /chamber chill-in, and is enhanced by hydraulic flip in the injector orifice elements. Because of the fixed mixture ratio of the existing engine design (the main valves share a common actuator), it is not currently possible to determine if LOX or methane injector dP/Pc were individual contributors (i.e., LOX and methane dP/Pc typically trend in the same direction within a given test). The instability demonstrated initiation characteristic of starting at or shortly after methane injector chillin. Colder methane (e.g., sub-cooled) at the injector inlet prior to engine start was much more likely to result in an instability. A secondary effect of LOX

  16. Multidisciplinary analysis of Skylab photography for highway engineering purposes. [Maine

    NASA Technical Reports Server (NTRS)

    Stoeckeler, E. G.; Woodman, R. G. (Principal Investigator); Farrell, R. S.

    1975-01-01

    The author has identified the following significant results. The greatly increased resolution of ground features by Skylab as compared with LANDSAT is considered to be best in the S190B high resolution film, followed by S190A camera stations 4, 5, and 6 respectfully. Results of the study of vegetation damage sites using data derived from S190A film were disappointing. The major cause of detection problems is the graininess of the CIR film. Good results were achieved for the hydrology-land use study. Both camera systems gave better agreement with the ground truth than did LANDSAT imagery. Surficial geology and glacial landform areas were clearly visible in single scenes. Several previously unmapped or unknown features were detected, especially in eastern coastal Maine.

  17. Thermal-structural analyses of Space Shuttle Main Engine (SSME) hot section components

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali; Thompson, Robert L.

    1988-01-01

    Three dimensional nonlinear finite element heat transfer and structural analyses were performed for the first stage high pressure fuel turbopump (HPFTP) blade of the space shuttle main engine (SSME). Directionally solidified (DS) MAR-M 246 and single crystal (SC) PWA-1480 material properties were used for the analyses. Analytical conditions were based on a typical test stand engine cycle. Blade temperature and stress strain histories were calculated by using the MARC finite element computer code. The structural response of an SSME turbine blade was assessed and a greater understanding of blade damage mechanisms, convective cooling effects, and thermal mechanical effects was gained.

  18. Thermal finite-element analysis of space shuttle main engine turbine blade

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali; Tong, Michael T.; Kaufman, Albert

    1987-01-01

    Finite-element, transient heat transfer analyses were performed for the first-stage blades of the space shuttle main engine (SSME) high-pressure fuel turbopump. The analyses were based on test engine data provided by Rocketdyne. Heat transfer coefficients were predicted by performing a boundary-layer analysis at steady-state conditions with the STAN5 boundary-layer code. Two different peak-temperature overshoots were evaluated for the startup transient. Cutoff transient conditions were also analyzed. A reduced gas temperature profile based on actual thermocouple data was also considered. Transient heat transfer analyses were conducted with the MARC finite-element computer code.

  19. Rocket Science: The Shuttle's Main Engines, though Old, Are not Forgotten in the New Exploration Initiative

    NASA Technical Reports Server (NTRS)

    Covault, Craig

    2005-01-01

    The Space Shuttle Main Engine (SSME), developed 30 years ago, remains a strong candidate for use in the new Exploration Initiative as part of a shuttle-derived heavy-lift expendable booster. This is because the Boeing-Rocket- dyne man-rated SSME remains the most highly efficient liquid rocket engine ever developed. There are only enough parts for 12-15 existing SSMEs, however, so one NASA option is to reinitiate SSME production to use it as a throw-away, as opposed to a reusable, powerplant for NASA s new heavy-lift booster.

  20. Thin film heat flux sensor for Space Shuttle Main Engine turbine environment

    NASA Astrophysics Data System (ADS)

    Will, Herbert

    1991-05-01

    The Space Shuttle Main Engine (SSME) turbine environment stresses engine components to their design limits and beyond. The extremely high temperatures and rapid temperature cycling can easily cause parts to fail if they are not properly designed. Thin film heat flux sensors can provide heat loading information with almost no disturbance of gas flows or of the blade. These sensors can provide steady state and transient heat flux information. A thin film heat flux sensor is described which makes it easier to measure small temperature differences across very thin insulating layers.

  1. Rocket Science: The Shuttle's Main Engines, though Old, Are not Forgotten in the New Exploration Initiative

    NASA Technical Reports Server (NTRS)

    Covault, Craig

    2005-01-01

    The Space Shuttle Main Engine (SSME), developed 30 years ago, remains a strong candidate for use in the new Exploration Initiative as part of a shuttle-derived heavy-lift expendable booster. This is because the Boeing-Rocket- dyne man-rated SSME remains the most highly efficient liquid rocket engine ever developed. There are only enough parts for 12-15 existing SSMEs, however, so one NASA option is to reinitiate SSME production to use it as a throw-away, as opposed to a reusable, powerplant for NASA s new heavy-lift booster.

  2. Space Shuttle main engine turbopump bearing assessment program

    NASA Technical Reports Server (NTRS)

    Breithaupt, B. Spiegel

    1994-01-01

    This report documents the work done on the bearing assessment program over the past two and a half years. The objective of the program is to develop a nondestructive evaluation system for the SSME HPOTP's which would be used to detect anomalies in installed bearings without engine disassembly. Data bases of various signatures are obtained by slowly turning the pump shafts before and after an engine firing. These signatures are then analyzed and compared to the original signatures to more accurately predict bearing wear.

  3. Space Shuttle Main Engine Joint Data List Applying Today's Desktop Technologies to Facilitate Engine Processing

    NASA Technical Reports Server (NTRS)

    Jacobs, Kenneth; Drobnick, John; Krell, Don; Neuhart, Terry; McCool, A. (Technical Monitor)

    2001-01-01

    Boeing-Rocketdyne's Space Shuttle Main Engine (SSME) is the world's first large reusable liquid rocket engine. The space shuttle propulsion system has three SSMEs, each weighing 7,400 lbs and providing 470,000 lbs of thrust at 100% rated power level. To ensure required safety and reliability levels are achieved with the reusable engines, each SSME is partially disassembled, inspected, reassembled, and retested at Kennedy Space Center between each flight. Maintenance processing must be performed very carefully to replace any suspect components, maintain proper engine configuration, and avoid introduction of contaminants that could affect performance and safety. The long service life, and number, complexity, and pedigree of SSME components makes logistics functions extremely critical. One SSME logistics challenge is documenting the assembly and disassembly of the complex joint configurations. This data (joint nomenclature, seal and fastener identification and orientation, assembly sequence, fastener torques, etc.) must be available to technicians and engineers during processing. Various assembly drawings and procedures contain this information, but in this format the required (practical) joint data can be hard to find, due to the continued use of archaic engineering drawings and microfilm for field site use. Additionally, the release system must traverse 2,500 miles between design center and field site, across three time zones, which adds communication challenges and time lags for critical engine configuration data. To aid in information accessibility, a Joint Data List (JDL) was developed that allows efficient access to practical joint data. The published JDL has been a very useful logistics product, providing illustrations and information on the latest SSME configuration. The JDL identifies over 3,350 unique parts across seven fluid systems, over 300 joints, times two distinct engine configurations. The JDL system was recently converted to a web-based, navigable

  4. Space Shuttle Main Engine Joint Data List Applying Today's Desktop Technologies to Facilitate Engine Processing

    NASA Technical Reports Server (NTRS)

    Jacobs, Kenneth; Drobnick, John; Krell, Don; Neuhart, Terry; McCool, A. (Technical Monitor)

    2001-01-01

    Boeing-Rocketdyne's Space Shuttle Main Engine (SSME) is the world's first large reusable liquid rocket engine. The space shuttle propulsion system has three SSMEs, each weighing 7,400 lbs and providing 470,000 lbs of thrust at 100% rated power level. To ensure required safety and reliability levels are achieved with the reusable engines, each SSME is partially disassembled, inspected, reassembled, and retested at Kennedy Space Center between each flight. Maintenance processing must be performed very carefully to replace any suspect components, maintain proper engine configuration, and avoid introduction of contaminants that could affect performance and safety. The long service life, and number, complexity, and pedigree of SSME components makes logistics functions extremely critical. One SSME logistics challenge is documenting the assembly and disassembly of the complex joint configurations. This data (joint nomenclature, seal and fastener identification and orientation, assembly sequence, fastener torques, etc.) must be available to technicians and engineers during processing. Various assembly drawings and procedures contain this information, but in this format the required (practical) joint data can be hard to find, due to the continued use of archaic engineering drawings and microfilm for field site use. Additionally, the release system must traverse 2,500 miles between design center and field site, across three time zones, which adds communication challenges and time lags for critical engine configuration data. To aid in information accessibility, a Joint Data List (JDL) was developed that allows efficient access to practical joint data. The published JDL has been a very useful logistics product, providing illustrations and information on the latest SSME configuration. The JDL identifies over 3,350 unique parts across seven fluid systems, over 300 joints, times two distinct engine configurations. The JDL system was recently converted to a web-based, navigable

  5. [Generally accepted engineering standards and Legionella in drinking water : findings from Frankfurt am Main].

    PubMed

    Hentschel, W; Heudorf, U

    2011-06-01

    To investigate the association between the engineering standards of drinking water systems and the extent of the Legionella colonization, we subjected our 2006 published data of the drinking water monitoring of the city's public health services for Frankfurt on Main, Germany, to closer analysis. A total of 413 records were available, with both technical data and results of the Legionella colonization. When comparing the classes of technical deficiencies of the drinking water installations with the Legionella colonization results, 93% of the Legionella data "not dedectable in 100 ml" were found in the group of drinking water installations that were technically assessed as "free of deficiencies". Thus, "good" technical engineering is associated with low or lack of Legionella colonization with a high probability even with hints for a dose-effect phenomenon-the more engineering deficiencies that exist, the higher the Legionella contamination.

  6. Space Shuttle Main Engine: Part Number RS007001

    NASA Technical Reports Server (NTRS)

    Guinzburg, A.

    1977-01-01

    Topics considered include: low-pressure oxidizer turbopump; low-pressure fuel turbopump; high-pressure oxidizer turbopump; high-pressure oxidizer turbopump turbine; high-pressure fuel turbopump; and SSME propellant flow schematic.

  7. Understanding High School Graduation Rates in Maine

    ERIC Educational Resources Information Center

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  8. Emissions from main propulsion engine on container ship at sea

    NASA Astrophysics Data System (ADS)

    Agrawal, Harshit; Welch, William A.; Henningsen, Svend; Miller, J. Wayne; Cocker, David R.

    2010-12-01

    Emission measurements were made for major gases and PM2.5 mass for a post PanaMax Class container vessel operating on heavy fuel oil at sea. Additional measurements were made for PM composition, elemental and organic carbon, select hydrocarbons, including PAHs, carbonyls, and n-alkanes. The testing followed the International Standard Organization protocols for emission measurements and operating test cycle. Results showed the weighted emission factor for NOx and PM2.5 were 19.77 ± 0.28 and 2.40 ± 0.05 g/kWh, respectively. The study provided a rare opportunity to repeat measurements made three years earlier on the same vessel. Emission factors of CO2 and NOx closely matched the earlier values, suggesting a low deterioration factor. Results showed the black carbon emission factor was 0.007 ± 0.001 g/kWh, an important metric for determining the radiative forcing contribution of marine engines.

  9. High temperature turbine engine structure

    DOEpatents

    Carruthers, William D.; Boyd, Gary L.

    1993-01-01

    A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

  10. High temperature turbine engine structure

    DOEpatents

    Carruthers, William D.; Boyd, Gary L.

    1992-01-01

    A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

  11. High temperature turbine engine structure

    DOEpatents

    Carruthers, William D.; Boyd, Gary L.

    1994-01-01

    A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

  12. Combustion Device Failures During Space Shuttle Main Engine Development

    NASA Technical Reports Server (NTRS)

    Goetz, Otto K.; Monk, Jan C.

    2005-01-01

    Major Causes: Limited Initial Materials Properties. Limited Structural Models - especially fatigue. Limited Thermal Models. Limited Aerodynamic Models. Human Errors. Limited Component Test. High Pressure. Complicated Control.

  13. Space Shuttle Main Engine Off-Nominal Low Power Level Operation

    NASA Technical Reports Server (NTRS)

    Bradley, Michael

    1997-01-01

    This paper describes Rocketdyne's successful analysis and demonstration of the Space Shuttle Main Engine (SSME) operation at off-nominal power levels during Reusable Launch Vehicle (RLV) evaluation tests. The nominal power level range for the SSME is from 65% rated power level (RPL) to 109% RPL. Off-nominal power levels incrementally demonstrated were: 17% RPL, 22% RPL, 27% RPL, 40% RPL, 45% RPL, and 50% RPL. Additional achievements during low power operation included: use of a hydrostatic bearing High Pressure Oxidizer Turbopump (HPOTP), nominal High Pressure Fuel Turbopump (HPFTP) first rotor critical speed operation, combustion stability at low power levels, and refined definition of nozzle flow separation heat loads.

  14. Space shuttle main engine anomaly data and inductive knowledge based systems: Automated corporate expertise

    NASA Technical Reports Server (NTRS)

    Modesitt, Kenneth L.

    1987-01-01

    Progress is reported on the development of SCOTTY, an expert knowledge-based system to automate the analysis procedure following test firings of the Space Shuttle Main Engine (SSME). The integration of a large-scale relational data base system, a computer graphics interface for experts and end-user engineers, potential extension of the system to flight engines, application of the system for training of newly-hired engineers, technology transfer to other engines, and the essential qualities of good software engineering practices for building expert knowledge-based systems are among the topics discussed.

  15. Test Results of the Modified Space Shuttle Main Engine at the Marshall Space Flight Center Technology Test Bed Facility

    NASA Technical Reports Server (NTRS)

    Cook, J.; Dumbacher, D.; Ise, M.; Singer, C.

    1990-01-01

    A modified space shuttle main engine (SSME), which primarily includes an enlarged throat main combustion chamber with the acoustic cavities removed and a main injector with the stability control baffles removed, was tested. This one-of-a-kind engine's design changes are being evaluated for potential incorporation in the shuttle flight program in the mid-1990's. Engine testing was initiated on September 15, 1988 and has accumulated 1,915 seconds and 19 starts. Testing is being conducted to characterize the engine system performance, combustion stability with the baffle-less injector, and both low pressure oxidizer turbopump (LPOTP) and high pressure oxidizer turbopump (HPOTP) for suction performance. These test results are summarized and compared with the SSME flight configuration data base. Testing of this new generation SSME is the first product from the technology test bed (TTB). Figure test plans for the TTB include the highly instrumented flight configuration SSME and advanced liquid propulsion technology items.

  16. Airflow Model Testing to Determine the Distribution of Hot Gas Flow and O/F Ratio Across the Space Shuttle Main Engine Main Injector Assembly

    NASA Technical Reports Server (NTRS)

    Mahorter, L.; Chik, J.; McDaniels, D.; Dill, C.

    1990-01-01

    Engine 0209, the certification engine for the new Phase 2+ Hot Gas Manifold (HGM), showed severe deterioration of the Main Combustion Chamber (MCC) liner during hot fire tests. One theory on the cause of the damage held that uneven local distribution of the fuel rich hot gas flow through the main injector assembly was producing regions of high oxidizer/fuel (O/F) ratio near the wall of the MCC liner. Airflow testing was proposed to measure the local hot gas flow rates through individual injector elements. The airflow tests were conducted using full scale, geometrically correct models of both the current Phase 2 and the new Phase 2+ HGMs. Different main injector flow shield configurations were tested for each HGM to ascertain their effect on the pressure levels and distribution of hot gas flow. Instrumentation located on the primary faceplate of the main injector measured hot gas flow through selected injector elements. These data were combined with information from the current space shuttle main engine (SSME) power balances to produce maps of pressure, hot gas flow rate, and O/F ratio near the main injector primary plate. The O/F distributions were compared for the different injector and HGM configurations.

  17. Low loss injector for Space Shuttle main engine. Center director's discretionary fund

    NASA Technical Reports Server (NTRS)

    Vonpragenau, G. L.

    1984-01-01

    An efficient propellant injection method to raise the Space Shuttle Main Engine (SSME) thrust and payload is discussed. Relatively large diameter injector elements with low pressure loss are recommended for the main combustion chamber and the pre-burners. Smaller losses admit more propellant flow which then raises thrust. Payload is not only gained by specific impulse but also by thrust. The chamber pressure is stabilized by selecting the proper cavity size for the injector elements while reducing the injection pressure loss which normally is kept high for stability. The rather large injector element recesses provide acoustic damping which makes baffles and acoustic absorbers unnecessary. A tenfold reduction of flow induced stresses which are rather high in the present design is shown. Relaxed tolerances, fewer elements, and better maintenance are offered. The study was conducted under a center director discretionary fund assignment.

  18. Steady-state analysis of a nonlinear rotor-housing system. [Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Noah, S. T.; Kim, Y. B.

    1990-01-01

    The periodic steady state response of a high pressure oxygen turbopump (HBOTP) of a Space Shuttle main engine (SSME), involving a clearance between the bearing and housing carrier, is sought. A harmonic balance method utilizig Fast Fourier Transform (FFT) algorithm is developed for the analysis. An impedance method is used to reduce the number of degrees of freedom to the displacements at the bearing clearance. Harmonic and subharmonic responses to imbalance for various system parameters are studied. The results show that the computational technique developed in this study is an effective and flexible method for determining the stable and unstable periodic response of complex rotor-housing systems with clearance type nonlinearity.

  19. Enabling High Efficiency Ethanol Engines

    SciTech Connect

    Szybist, J.; Confer, K.

    2011-03-01

    Delphi Automotive Systems and ORNL established this CRADA to explore the potential to improve the energy efficiency of spark-ignited engines operating on ethanol-gasoline blends. By taking advantage of the fuel properties of ethanol, such as high compression ratio and high latent heat of vaporization, it is possible to increase efficiency with ethanol blends. Increasing the efficiency with ethanol-containing blends aims to remove a market barrier of reduced fuel economy with E85 fuel blends, which is currently about 30% lower than with petroleum-derived gasoline. The same or higher engine efficiency is achieved with E85, and the reduction in fuel economy is due to the lower energy density of E85. By making ethanol-blends more efficient, the fuel economy gap between gasoline and E85 can be reduced. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has extensive knowledge and experience in powertrain components and subsystems as well as overcoming real-world implementation barriers. ORNL has extensive knowledge and expertise in non-traditional fuels and improving engine system efficiency for the next generation of internal combustion engines. Partnering to combine these knowledge bases was essential towards making progress to reducing the fuel economy gap between gasoline and E85. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, usually on a bi-weekly basis, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided substantial hardware support to the project by providing components for the single-cylinder engine experiments, engineering support for hardware modifications, guidance for operational strategies on engine research, and hardware support by providing a flexible multi-cylinder engine to be used for optimizing engine efficiency with ethanol-containing fuels.

  20. High Stability Engine Control (HISTEC)

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Southwick, Robert D.; Gallops, George W.

    1996-01-01

    Future aircraft turbine engines, both commercial and military, must be able to successfully accommodate expected increased levels of steady-state and dynamic engine-face distortion. The current approach of incorporating a sufficient component design stall margin to tolerate these increased levels of distortion would significantly reduce performance. The objective of the High Stability Engine Control (HISTEC) program is to design, develop, and flight demonstrate an advanced, high-stability, integrated engine control system that uses measurement-based, real-time estimates of distortion to enhance engine stability. The resulting distortion tolerant control reduces the required design stall margin, with a corresponding increase in performance and decrease in fuel burn. The HISTEC concept, consisting of a Distortion Estimation System and a Stability Management Control, has been designed and developed. The Distortion Estimation System uses a small number of high-response pressure sensors at the engine face to calculate indicators of the type and extent of distortion in real time. The Stability Management Control, through direct control of the fan and compressor pressure ratio, accommodates the distortion by transiently increasing the amount of stall margin available based on information from the Distortion Estimation System. Simulation studies have shown the HISTEC distortion tolerant control is able to successfully estimate and accommodate time-varying distortion. Currently, hardware and software systems necessary for flight demonstration of the HISTEC concept are being designed and developed. The HISTEC concept will be flight tested in early 1997.

  1. History of Space Shuttle Main Engine Turbopump Bearing Testing at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Gibson, Howard; Thom, Robert; Moore, Chip; Haluck, Dave

    2010-01-01

    The Space Shuttle is propelled into orbit by two solid rocket motors and three liquid fed main engines. After the solid motors fall away, the shuttle engines continue to run for a total time of 8 minutes. These engines are fed propellants by low and high pressure turbopumps. A critical part of the turbopump is the main shaft that supports the drive turbine and the pump inducer and impeller. Rolling element bearings hold the shaft in place during rotation. If the bearings were to fail, the shaft would move, allowing components to rub in a liquid oxygen or hydrogen environment, which could have catastrophic results. These bearings are required to spin at very high speeds, support radial and axial loads, and have high wear resistance without the benefit of a conventional means of lubrication. The Rocketdyne built Shuttle turbopumps demonstrated their capability to perform during launches; however, the seven hour life requirement was not being met. One of the limiting factors was the bearings. In the late 1970's, an engineering team was formed at the Marshall Space Flight Center (MSFC), to develop a test rig and plan for testing the Shuttle s main engine high pressure oxygen turbopump (HPOTP) bearings. The goals of the program were to better understand the operation of bearings in a cryogenic environment and to further develop and refine existing computer models used to predict the operational limits of these bearings. In 1982, testing began in a rig named the Bearing and Seal Material Tester or BSMT as it was commonly called. The first testing investigated the thermal margin and thermal runaway limits of the HPOTP bearings. The test rig was later used to explore potential bearing improvements in the area of increased race curvatures, new cage materials for better lubrication, new wear resistant rolling element materials, and other ideas to improve wear life. The most notable improvements during this tester s time was the incorporation of silicon nitride balls and

  2. Advanced Vacuum Plasma Spray (VPS) for a Robust, Longlife and Safe Space Shuttle Main Engine (SSME)

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Elam, Sandra K.; McKechnie, Timothy N.; Power, Christopher A.

    2010-01-01

    In 1984, the Vacuum Plasma Spray Lab was built at NASA/Marshall Space Flight Center for applying durable, protective coatings to turbine blades for the space shuttle main engine (SSME) high pressure fuel turbopump. Existing turbine blades were cracking and breaking off after five hot fire tests while VPS coated turbine blades showed no wear or cracking after 40 hot fire tests. Following that, a major manufacturing problem of copper coatings peeling off the SSME Titanium Main Fuel Valve Housing was corrected with a tenacious VPS copper coating. A patented VPS process utilizing Functional Gradient Material (FGM) application was developed to build ceramic lined metallic cartridges for space furnace experiments, safely containing gallium arsenide at 1260 degrees centigrade. The VPS/FGM process was then translated to build robust, long life, liquid rocket combustion chambers for the space shuttle main engine. A 5K (5,000 Lb. thrust) thruster with the VPS/FGM protective coating experienced 220 hot firing tests in pristine condition with no wear compared to the SSME which showed blanching (surface pulverization) and cooling channel cracks in less than 30 of the same hot firing tests. After 35 of the hot firing tests, the injector face plates disintegrated. The VPS/FGM process was then applied to spraying protective thermal barrier coatings on the face plates which showed 50% cooler operating temperature, with no wear after 50 hot fire tests. Cooling channels were closed out in two weeks, compared to one year for the SSME. Working up the TRL (Technology Readiness Level) to establish the VPS/FGM process as viable technology, a 40K thruster was built and is currently being tested. Proposed is to build a J-2X size liquid rocket engine as the final step in establishing the VPS/FGM process TRL for space flight.

  3. Advanced Vacuum Plasma Spray (VPS) for a Robust, Longlife and Safe Space Shuttle Main Engine (SSME)

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Elam, Sandra K.; McKechnie, Timothy N.; Power, Christopher A.

    2010-01-01

    In 1984, the Vacuum Plasma Spray Lab was built at NASA/Marshall Space Flight Center for applying durable, protective coatings to turbine blades for the space shuttle main engine (SSME) high pressure fuel turbopump. Existing turbine blades were cracking and breaking off after five hot fire tests while VPS coated turbine blades showed no wear or cracking after 40 hot fire tests. Following that, a major manufacturing problem of copper coatings peeling off the SSME Titanium Main Fuel Valve Housing was corrected with a tenacious VPS copper coating. A patented VPS process utilizing Functional Gradient Material (FGM) application was developed to build ceramic lined metallic cartridges for space furnace experiments, safely containing gallium arsenide at 1260 degrees centigrade. The VPS/FGM process was then translated to build robust, long life, liquid rocket combustion chambers for the space shuttle main engine. A 5K (5,000 Lb. thrust) thruster with the VPS/FGM protective coating experienced 220 hot firing tests in pristine condition with no wear compared to the SSME which showed blanching (surface pulverization) and cooling channel cracks in less than 30 of the same hot firing tests. After 35 of the hot firing tests, the injector face plates disintegrated. The VPS/FGM process was then applied to spraying protective thermal barrier coatings on the face plates which showed 50% cooler operating temperature, with no wear after 50 hot fire tests. Cooling channels were closed out in two weeks, compared to one year for the SSME. Working up the TRL (Technology Readiness Level) to establish the VPS/FGM process as viable technology, a 40K thruster was built and is currently being tested. Proposed is to build a J-2X size liquid rocket engine as the final step in establishing the VPS/FGM process TRL for space flight.

  4. On-line implementation of nonlinear parameter estimation for the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Buckland, Julia H.; Musgrave, Jeffrey L.; Walker, Bruce K.

    1992-01-01

    We investigate the performance of a nonlinear estimation scheme applied to the estimation of several parameters in a performance model of the Space Shuttle Main Engine. The nonlinear estimator is based upon the extended Kalman filter which has been augmented to provide estimates of several key performance variables. The estimated parameters are directly related to the efficiency of both the low pressure and high pressure fuel turbopumps. Decreases in the parameter estimates may be interpreted as degradations in turbine and/or pump efficiencies which can be useful measures for an online health monitoring algorithm. This paper extends previous work which has focused on off-line parameter estimation by investigating the filter's on-line potential from a computational standpoint. ln addition, we examine the robustness of the algorithm to unmodeled dynamics. The filter uses a reduced-order model of the engine that includes only fuel-side dynamics. The on-line results produced during this study are comparable to off-line results generated previously. The results show that the parameter estimates are sensitive to dynamics not included in the filter model. Off-line results using an extended Kalman filter with a full order engine model to address the robustness problems of the reduced-order model are also presented.

  5. High School Teachers' Conceptions of Engineers and Engineering

    ERIC Educational Resources Information Center

    Hoh, Yin Kiong

    2012-01-01

    This paper describes a workshop activity the author has carried out with 80 high school science teachers to enable them to overcome their stereotypical perceptions of engineers and engineering. The activity introduced them to the biographies of prominent women in engineering, and raised their awareness of these female engineers' contributions to…

  6. Leak Location and Classification in the Space Shuttle Main Engine Nozzle by Infrared Testing

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.; Walker, James L.; Lansing, Mathew

    2003-01-01

    The Space Shuttle Main Engine (SSME) is composed of cooling tubes brazed to the inside of a conical structural jacket. Because of the geometry there are regions that can't be inspected for leaks using the bubble solution and low-pressure method. The temperature change due escaping gas is detectable on the surface of the nozzle under the correct conditions. The methods and results presented in this summary address the thermographic identification of leaks in the Space Shuttle Main Engine nozzles. A highly sensitive digital infrared camera is used to record the minute temperature change associated with a leak source, such as a crack or pinhole, hidden within the nozzle wall by observing the inner "hot wall" surface as the nozzle is pressurized. These images are enhanced by digitally subtracting a thermal reference image taken before pressurization, greatly diminishing background noise. The method provides a nonintrusive way of localizing the tube that is leaking and the exact leak source position to within a very small axial distance. Many of the factors that influence the inspectability of the nozzle are addressed; including pressure rate, peak pressure, gas type, ambient temperature and surface preparation.

  7. Leak Location and Classification in the Space Shuttle Main Engine Nozzle by Infrared Testing

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.; Walker, James L.; Lansing, Mathew

    2003-01-01

    The Space Shuttle Main Engine (SSME) is composed of cooling tubes brazed to the inside of a conical structural jacket. Because of the geometry there are regions that can't be inspected for leaks using the bubble solution and low-pressure method. The temperature change due escaping gas is detectable on the surface of the nozzle under the correct conditions. The methods and results presented in this summary address the thermographic identification of leaks in the Space Shuttle Main Engine nozzles. A highly sensitive digital infrared camera is used to record the minute temperature change associated with a leak source, such as a crack or pinhole, hidden within the nozzle wall by observing the inner "hot wall" surface as the nozzle is pressurized. These images are enhanced by digitally subtracting a thermal reference image taken before pressurization, greatly diminishing background noise. The method provides a nonintrusive way of localizing the tube that is leaking and the exact leak source position to within a very small axial distance. Many of the factors that influence the inspectability of the nozzle are addressed; including pressure rate, peak pressure, gas type, ambient temperature and surface preparation.

  8. Real-time control for manufacturing space shuttle main engines: Work in progress

    NASA Technical Reports Server (NTRS)

    Ruokangas, Corinne C.

    1988-01-01

    During the manufacture of space-based assemblies such as Space Shuttle Main Engines, flexibility is required due to the high-cost and low-volume nature of the end products. Various systems have been developed pursuing the goal of adaptive, flexible manufacturing for several space applications, including an Advanced Robotic Welding System for the manufacture of complex components of the Space Shuttle Main Engines. The Advanced Robotic Welding System (AROWS) is an on-going joint effort, funded by NASA, between NASA/Marshall Space Flight Center, and two divisions of Rockwell International: Rocketdyne and the Science Center. AROWS includes two levels of flexible control of both motion and process parameters: Off-line programming using both geometric and weld-process data bases, and real-time control incorporating multiple sensors during weld execution. Both control systems were implemented using conventional hardware and software architectures. The feasibility of enhancing the real-time control system using the problem-solving architecture of Schemer is investigated and described.

  9. High temperature turbine engine structure

    DOEpatents

    Boyd, Gary L.

    1990-01-01

    A high temperature turbine engine includes a hybrid ceramic/metallic rotor member having ceramic/metal joint structure. The disclosed joint is able to endure higher temperatures than previously possible, and aids in controlling heat transfer in the rotor member.

  10. High temperature turbine engine structure

    DOEpatents

    Boyd, Gary L.

    1991-01-01

    A high temperature turbine engine includes a rotor portion having axially stacked adjacent ceramic rotor parts. A ceramic/ceramic joint structure transmits torque between the rotor parts while maintaining coaxial alignment and axially spaced mutually parallel relation thereof despite thermal and centrifugal cycling.

  11. Configuration evaluation and criteria plan. Volume 2: Evaluation criteria plan (update). Space Transportation Main Engine (STME) configuration study

    NASA Technical Reports Server (NTRS)

    Bair, E. K.

    1987-01-01

    Candidate main engine configurations which enhance vehicle performance, operation and cost are identified. These candidate configurations are evaluated and the configurations which provide significant advantages over existing systems are selected for consideration for the next generation of launch vehicles. The unbiased selection of the Space Transportation Main Engine (STME) configuration requires that the candidate engines be evaluated against a predetermined set of criteria which must be properly weighted to emphasize critical requirements defined prior to the actual evaluation. During a prior study of the STME a Gas Generator Cycle engine was selected for conceptual design, with emphasis on reusability, reliability and low cost while achieving good performance. In this study emphasis is on expendable application of the STME while maintaining low cost and high reliability.

  12. Emissions of NOx, particle mass and particle numbers from aircraft main engines, APU's and handling equipment at Copenhagen Airport

    NASA Astrophysics Data System (ADS)

    Winther, Morten; Kousgaard, Uffe; Ellermann, Thomas; Massling, Andreas; Nøjgaard, Jacob Klenø; Ketzel, Matthias

    2015-01-01

    This paper presents a detailed emission inventory for NOx, particle mass (PM) and particle numbers (PN) for aircraft main engines, APU's and handling equipment at Copenhagen Airport (CPH) based on time specific activity data and representative emission factors for the airport. The inventory has a high spatial resolution of 5 m × 5 m in order to be suited for further air quality dispersion calculations. Results are shown for the entire airport and for a section of the airport apron area ("inner apron") in focus. The methodology presented in this paper can be used to quantify the emissions from aircraft main engines, APU and handling equipment in other airports. For the entire airport, aircraft main engines is the largest source of fuel consumption (93%), NOx, (87%), PM (61%) and PN (95%). The calculated fuel consumption [NOx, PM, PN] shares for APU's and handling equipment are 5% [4%, 8%, 5%] and 2% [9%, 31%, 0%], respectively. At the inner apron area for handling equipment the share of fuel consumption [NOx, PM, PN] are 24% [63%, 75%, 2%], whereas APU and main engines shares are 43% [25%, 19%, 54%], and 33% [11%, 6%, 43%], respectively. The inner apron NOx and PM emission levels are high for handling equipment due to high emission factors for the diesel fuelled handling equipment and small for aircraft main engines due to small idle-power emission factors. Handling equipment is however a small PN source due to the low number based emission factors. Jet fuel sulphur-PM sensitivity calculations made in this study with the ICAO FOA3.0 method suggest that more than half of the PM emissions from aircraft main engines at CPH originate from the sulphur content of the fuel used at the airport. Aircraft main engine PN emissions are very sensitive to the underlying assumptions. Replacing this study's literature based average emission factors with "high" and "low" emission factors from the literature, the aircraft main engine PN emissions were estimated to change with a

  13. Detection, Location, and Classification of Space Shuttle Main Engine Nozzle Leaks by Transient Thermographic Inspection

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.; Walker, James L.

    1998-01-01

    Leak checking and evaluation of pressure vessels by observing the slight temperature changes resulting from structural anomalies has been made possible through developments in high resolution infrared cameras and advanced image processing. These developments have made thermal nondestructive analysis a very practical and efficient method to determine material consistency and structural quality as well as monitor processes. The Space Shuttle Main Engine Nozzle has regions which can not be inspected with standard leak check methods. The Thermographic methods being developed to nondestructively test the Nozzle for leaks in inaccessible regions are reported. Also, a flash heating Thermographic investigation of the braze line bonding the cooling tubes to the outer structural jacket of the nozzle is reported.

  14. Thermographic/Nondestructive Evaluation of the Space Shuttle Main Engine Nozzle

    NASA Technical Reports Server (NTRS)

    Walker, J. L.; Russell, S. S.; Lansing, M. D.; Caraccioli, P.

    2001-01-01

    The methods and results presented in this summary address the thermographic identification of interstitial leaks in the Space Shuttle Main Engine nozzles. A highly sensitive digital infrared camera is used to record the minute cooling effects associated with a leak source, such as a crack or pinhole, hidden within the nozzle wall by observing the inner 'hot wall' surface as the nozzle is pressurized. These images are enhanced by digitally subtracting a thermal reference image taken before pressurization, greatly diminishing background noise. The method provides a nonintrusive way of localizing the tube that is leaking and the exact leak source position to within a very small axial distance. Many of the factors that influence the inspectability of the nozzle are addressed; including pressure rate, peak pressure, gas type, ambient temperature and surface preparation.

  15. Prediction of the Main Engine Power of a New Container Ship at the Preliminary Design Stage

    NASA Astrophysics Data System (ADS)

    Cepowski, Tomasz

    2017-06-01

    The paper presents mathematical relationships that allow us to forecast the estimated main engine power of new container ships, based on data concerning vessels built in 2005-2015. The presented approximations allow us to estimate the engine power based on the length between perpendiculars and the number of containers the ship will carry. The approximations were developed using simple linear regression and multivariate linear regression analysis. The presented relations have practical application for estimation of container ship engine power needed in preliminary parametric design of the ship. It follows from the above that the use of multiple linear regression to predict the main engine power of a container ship brings more accurate solutions than simple linear regression.

  16. Thermal Analysis on Plume Heating of the Main Engine on the Crew Exploration Vehicle Service Module

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Yuko, James R.

    2007-01-01

    The crew exploration vehicle (CEV) service module (SM) main engine plume heating is analyzed using multiple numerical tools. The chemical equilibrium compositions and applications (CEA) code is used to compute the flow field inside the engine nozzle. The plume expansion into ambient atmosphere is simulated using an axisymmetric space-time conservation element and solution element (CE/SE) Euler code, a computational fluid dynamics (CFD) software. The thermal analysis including both convection and radiation heat transfers from the hot gas inside the engine nozzle and gas radiation from the plume is performed using Thermal Desktop. Three SM configurations, Lockheed Martin (LM) designed 604, 605, and 606 configurations, are considered. Design of multilayer insulation (MLI) for the stowed solar arrays, which is subject to plume heating from the main engine, among the passive thermal control system (PTCS), are proposed and validated.

  17. Public views evening engine test of a Space Shuttle Main Engine

    NASA Image and Video Library

    2001-04-21

    Over the past year, more than 20,000 people came to Stennis Space Center to witness the 'shake, rattle and roar' of one of the world's most sophisticated engines. Stennis Space Center in south Mississippi is NASA's lead center for rocket propulsion testing. StenniSphere, the visitor center for Stennis Space Center, hosted more than 250,000 visitors in its first year of operation. Of those visitors, 26.4 percent were from Louisiana.

  18. Parametric Engineering System Definition Model. Volume I. Main Report. Appendices A and B

    DTIC Science & Technology

    1979-08-01

    B.1O AMMUNITION STORAGE TOTAL CAPACITY, MAIN GUN ROUNDER C. POWER TRAIN C.1 ENGINE TYPE (1-DIESEL; 2- TURBINE ; 3-SPARK, RECIPROCATING 4-ROTARY...WIDTH HEIGHT * CLEARANCE TO REAR DECK CLEARANCE TO SIDEWALL C.2 TRANSMISSION TYPE (1-MANUAL; 2- HYDROKINETIC ; 3-HYDROMECHANICAL) * EFFICIENCY (HP...Power Train Elements in the Hull of the Conventional Tank Figure 65 (e. g., a diesel engine, a turbine , etc.) and the horsepower requirements

  19. Understanding the Space Shuttle Main Engine Hydraulic Actuation System and Reviewing Its Evolution

    NASA Technical Reports Server (NTRS)

    McWade, Robert J.; Minor, Robert B.; McNutt, Leslie M.

    2010-01-01

    The complex engine start and thrust control requirements of the Space Shuttle Main Engine (SSME) require unique valve, actuator and control system hardware. The Hydraulic Actuation System (HAS) was designed, developed, and now operates to meet tight engine control requirement limits to assure safe, reliable and correct engine thrust at all times. The actuator is designed to be fail safe and fail operate in the areas where redundancy is important. The HAS has an additional pneumatic operating capability that insures a safe sequential closure of all actuators and propellant valves in the event of the loss of hydraulic system pressure or loss of electrical closed loop control of the actuator. The objective of this paper is to provide a complete description of the actuator s internal operating system, along with its interaction with all SSME system interfaces. Additionally the paper addresses the challenges, problems identified, and corrected, and lessons learned, during the course of the almost 35 years of engine operation.

  20. Understanding the Space Shuttle Main Engine Hydraulic Actuation System and Reviewing Its Evolution

    NASA Technical Reports Server (NTRS)

    McWade, Robert J.; Minor, Robert B.; McNutt, Leslie M.

    2010-01-01

    The complex engine start and thrust control requirements of the Space Shuttle Main Engine (SSME) require unique valve, actuator and control system hardware. The Hydraulic Actuation System (HAS) was designed, developed, and now operates to meet tight engine control requirement limits to assure safe, reliable and correct engine thrust at all times. The actuator is designed to be fail safe and fail operate in the areas where redundancy is important. The HAS has an additional pneumatic operating capability that insures a safe sequential closure of all actuators and propellant valves in the event of the loss of hydraulic system pressure or loss of electrical closed loop control of the actuator. The objective of this paper is to provide a complete description of the actuator s internal operating system, along with its interaction with all SSME system interfaces. Additionally the paper addresses the challenges, problems identified, and corrected, and lessons learned, during the course of the almost 35 years of engine operation.

  1. Thermal barrier coatings for the space shuttle main engine turbine blades

    NASA Technical Reports Server (NTRS)

    Bhat, B. N.; Gilmore, H. L.; Holmes, R. R.

    1985-01-01

    The Space Shuttle Main Engine (SSME) turbopump turbine blades experience extremely severe thermal shocks during start-up and shut-down. For instance, the high pressure fuel turbopump turbine which burns liquid hydrogen operates at approximately 1500 F, but is shut down fuel rich with turbine blades quenced in liquid hydrogen. This thermal shock is a major contributor to blade cracking. The same thermal shock cause the protective ZrO2 thermal barrier coatings to spall or flake off, leaving only the NiCrAlY bond coating which provides only a minimum thermal protection. The turbine blades are therefore life limited to about 3000 sec for want of a good thermal barrier. A suitable thermal barrier coating (TBC) is being developed for the SSME turbine blades. Various TBCs developed for the gas turbine engines were tested in a specially built turbine blade tester. This tester subjects the coated blades to thermal and pressure cycles similar to those during actual operation of the turbine. The coatings were applied using a plasma spraying techniques both under atmospheric conditions and in vacuum. Results are presented. In general vacuum plasma sprayed coatings performed much better than those sprayed under atmospheric conditions. A 50 to 50 blend of Cr2O3 and NiCrAlY, vacuum plasma sprayed on SSME turbopump turbine blades appear to provide significant improvements in coating durability and thermal protection.

  2. The Development of Titanium Alloys for Application in the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Halchak, John A.; Jerman, Gregory A.; Zimmerman, Frank R.

    2010-01-01

    The high-strength-to-weight ratio of titanium alloys, particularly at cryogenic temperatures, make them attractive for application in rocket engines - offering the potential of superior performance while minimizing component weight. This was particularly attractive for rotating components, such as pump impellers, where titanium alloys presented the potential to achieve a major advance in rotational tip speed, with a reduction in stages and resultant saving in pump weight and complexity. The investigation into titanium alloys for application in cryogenic turbopumps began in the early 1960's. However, it was found that the reactivity of titanium limited applications and produced unique processing challenges. Specialized chemical compositions and processing techniques had to be developed. A substantial amount of material properties testing and trials in experimental turbopumps occurred, ultimately leading to application in the Space Shuttle Main Engine. One particular alloy stood out for use at liquid hydrogen temperatures, Ti-5Al-2.5Sn ELI. This alloy was employed for several critical components. This presentation deals with the development effort, the challenges that were encountered and operational experiences with Ti-5Al-2.5Sn ELI in the SSME.

  3. The Development of Titanium Alloys for Application in the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Halchak, John A.; Jerman, Gregory A.; Zimmerman, Frank R.

    2010-01-01

    The high-strength-to-weight ratio of titanium alloys, particularly at cryogenic temperatures, make them attractive for application in rocket engines - offering the potential of superior performance while minimizing component weight. This was particularly attractive for rotating components, such as pump impellers, where titanium alloys presented the potential to achieve a major advance in rotational tip speed, with a reduction in stages and resultant saving in pump weight and complexity. The investigation into titanium alloys for application in cryogenic turbopumps began in the early 1960's. However, it was found that the reactivity of titanium limited applications and produced unique processing challenges. Specialized chemical compositions and processing techniques had to be developed. A substantial amount of material properties testing and trials in experimental turbopumps occurred, ultimately leading to application in the Space Shuttle Main Engine. One particular alloy stood out for use at liquid hydrogen temperatures, Ti-5Al-2.5Sn ELI. This alloy was employed for several critical components. This presentation deals with the development effort, the challenges that were encountered and operational experiences with Ti-5Al-2.5Sn ELI in the SSME.

  4. Sloshing in the Liquid Hydrogen and Liquid Oxygen Propellant Tanks After Main Engine Cut Off

    NASA Technical Reports Server (NTRS)

    Kim, Sura; West, Jeff

    2011-01-01

    NASA Marshall Space Flight Center is designing and developing the Main Propulsion System (MPS) for Ares launch vehicles. Propellant sloshing in the liquid hydrogen (LH2) and liquid oxygen (LO2) propellant tanks after Main Engine Cut Off (MECO) was modeled using the Volume of Fluid (VOF) module of the computational fluid dynamics code, CFD-ACE+. The present simulation shows that there is substantial sloshing side forces acting on the LH2 tank during the deceleration of the vehicle after MECO. The LH2 tank features a side wall drain pipe. The side loads result from the residual propellant mass motion in the LH2 tank which is initiated by the stop of flow into the drain pipe at MECO. The simulations show that radial force on the LH2 tank wall is less than 50 lbf and the radial moment calculated based up through the center of gravity of the vehicle is predicted to be as high as 300 lbf-ft. The LO2 tank features a bottom dome drain system and is equipped with sloshing baffles. The remaining LO2 in the tank slowly forms a liquid column along the centerline of tank under the zero gravity environments. The radial force on the LO2 tank wall is predicted to be less than 100 lbf. The radial moment calculated based on the center of gravity of the vehicle is predicted as high as 4500 lbf-ft just before MECO and dropped down to near zero after propellant draining stopped completely.

  5. Space Shuttle Main Engine fuel preburner augmented spark igniter shutdown detonations

    NASA Technical Reports Server (NTRS)

    Dexter, C. E.; Mccay, T. D.

    1986-01-01

    Detonations were experienced in the Space Shuttle Main Engine fuel preburner (FPB) augmented spark igniter (ASI) during engine cutoff. Several of these resulted in over pressures sufficient to damage the FPB ASI oxidizer system. The detonations initiated in the FPB ASI oxidizer line when residual oxidizer (oxygen) in the line mixed with backflowing fuel (hydrogen) and detonated. This paper reviews the damage history to the FPB ASI oxidizer system, an engineering assessment of the problem cause, a verification of the mechanisms, the hazards associated with the detonations, and the solution implemented.

  6. An overview of the current technology relevant to the design and development of the Space Transportation Main Engine (STME)

    NASA Technical Reports Server (NTRS)

    Das, Digendra K.

    1991-01-01

    The objective of this project was to review the latest literature relevant to the Space Transportation Main Engine (STME). The search was focused on the following engine components: (1) gas generator; (2) hydrostatic/fluid bearings; (3) seals/clearances; (4) heat exchanges; (5) nozzles; (6) nozzle/main combustion chamber joint; (7) main injector face plate; and (8) rocket engine.

  7. Factors influencing design and selection of GTAW robotic welding machines for the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Flanigan, L.

    1986-01-01

    Proposed hardware and software for microprocessor-controlled power supplies and welding machines are described. The application of the automatic seven-axis welding machine, which is to be preprogrammed to allow minimum intervention by the welding operator during the actual process, to the welding of the Space Shuttle main engine is discussed. The production requirements for the gas tungsten arc welds for the Space Shuttle main engine are examined. Consideration is given to positioner design, welding variables, inert shielding gas management, filler metal wire control, the up loading and down loading of data from off-line computers, process improvements, tooling, the welding variable library, and adaptive sensor control.

  8. Factors influencing design and selection of GTAW robotic welding machines for the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Flanigan, L.

    1986-01-01

    Proposed hardware and software for microprocessor-controlled power supplies and welding machines are described. The application of the automatic seven-axis welding machine, which is to be preprogrammed to allow minimum intervention by the welding operator during the actual process, to the welding of the Space Shuttle main engine is discussed. The production requirements for the gas tungsten arc welds for the Space Shuttle main engine are examined. Consideration is given to positioner design, welding variables, inert shielding gas management, filler metal wire control, the up loading and down loading of data from off-line computers, process improvements, tooling, the welding variable library, and adaptive sensor control.

  9. Space shuttle main engine definition (phase B). Volume 2: Avionics. [for space shuttle

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The advent of the space shuttle engine with its requirements for high specific impulse, long life, and low cost have dictated a combustion cycle and a closed loop control system to allow the engine components to run close to operating limits. These performance requirements, combined with the necessity for low operational costs, have placed new demands on rocket engine control, system checkout, and diagnosis technology. Based on considerations of precision environment, and compatibility with vehicle interface commands, an electronic control, makes available many functions that logically provide the information required for engine system checkout and diagnosis.

  10. Main propulsion system test requirements for the two-engine Shuttle-C

    NASA Technical Reports Server (NTRS)

    Lynn, E. E.; Platt, G. K.

    1989-01-01

    The Shuttle-C is an unmanned cargo carrying derivative of the space shuttle with optional two or three space shuttle main engines (SSME's), whereas the shuttle has three SSME's. Design and operational differences between the Shuttle-C and shuttle were assessed to determine requirements for additional main propulsion system (MPS) verification testing. Also, reviews were made of the shuttle main propulsion test program objectives and test results and shuttle flight experience. It was concluded that, if significant MPS modifications are not made beyond those currently planned, then main propulsion system verification can be concluded with an on-pad flight readiness firing.

  11. Replacement of the left main bronchus with a tissue-engineered prosthesis in a canine model.

    PubMed

    Sato, Toshihiko; Tao, Hiroyuki; Araki, Masato; Ueda, Hiroki; Omori, Koichi; Nakamura, Tatsuo

    2008-08-01

    Stenosis of the left main bronchus caused by inflammatory diseases and neoplasms is a serious clinical problem because it can cause obstructive pneumonia and may require pneumonectomy. As an alternative to various treatments currently available, including balloon dilatation, stenting, and bronchoplasty, we propose the use of a prosthesis developed based on the concept of in situ tissue engineering for replacement of the left main bronchus. The main frame of the tissue-engineered prosthesis is a polypropylene mesh tube, 12 to 15 mm in inner diameter and 30 mm in length, with reinforcing rings. Collagen extracted from porcine skin is conjugated to this frame. A consecutive series of 8 beagle dogs underwent replacement of the left main bronchus with this tissue-engineered prosthesis. All dogs survived the postoperative period with no morbidity except 1, which required intravenous administration of antibiotic for a week for pneumonia and recovered. Three dogs were euthanized for examination at 3 and 4 months after bronchus replacement, and the other five were monitored for more than 1 year. In two dogs, histologic examination revealed that the luminal surface was completely covered with ciliated columnar epithelium or nonciliated squamous epithelium. Exposure of the polypropylene mesh to various degrees was observed in 6 dogs, but the prosthesis remained stable and no adverse effects such as infection, sputum retention, or dehiscence were observed. These long-term results suggest that our tissue-engineered prosthesis is applicable for replacement of the left main bronchus.

  12. Fluid mass and thermal loading effects on the modal characteristics of space shuttle main engine liquid oxygen inlet splitter vanes

    NASA Technical Reports Server (NTRS)

    Panossian, H. V.; Boehnlein, J. J.

    1987-01-01

    An analysis and evaluation of experimental modal survey test data on the variations of modal characteristics induced by pressure and thermal loading events are presented. Extensive modal survey tests were carried out on a Space Shuttle Main Engine (SSME) test article using liquid nitrogen under cryogenic temperatures and high pressures. The results suggest that an increase of pressure under constant cryogenic temperature or a decrease of temperature under high pressure induces an upward shift of frequencies of various modes of the structures.

  13. A data base and analysis program for shuttle main engine dynamic pressure measurements

    NASA Technical Reports Server (NTRS)

    Coffin, T.

    1986-01-01

    A dynamic pressure data base management system is described for measurements obtained from space shuttle main engine (SSME) hot firing tests. The data were provided in terms of engine power level and rms pressure time histories, and power spectra of the dynamic pressure measurements at selected times during each test. Test measurements and engine locations are defined along with a discussion of data acquisition and reduction procedures. A description of the data base management analysis system is provided and subroutines developed for obtaining selected measurement means, variances, ranges and other statistics of interest are discussed. A summary of pressure spectra obtained at SSME rated power level is provided for reference. Application of the singular value decomposition technique to spectrum interpolation is discussed and isoplots of interpolated spectra are presented to indicate measurement trends with engine power level. Program listings of the data base management and spectrum interpolation software are given. Appendices are included to document all data base measurements.

  14. Application of fault factor method to fault detection and diagnosis for space shuttle main engine

    NASA Astrophysics Data System (ADS)

    Cha, Jihyoung; Ha, Chulsu; Ko, Sangho; Koo, Jaye

    2016-09-01

    This paper deals with an application of the multiple linear regression algorithm to fault detection and diagnosis for the space shuttle main engine (SSME) during a steady state. In order to develop the algorithm, the energy balance equations, which balances the relation among pressure, mass flow rate and power at various locations within the SSME, are obtained. Then using the measurement data of some important parameters of the engine, fault factors which reflects the deviation of each equation from the normal state are estimated. The probable location of each fault and the levels of severity can be obtained from the estimated fault factors. This process is numerically demonstrated for the SSME at 104% Rated Propulsion Level (RPL) by using the simulated measurement data from the mathematical models of the engine. The result of the current study is particularly important considering that the recently developed reusable Liquid Rocket Engines (LREs) have staged-combustion cycles similarly to the SSME.

  15. Quiet Clean Short-haul Experimental Engine (QCSEE) main reduction gears detailed design report

    NASA Technical Reports Server (NTRS)

    Defeo, A.; Kulina, M.

    1977-01-01

    Lightweight turbine engines with geared slower speed fans are considered. The design of two similar but different gear ratio, minimum weight, epicyclic star configuration main reduction gears for the under the wing (UTW) and over the wing (OTW) engines is discussed. The UTW engine reduction gear has a ratio of 2.465:1 and a 100% power design rating of 9885 kW (13,256 hp) at 3143 rpm fan speed. The OTW engine reduction gear has a ratio of 2.062:1 and a 100% power design rating of 12813 kW (17183 hp) at 3861 rpm fan speed. Details of configuration, stresses, deflections, and lubrication are presented.

  16. Inductive knowledge acquisition experience with commercial tools for space shuttle main engine testing

    NASA Technical Reports Server (NTRS)

    Modesitt, Kenneth L.

    1990-01-01

    Since 1984, an effort has been underway at Rocketdyne, manufacturer of the Space Shuttle Main Engine (SSME), to automate much of the analysis procedure conducted after engine test firings. Previously published articles at national and international conferences have contained the context of and justification for this effort. Here, progress is reported in building the full system, including the extensions of integrating large databases with the system, known as Scotty. Inductive knowledge acquisition has proven itself to be a key factor in the success of Scotty. The combination of a powerful inductive expert system building tool (ExTran), a relational data base management system (Reliance), and software engineering principles and Computer-Assisted Software Engineering (CASE) tools makes for a practical, useful and state-of-the-art application of an expert system.

  17. Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5

    NASA Technical Reports Server (NTRS)

    Anderson, P. J.; Nussbaum, P.; Gustafson, G.

    1984-01-01

    Research concerning the development of pressure instrumentation for the space shuttle main engine is reported. The following specific topics were addressed: (1) transducer design and materials, (2) silicon piezoresistor characterization at cryogenic temperatures, (3) chip mounting characterization, and (4) frequency response optimization.

  18. Incipient failure detection of space shuttle main engine turbopump bearings using vibration envelope detection

    NASA Technical Reports Server (NTRS)

    Hopson, Charles B.

    1987-01-01

    The results of an analysis performed on seven successive Space Shuttle Main Engine (SSME) static test firings, utilizing envelope detection of external accelerometer data are discussed. The results clearly show the great potential for using envelope detection techniques in SSME incipient failure detection.

  19. Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 6

    NASA Technical Reports Server (NTRS)

    Anderson, P. J.; Johnson, R. L.

    1984-01-01

    Research concerning the utilization of silicon piezoresistive strain sensing technology for space shuttle main engine applications is reported. The following specific topics were addressed: (1) transducer design and materials, (2) silicon piezoresistor characterization at cryogenic temperatures, (3) chip mounting characterization, and (4) frequency response optimization.

  20. Alpha-canonical form representation of the open loop dynamics of the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Duyar, Almet; Eldem, Vasfi; Merrill, Walter C.; Guo, Ten-Huei

    1991-01-01

    A parameter and structure estimation technique for multivariable systems is used to obtain a state space representation of open loop dynamics of the space shuttle main engine in alpha-canonical form. The parameterization being used is both minimal and unique. The simplified linear model may be used for fault detection studies and control system design and development.

  1. Italian High-speed Airplane Engines

    NASA Technical Reports Server (NTRS)

    Bona, C F

    1940-01-01

    This paper presents an account of Italian high-speed engine designs. The tests were performed on the Fiat AS6 engine, and all components of that engine are discussed from cylinders to superchargers as well as the test set-up. The results of the bench tests are given along with the performance of the engines in various races.

  2. Space shuttle main engine sensor modeling using radial-basis-function neural networks

    NASA Astrophysics Data System (ADS)

    Wheeler, Kevin R.; Dhawan, Atam P.; Meyer, Claudia M.

    1994-11-01

    An efficient method of parameter prediction is needed for sensor validation of space shuttle main-engine (SSME) parameters during real-time safety monitoring and post-test analysis. Feedforward neural networks (FFNN) have been used to model the highly nonlinear and dynamic SSME parameters during startup. Due to several problems associated with the use of feedforward networks, radial-basis-function neural networks (RBFNN) were investigated in modeling SSME parameters. In this paper, RBFNNs are used to predict the high-pressure oxidizer turbine discharge temperature, a redlined parameter, during the startup transient. Data from SSME ground test firings were used to train and validate the RBFNNs. The performance of the RBFNN model is compared with that of a FFNN model, trained with the Quickprop learning algorithm. In comparison with the FFNN model, the RBFNN-based model was found to be more robust against variations in architecture and network parameters, and was faster to train. In addition, the performance of the RBFNN model during nominal operation and during simulated input sensor failures was found to be robust in the presence of small deviations in the input.

  3. CARS temperature measurements in the fuel preburner of the Space Shuttle main engine: A feasibility study

    NASA Technical Reports Server (NTRS)

    Beiting, E. J.; Luthe, J. C.

    1983-01-01

    This report discusses the feasibility of making temperature profile measurements in the fuel preburner of the main engine of the space shuttle (SSME) using coherent anti-Stokes Raman spectroscopy (CARS). The principal thrust of the work is to identify problems associated with making CARS measurements in high temperature gas phase hydrogen at very high pressures (approx 400 atmospheres). To this end a theoretical study was made of the characteristics of the CAR spectra of H2 as a function of temperature and pressure and the accuracy with which temperatures can be extracted from this spectra. In addition the experimental problems associated with carrying out these measurements on a SSME at NSTL were identified. A conceptual design of a CARS system suitable for this work is included. Many of the results of the calculations made in this report are plotted as a function of temperature. In the course of presenting these results, it was necessary to decide whether the number of density or the pressure should be treated as a fixed parameter.

  4. Sloshing in Liquid Hydrogen and LOX Propellant Tanks After Main Engine Cut-off

    NASA Technical Reports Server (NTRS)

    Kim, Sura

    2011-01-01

    NASA Marshall Space Flight Center is designing and developing the Main Propulsion System (MPS) for Ares launch vehicles. The objective of this study is to calculate the sloshing forces and moments in the LH2 and LO2 propellant tanks using a CFD/VOF analysis under realistic flight conditions. Propellant sloshing in the liquid hydrogen (LH2) and the liquid oxygen (LO2) propellant tanks after Main Engine Cut Off (MECO) was modeled using the Volume of Fluid (VOF) module of the computational fluid dynamics code, CFD-ACE+. The present simulation shows that there are substantial sloshing side forces acting on the LH2 tank during the deceleration of the vehicle after MECO. The LH2 tank features a side wall drain pipe. The side loads result from the residual propellant mass motion in the LH2 tank which is initiated by the stop of flow into the drain pipe at MECO. The simulations show that radial force on the LH2 tank wall is less than 50 lbf and the radial moment calculated based up the center of gravity of the vehicle is predicted to be as high as 300 lbf-ft. The LO2 tank features a bottom dome drain system and is equipped with sloshing baffles. The remaining LO2 in the tank slowly forms a liquid column along the centerline of tank under the zero gravity environments. The radial force on the LO2 tank wall is predicted less than 100 lbf. The radial moment calculated based on the center of gravity of the vehicle is predicted as high as 4500 lbf-ft just before MECO and dropped down to near zero after propellant draining stopped completely.

  5. Numerical simulation methods of incompressible flows and an application to the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Chang, J. L. C.; Kwak, D.; Rogers, S. E.; Yang, R.-J.

    1988-01-01

    This paper discusses incompressible Navier-Stokes solution methods with an emphasis on the pseudocompressibility method. A steady-state flow solver based on the pseudocompressibility approach is then described. This flow solver code has been used to analyze the internal flow in the Space Shuttle main engine hot-gas manifold. Salient features associated with this three-dimensional realistic flow simulation are discussed. Numerical solutions relevant to the current engine analysis and the redesign effort are discussed along with experimental results. This example demonstrates the potential of computational fluid dynamics as a design tool for aerospace applications.

  6. Numerical simulation methods of incompressible flows and an application to the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Chang, J. L. C.; Kwak, D.; Rogers, S. E.; Yang, R.-J.

    1988-01-01

    Incompressible Navier-Stokes solution methods are discussed with an emphasis on the pseudocompressibility method. A steady-state flow solver based on the pseudocompressibility approach is then described. This flow-solver code was used to analyze the internal flow in the Space Shuttle main engine hot-gas manifold. Salient features associated with this three-dimensional realistic flow simulation are discussed. Numerical solutions relevant to the current engine analysis and the redesign effort are discussed along with experimental results. This example demonstrates the potential of computational fluid dynamics as a design tool for aerospace applications.

  7. Space Shuttle Main Engine Start with Off-Nominal Propellant Inlet Pressures

    NASA Technical Reports Server (NTRS)

    Bradley, Michael

    1997-01-01

    This paper describes Rocketdyne's successful analysis and demonstration of the Space Shuttle Main Engine (SSME) operation at off-nominal propellant inlet conditions during the Reusable Launch Vehicle (RLV) evaluation tests. The nominal inlet condition range is: 103 to 111 psia and 170.5 to 178 deg. R for the oxidizer and 43 to 47 psia and 37 to 40 deg. R for the fuel. The SSME start was successfully demonstrated with engine inlet pressures of 50 psia liquid oxygen (LOX) with subcooled LOX at 160 deg R and 38 psia fuel at 38 deg. R. Four tests were used to incrementally modify the start sequence to demonstrate the final goal.

  8. Binary interactions with high accretion rates onto main sequence stars

    NASA Astrophysics Data System (ADS)

    Shiber, Sagiv; Schreier, Ron; Soker, Noam

    2016-07-01

    Energetic outflows from main sequence stars accreting mass at very high rates might account for the powering of some eruptive objects, such as merging main sequence stars, major eruptions of luminous blue variables, e.g., the Great Eruption of Eta Carinae, and other intermediate luminosity optical transients (ILOTs; red novae; red transients). These powerful outflows could potentially also supply the extra energy required in the common envelope process and in the grazing envelope evolution of binary systems. We propose that a massive outflow/jets mediated by magnetic fields might remove energy and angular momentum from the accretion disk to allow such high accretion rate flows. By examining the possible activity of the magnetic fields of accretion disks, we conclude that indeed main sequence stars might accrete mass at very high rates, up to ≈ 10-2 M ⊙ yr-1 for solar type stars, and up to ≈ 1 M ⊙ yr-1 for very massive stars. We speculate that magnetic fields amplified in such extreme conditions might lead to the formation of massive bipolar outflows that can remove most of the disk's energy and angular momentum. It is this energy and angular momentum removal that allows the very high mass accretion rate onto main sequence stars.

  9. The main problems in the mechanical engineering sector and some possible directions of their solution

    NASA Astrophysics Data System (ADS)

    Strizhakova, E.

    2016-04-01

    The article shows the problems of the sector of mechanical engineering in the industrial system in Russia. The author's method of estimating the relative level of risk and the method of determining the de-industrialization degree of the sector based on the aggregated level of adaptability are given. According to them we have analysed the key indicators, such as basic, developed and advanced technologies, and investments in an old or new technology of industrial sectors. The main directions of the impact of industrial policy allowing a change in the current situation in mechanical engineering are given. The results can be applied in practice in formation of directions and actual control actions to improve the overall efficiency of mechanical engineering industry.

  10. Reliability growth modeling analysis of the space shuttle main engines based upon the Weibull process

    NASA Technical Reports Server (NTRS)

    Wheeler, J. T.

    1990-01-01

    The Weibull process, identified as the inhomogeneous Poisson process with the Weibull intensity function, is used to model the reliability growth assessment of the space shuttle main engine test and flight failure data. Additional tables of percentage-point probabilities for several different values of the confidence coefficient have been generated for setting (1-alpha)100-percent two sided confidence interval estimates on the mean time between failures. The tabled data pertain to two cases: (1) time-terminated testing, and (2) failure-terminated testing. The critical values of the three test statistics, namely Cramer-von Mises, Kolmogorov-Smirnov, and chi-square, were calculated and tabled for use in the goodness of fit tests for the engine reliability data. Numerical results are presented for five different groupings of the engine data that reflect the actual response to the failures.

  11. Viscous flow effects on hydrogen leaks from cracks in the Orbiter Challenger main engines

    NASA Technical Reports Server (NTRS)

    Goodrich, W. D.

    1984-01-01

    An analytical model was developed to provide additional insight and understanding of the factors that influence the simulation and prediction of leak rates from small cracks in pressurized containers. Specifically, the analysis was aimed at developing an analytical model capable of predicting the hydrogen leak rates from a crack in the combustion chamber coolant discharge manifold on main engine 1 of the Orbiter Challenger that was discovered during flight readiness firings 1 and 2. This model was based on viscous pipe flow analyses and calibrated for the crack geometry by using helium leak-rate data obtained from both low- and high-pressure tests used to simulate the flight readiness firing test conditions. In addition, this model includes the effects of crack width changes caused by different working stresses associated with the different test conditions. Because of the combination of the small crack dimensions and the wide range of pressures used for the test conditions, either laminar or turbulent viscous effects dominated the flows at all test conditions. This model was used to illustrate the sensitivity of the predicted leak rates to considerations of test conditions, viscous flow effects, and geometric features of the crack. In addition, the model was certified by comparing the hydrogen leak-rate prediction for the flight readiness firing test condition to the actual measured leak rate. The prediction was within 9 percent of the measured value.

  12. Calculation of flow about posts and powerhead model. [space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Anderson, P. G.; Farmer, R. C.

    1985-01-01

    A three dimensional analysis of the non-uniform flow around the liquid oxygen (LOX) posts in the Space Shuttle Main Engine (SSME) powerhead was performed to determine possible factors contributing to the failure of the posts. Also performed was three dimensional numerical fluid flow analysis of the high pressure fuel turbopump (HPFTP) exhaust system, consisting of the turnaround duct (TAD), two-duct hot gas manifold (HGM), and the Version B transfer ducts. The analysis was conducted in the following manner: (1) modeling the flow around a single and small clusters (2 to 10) of posts; (2) modeling the velocity field in the cross plane; and (3) modeling the entire flow region with a three dimensional network type model. Shear stress functions which will permit viscous analysis without requiring excessive numbers of computational grid points were developed. These wall functions, laminar and turbulent, have been compared to standard Blasius solutions and are directly applicable to the cylinder in cross flow class of problems to which the LOX post problem belongs.

  13. Preliminary analysis of selected gas dynamic problems. [space shuttle main engine main combustion transients and IUS nozzle flow

    NASA Technical Reports Server (NTRS)

    Prozan, R. J.; Farmer, R. C.

    1985-01-01

    The VAST computer code was used to analyze SSME main combustion chamber start-up transients and the IUS flow field for a damaged nozzle was investigated to better understand the gas dynamic considerations involved in vehicle problems, the effect of start transients on the nozzle flow field for the SSME, and the possibility that a damaged nozzle could account for the acceleration anomaly noted on IUS burn. The results obtained were compared with a method of characteristics prediction. Pressure solutions from both codes were in very good agreement and the Mach number solution on the nozzle centerline deviates substantially for the high expansions for the SSME. Since this deviation was unexpected, the phenomenon is being further examined.

  14. High frequency dynamic engine simulation. [TF-30 engine

    NASA Technical Reports Server (NTRS)

    Schuerman, J. A.; Fischer, K. E.; Mclaughlin, P. W.

    1977-01-01

    A digital computer simulation of a mixed flow, twin spool turbofan engine was assembled to evaluate and improve the dynamic characteristics of the engine simulation to disturbance frequencies of at least 100 Hz. One dimensional forms of the dynamic mass, momentum and energy equations were used to model the engine. A TF30 engine was simulated so that dynamic characteristics could be evaluated against results obtained from testing of the TF30 engine at the NASA Lewis Research Center. Dynamic characteristics of the engine simulation were improved by modifying the compression system model. Modifications to the compression system model were established by investigating the influence of size and number of finite dynamic elements. Based on the results of this program, high frequency engine simulations using finite dynamic elements can be assembled so that the engine dynamic configuration is optimum with respect to dynamic characteristics and computer execution time. Resizing of the compression systems finite elements improved the dynamic characteristics of the engine simulation but showed that additional refinements are required to obtain close agreement simulation and actual engine dynamic characteristics.

  15. Investigation of instability, dynamic forces, and effect of dynamic loading on strength of cages for the bearings in the high pressure oxygen turbopumps for the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Dufrane, K. F.; Kannel, J. W.; Merriman, T. L.; Rosenfield, A. R.

    1985-01-01

    Experiments were performed to determine the effect of cyclic loading on bearing cage strength. A long term working tensile load of approximately 1300 N (300 lbs) was found to be the likely maximum. Higher loads caused a decrease in cage tensile strength after the 125,000 cycle testing period. Poisson's ratio in compression was found to be highly dependent upon the direction of the fiberglass plies. At room temperature the value was 0.15 with the plies and 0.68 across the plies. At -196 C (-321 F), the value with the plies was 0.20. The results of the analyses conducted have again demonstrated the critical need for improved lubrication in the high pressure oxygen turbopump bearings. Lubricant films with low shear strength and low friction coefficients promote cage stability and decrease ball/cage forces during marginal operating conditions. The analysis of the effect of combined bearing loads on ball/cage loads has identified a radial load of 3600 N (800 lbs) as the maximum for the current clearance of the balls and cage pockets. Liquid oxygen impinging on the cage in the direction of rotation was found to enhance cage stability.

  16. Real gas properties and Space Shuttle Main Engine fuel turbine performance prediction

    NASA Technical Reports Server (NTRS)

    Harloff, G. J.

    1987-01-01

    The H2/H2O mixture thermodynamic and transport properties variations for the Space Shuttle Main Engine (SSME) fuel turbine over a range of temperatures and pressures are examined. The variation of molecular viscosity, specific heat at constant pressure, and Prandtl number for the hydrogen/steam mixture are fitted using polynominal relationships for future turbine performance use. The mixture property variations are calculated using GASP and WASP computer programs. The air equivalent performance of the SSME fuel turbine is computed.

  17. Real gas properties and Space Shuttle Main Engine fuel turbine performance prediction

    NASA Technical Reports Server (NTRS)

    Harloff, G. J.

    1987-01-01

    The H2/H2O mixture thermodynamic and transport properties variations for the Space Shuttle Main Engine (SSME) fuel turbine over a range of temperatures and pressures are examined. The variation of molecular viscosity, specific heat at constant pressure, and Prandtl number for the hydrogen/steam mixture are fitted using polynominal relationships for future turbine performance use. The mixture property variations are calculated using GASP and WASP computer programs. The air equivalent performance of the SSME fuel turbine is computed.

  18. Phased Array Ultrasonic Examination of Space Shuttle Main Engine Nozzle Weld

    NASA Technical Reports Server (NTRS)

    James, S.; Engel, J.; Kimbrough, D.; Suits, M.; McCool, Alex (Technical Monitor)

    2001-01-01

    This paper describes a Phased Array Ultrasonic Examination that was developed for the examination of a limited access circumferential Inconel 718 fusion weld of a Space Shuttle Main Engine Nozzle - Cone. The paper discusses the selection and formation criteria used for the phased array focal laws, the reference standard that simulated hardware conditions, the examination concept, and results. Several unique constraints present during this examination included limited probe movement to a single axis and one-sided access to the weld.

  19. A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix B: Data base plots for SSME tests 901-290 through 901-414

    NASA Technical Reports Server (NTRS)

    Coffin, T.

    1986-01-01

    A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is described. The data base represents dynamic pressure measurements obtained during single engine hot firing tesets of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is also included to estimate spectral trends with SSME power level. Flow dynamic environments in high performance rocket engines are discussed.

  20. A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix C: Data base plots for SSME tests 902-214 through 902-314

    NASA Technical Reports Server (NTRS)

    Coffin, T.

    1986-01-01

    A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is reported. The data base represents dynamic pressure measurements obtained during single engine hot firing tests of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is included to estimate spectral trends with SSME power level. Flow Dynamic Environments in High Performance Rocket Engines are described.

  1. Fermilab main injector: High intensity operation and beam loss control

    NASA Astrophysics Data System (ADS)

    Brown, Bruce C.; Adamson, Philip; Capista, David; Chou, Weiren; Kourbanis, Ioanis; Morris, Denton K.; Seiya, Kiyomi; Wu, Guan Hong; Yang, Ming-Jen

    2013-07-01

    From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at 400 kW beam power. Transmission was very high except for beam lost at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the improvements required to achieve high intensity, the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

  2. Space Shuttle Main Engine Implications for the Abort-to-Orbit Off-the-Pad Study

    NASA Technical Reports Server (NTRS)

    Schoffstoll, Dayna L.

    2003-01-01

    In 2001, the Space Shuttle Main Engine (SSME) project office was contacted by the Space Shuttle Ascent Guidance, Navigation, and Control group to provide the engine perspective for an Abort-to-Orbit (ATO) study. The purpose of the AT0 Off-the-Pad study was to determine the feasibility of eliminating the Return to Launch Site and Transatlantic abort modes by using a five-segment solid rocket booster and throttling the remaining SSMEs to a higher power level. This would enable all abort modes to be Abort-to-Orbit. The SSME project office at Marshall Space Flight Center collaborated with MSFC's Space Transportation Directorate and Rocketdyne Propulsion and Power to provide the AT0 Off-the-Pad study with the analysis required. Power levels at 109%, 1 11% and 1 13% of rated power level were studied as well as mixture ratio decreases down to 5.85. SSME was to evaluate and define the technical and programmatic impacts to certify the SSME to these abort power levels. The SSME systems analysis group performed a steady state analysis using the SSME power balance model to determine if there were any technical issues associated with higher power level, low mixture ratio operation. Based on each power level/mixture ratio combination, an engine certification plan was created and a preliminary probabilistic risk assessment was performed. The results showed favorable results for higher power 1evel/lower mixture ratio SSME operation. In nearly all performance and redline parameters, the traded engine operation was encompassed by nominal engine performance of a prior engine configuration.

  3. Aerodynamic evaluation of the redesigned Space Shuttle Main Engine hot-gas manifold

    NASA Technical Reports Server (NTRS)

    Vogt, S. T.; Cuan, W. M.; Hoehn, F. W.; Kim, B. Y.; Oconnor, G. M.; Richards, D. R.

    1985-01-01

    The current Space Shuttle Main Engine hot-gas manifold configuration contains three transfer ducts connecting the fuel bowl and the main injector torus. For the current study, a new hot-gas manifold was designed to improve on a previously tested two-duct concept. This was accomplished by eliminating separated flow regions, reducing local velocities, and providing as uniform a flowfield as possible. The two-duct hot-gas manifold tested in this study showed significant improvement over the existing three-duct design. The circumferential pressure gradient was reduced by 67 percent. The system total pressure loss from the discharge of the 180-degree turn to the transfer duct exit was 60 percent less than with the three duct hot gas manifold. Although only limited fluctuating pressure data were taken in the main injector, indications are that the environment there has been improved.

  4. Booster Main Engine Selection Criteria for the Liquid Fly-Back Booster

    NASA Technical Reports Server (NTRS)

    Ryan, Richard M.; Rothschild, William J.; Christensen, David L.

    1998-01-01

    The Liquid Fly-Back Booster (LFBB) Program seeks to enhance the Space Shuttle system safety, performance and economy of operations through the use of an advanced, liquid propellant Booster Main Engine (BME). There are several viable BME candidates that could be suitable for this application. The objective of this study was to identify the key Criteria to be applied in selecting among these BME candidates. This study involved an assessment of influences on the overall LFBB utility due to variations in the candidate rocket-engines characteristics. This includes BME impacts on vehicle system weight, performance, design approaches, abort modes, margins of safety, engine-out operations, and maintenance and support concepts. Systems engineering analyses and trade studies were performed to identify the LFBB system level sensitivities to a wide variety of BME related parameters. This presentation summarizes these trade studies and the resulting findings of the LFBB design teams regarding the BME characteristics that most significantly affect the LFBB system. The resulting BME choice should offer the best combination of reliability, performance, reusability, robustness, cost, and risk for the LFBB program.

  5. Booster Main Engine Selection Criteria for the Liquid Fly-Back Booster

    NASA Technical Reports Server (NTRS)

    Ryan, Richard M.; Rothschild, William J.; Christensen, David L.

    1998-01-01

    The Liquid Fly-Back Booster (LFBB) Program seeks to enhance the Space Shuttle system safety performance and economy of operations through the use of an advanced, liquid propellant Booster Main Engine (BME). There are several viable BME candidates that could be suitable for this application. The objective of this study was to identify the key criteria to be applied in selecting among these BME candidates. This study involved an assessment of influences on the overall LFBB utility due to variations in the candidate rocket engines' characteristics. This includes BME impacts on vehicle system weight, perfortnance,design approaches, abort modes, margins of safety, engine-out operations, and maintenance and support concepts. Systems engineering analyses and trade studies were performed to identify the LFBB system level sensitivities to a wide variety of BME related parameters. This presentation summarizes these trade studies and the resulting findings of the LFBB design teams regarding the BME characteristics that most significantly affect the LFBB system. The resulting BME choice should offer the best combination of reliability, performance, reusability, robustness, cost, and risk for the LFBB program.

  6. High Reliability Engine Control Demonstrated for Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei

    1999-01-01

    For a dual redundant-control system, which is typical for short-haul aircraft, if a failure is detected in a control sensor, the engine control is transferred to a safety mode and an advisory is issued for immediate maintenance action to replace the failed sensor. The safety mode typically results in severely degraded engine performance. The goal of the High Reliability Engine Control (HREC) program was to demonstrate that the neural-network-based sensor validation technology can safely operate an engine by using the nominal closed-loop control during and after sensor failures. With this technology, engine performance could be maintained, and the sensor could be replaced as a conveniently scheduled maintenance action.

  7. Structural integrity and durability for Space Shuttle main engine and future reusable space propulsion systems

    NASA Technical Reports Server (NTRS)

    Marsik, S. J.; Gawrylowicz, H. T.

    1986-01-01

    NASA is conducting a program which will establish a technology base for the orderly evolution of reusable space propulsion systems. As part of that program, NASA initiated a Structural Integrity and Durability effort for advanced high-pressure oxygen-hydrogen rocket engine technology. That effort focuses on the development of: (1) accurate analytical models to describe flow fields; aerothermodynamic loads; structural responses; and fatigue/fracture, from which life prediction codes can be evolved; and (2) advanced instrumentation with capabilities to verify the codes in an SSME-like environment as well as the potential for future use as diagnostic sensors for real-time condition monitoring of critical engine components.

  8. Pratt and Whitney Rocketdyne Space Shuttle Main Engine Heritage Commemorative: Powerhead and Ducts, Test and Flight Operations

    NASA Technical Reports Server (NTRS)

    Cook, Jerry R.; Willis, Martha

    2009-01-01

    The videos (Powerhead and Ducts, Test and Flight Operations) review the Space Shuttle Main Engine (SSME) program from Pratt and Whitney Rocketdyne. They include highlights from the engine's development and lifecycle through the engine testing to the deployment in the space shuttle.

  9. Pratt and Whitney Rocketdyne Space Shuttle Main Engine Heritage Commemorative: Powerhead and Ducts, Test and Flight Operations

    NASA Technical Reports Server (NTRS)

    Cook, Jerry R.; Willis, Martha

    2009-01-01

    The videos (Powerhead and Ducts, Test and Flight Operations) review the Space Shuttle Main Engine (SSME) program from Pratt and Whitney Rocketdyne. They include highlights from the engine's development and lifecycle through the engine testing to the deployment in the space shuttle.

  10. Preliminary analysis of lineaments and engineering properties of bedrock, Penobscot Bay area, Maine

    USGS Publications Warehouse

    Lee, Fitzhugh T.; O'Leary, Dennis W.; Diehl, Sharon F.

    1977-01-01

    A remote sensing study of coastal and near coastal Maine was undertaken to identify bedrock features of possible importance to construction. Major lineaments were identified that separate the region into four distinct terrains. Within each terrain, smaller lineaments and other physiographic features show distinctive and consistent patterns, reflecting similarities in bedrock lithology and structure. The major linear features are given the following provisional geographic names: I. Lewiston line 2. Merrymeeting lineament 3. Dover-Foxcroft line 4. Orland lineament 5. Union lineament These linear or curvilinear trends are caused by lithologic contrasts, joints, faults, or foliation in the middle and lower Paleozoic phyllites, schists, gneisses, and granite intrusives. Initial field and laboratory results from a pilot study of bedrock engineering conditions indicate that variations in rock strength and fracture spacing are controlled by lithology, intensity of structural deformation, and alteration. At several locations in the study area faults and major joints are alined with a major lineament. Strength anisotropy ratios are as high as 10 in the foliated rocks but near 1 in the granites. The higher compressive strength direction commonly is perpendicular to foliation and to lineament trends which, in turn, are parallel to faults, major joints, or foliation. Fracture spacing in rocks in the field study area averages 0.5 m for granite and ranges from 0.2 cm to 0.75 m, with an average of 0.15 m, in metamorphic rocks. Diagnostic indications useful for estimating certain construction conditions are shown by point-load and uniaxial compressive strengths. Values for fresh rock range from less than 30 MN/m 2 for weakly bonded phyllite to more than 350 MN/m 2 for dense andesite and metasiltstone. Rock workability is directly related to compressive strength and spacing of joints.

  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. Operating manual for coaxial injection combustion model. [for the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Sutton, R. D.; Schuman, M. D.; Chadwick, W. D.

    1974-01-01

    An operating manual for the coaxial injection combustion model (CICM) is presented as the final report for an eleven month effort designed to provide improvement, to verify, and to document the comprehensive computer program for analyzing the performance of thrust chamber operation with gas/liquid coaxial jet injection. The effort culminated in delivery of an operation FORTRAN IV computer program and associated documentation pertaining to the combustion conditions in the space shuttle main engine. The computer program is structured for compatibility with the standardized Joint Army-Navy-NASA-Air Force (JANNAF) performance evaluation procedure. Use of the CICM in conjunction with the JANNAF procedure allows the analysis of engine systems using coaxial gas/liquid injection.

  13. Off-line programming motion and process commands for robotic welding of Space Shuttle main engines

    NASA Technical Reports Server (NTRS)

    Ruokangas, C. C.; Guthmiller, W. A.; Pierson, B. L.; Sliwinski, K. E.; Lee, J. M. F.

    1987-01-01

    The off-line-programming software and hardware being developed for robotic welding of the Space Shuttle main engine are described and illustrated with diagrams, drawings, graphs, and photographs. The menu-driven workstation-based interactive programming system is designed to permit generation of both motion and process commands for the robotic workcell by weld engineers (with only limited knowledge of programming or CAD systems) on the production floor. Consideration is given to the user interface, geometric-sources interfaces, overall menu structure, weld-parameter data base, and displays of run time and archived data. Ongoing efforts to address limitations related to automatic-downhand-configuration coordinated motion, a lack of source codes for the motion-control software, CAD data incompatibility, interfacing with the robotic workcell, and definition of the welding data base are discussed.

  14. Potential SSME modifications to provide extended capabilities for future applications. [Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Kirby, F. M.

    1978-01-01

    Expendable launch vehicles will be phased out during the first years of shuttle operation and the payloads currently carried to orbit by these vehicles will be placed in low earth orbit by the reusable shuttle. In connection with limitations regarding the weight of the payload which can be launched by the Space Shuttle in its present form, approaches have been considered for increasing the payload capability of the Shuttle. Propulsion systems for Shuttle derived vehicles with larger payload capabilities have been studied. Such systems can potentially be obtained from modifications of the Space Shuttle Main Engine (SSME). Concepts based on modifications to the basic engine include an SSME-35 for low altitude operation with liquid rocket boosters and an SSME-150 for operation over the complete altitude range as might be required in a single-stage-to-orbit vehicle application. Another modification would provide operation with a hydrocarbon fuel instead of hydrogen.

  15. Space shuttle main engine definition (phase B). Volume 5: Valves and interconnects. [for space shuttle

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1971-01-01

    The steady state thermodynamic cycle balance of the single preburner staged combustion engine, coupled with dynamic transient analyses, dictated in detail the location and requirements for each valve defined in this volume. Valve configuration selections were influenced by overall engine and vehicle system weight and failure mode determinations. Modulating valve actuators are external to the valve and are line replaceable. Development and satisfactory demonstration of a high pressure dynamic shaft seal has made this configuration practical. Pneumatic motor driven actuators that use engine pumped hydrogen gas as the working fluid are used. The helium control system is proposed as a module containing a cluster of solenoid actuated valves. The separable couplings and flanges are designed to assure minimum leakage with minimum coupling weight. The deflection of the seal surface in the flange is defined by finite element analysis that has been confirmed with test data. The seal design proposed has passed preliminary pressure cycling and thermal cycling tests.

  16. PBF Reactor Building (PER620). Inside high bay on main floor. ...

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

    PBF Reactor Building (PER-620). Inside high bay on main floor. Reactor pit is covered with metal platform. Control rod actuating mechanisms protrude above bridge. Reactor is still two years away from its first critically. Note floor hatch at lower right of view and elsewhere. Photographer: Kirsh. Date: November 19, 1970. INEEL negative no. 70-5216 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  17. Study of hydraulic actuation system for Space Shuttle main engine propellant valves

    NASA Technical Reports Server (NTRS)

    Ewel, Bob (Editor)

    1993-01-01

    Recent performance concerns involving the Space Shuttle Main Engine Propellant Valve Actuator assemblies prompted the NASA Marshall Space Flight Center to request an independent design assessment. Moog Inc. responded to this request and received a study contract with objectives of increasing valve reliability, decreasing maintenance costs while preserving the existing design interfaces. The results of the Propellant Valve Actuation System review focus on contamination control and the bypass valve design. Three proof of concept bypass valves employing design changes were built and successfully tested. Test results are presented.

  18. Phased Array Ultrasonic Evaluation of Space Shuttle Main Engine (SSME) Nozzle Weld

    NASA Technical Reports Server (NTRS)

    James, Steve; Engel, J.; Kimbrough, D.; Suits, M.; Hopson, George (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of the phased array ultrasonic evaluation of the Space Shuttle Main Engine (SSME) nozzle weld. Details are given on the nondestructive testing evaluation approach, conventional shear wave and phased array techniques, and an x-ray versus phased array risk analysis. The field set-up was duplicated to the greatest extent possible in the laboratory and the phased array ultrasonic technique was developed and validated prior to weld evaluation. Results are shown for the phased array ultrasonic evaluation and conventional ultrasonic evaluation results.

  19. Thrust chamber performance using Navier-Stokes solution. [space shuttle main engine viscous nozzle calculation

    NASA Technical Reports Server (NTRS)

    Chan, J. S.; Freeman, J. A.

    1984-01-01

    The viscous, axisymmetric flow in the thrust chamber of the space shuttle main engine (SSME) was computed on the CRAY 205 computer using the general interpolants method (GIM) code. Results show that the Navier-Stokes codes can be used for these flows to study trends and viscous effects as well as determine flow patterns; but further research and development is needed before they can be used as production tools for nozzle performance calculations. The GIM formulation, numerical scheme, and computer code are described. The actual SSME nozzle computation showing grid points, flow contours, and flow parameter plots is discussed. The computer system and run times/costs are detailed.

  20. Investigations for the improvement of space shuttle main engine electron beam welding equipment

    NASA Technical Reports Server (NTRS)

    Smock, R. A.; Taylor, R. A.; Wall, W. A., Jr.

    1977-01-01

    Progress made in the testing, evaluation, and correction of MSFC's 7.5 kW electron beam welder in support of space shuttle main engine component welding is summarized. The objective of this project was to locate and correct the deficiencies in the welder. Some 17 areas were deficient in the 7.5 kW ERI welding system and the associated corrective action was taken to improve its operational performance. An overall improvement of 20 times the original reliability was obtained at full rated capacity after the modifications were made.

  1. Sen. John C. Stennis celebrates a successful Space Shuttle Main Engine test

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Sen. John C. Stennis dances a jig on top of the Test Control Center at Stennis Space Center following the successful test of a Space Shuttle Main Engine in 1978. A staunch supporter of the National Aeronautics and Space Administration (NASA), the senior senator from DeKalb, Miss., supported the establishment of the space center in Hancock County and spoke personally with local residents who would relocate their homes to accommodate Mississippi's entry into the space age. Stennis Space Center was named for Sen. Stennis by Executive Order of President Ronald Reagan on May 20, 1988.

  2. Spares Management : Optimizing Hardware Usage for the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Gulbrandsen, K. A.

    1999-01-01

    The complexity of the Space Shuttle Main Engine (SSME), combined with mounting requirements to reduce operations costs have increased demands for accurate tracking, maintenance, and projections of SSME assets. The SSME Logistics Team is developing an integrated asset management process. This PC-based tool provides a user-friendly asset database for daily decision making, plus a variable-input hardware usage simulation with complex logic yielding output that addresses essential asset management issues. Cycle times on critical tasks are significantly reduced. Associated costs have decreased as asset data quality and decision-making capability has increased.

  3. Sen. John C. Stennis celebrates a successful Space Shuttle Main Engine test

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Sen. John C. Stennis dances a jig on top of the Test Control Center at Stennis Space Center following the successful test of a Space Shuttle Main Engine in 1978. A staunch supporter of the National Aeronautics and Space Administration (NASA), the senior senator from DeKalb, Miss., supported the establishment of the space center in Hancock County and spoke personally with local residents who would relocate their homes to accommodate Mississippi's entry into the space age. Stennis Space Center was named for Sen. Stennis by Executive Order of President Ronald Reagan on May 20, 1988.

  4. Spares Management : Optimizing Hardware Usage for the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Gulbrandsen, K. A.

    1999-01-01

    The complexity of the Space Shuttle Main Engine (SSME), combined with mounting requirements to reduce operations costs have increased demands for accurate tracking, maintenance, and projections of SSME assets. The SSME Logistics Team is developing an integrated asset management process. This PC-based tool provides a user-friendly asset database for daily decision making, plus a variable-input hardware usage simulation with complex logic yielding output that addresses essential asset management issues. Cycle times on critical tasks are significantly reduced. Associated costs have decreased as asset data quality and decision-making capability has increased.

  5. Study of hydraulic actuation system for Space Shuttle main engine propellant valves

    NASA Astrophysics Data System (ADS)

    Ewel, Bob

    1993-06-01

    Recent performance concerns involving the Space Shuttle Main Engine Propellant Valve Actuator assemblies prompted the NASA Marshall Space Flight Center to request an independent design assessment. Moog Inc. responded to this request and received a study contract with objectives of increasing valve reliability, decreasing maintenance costs while preserving the existing design interfaces. The results of the Propellant Valve Actuation System review focus on contamination control and the bypass valve design. Three proof of concept bypass valves employing design changes were built and successfully tested. Test results are presented.

  6. Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5

    NASA Technical Reports Server (NTRS)

    Anderson, P. J.; Nussbaum, P.; Gustafson, G.

    1984-01-01

    The objective of the research project described is to define and demonstrate methods to advance the state of the art of pressure sensors for the space shuttle main engine (SSME). Silicon piezoresistive technology was utilized in completing tasks: generation and testing of three transducer design concepts for solid state applications; silicon resistor characterization at cryogenic temperatures; experimental chip mounting characterization; frequency response optimization and prototype design and fabrication. Excellent silicon sensor performance was demonstrated at liquid nitrogen temperature. A silicon resistor ion implant dose was customized for SSME temperature requirements. A basic acoustic modeling software program was developed as a design tool to evaluate frequency response characteristics.

  7. Numerical analysis of SSME preburner injector atomization and combustion processes. [Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Liang, P. Y.; Jensen, R. J.; Chang, Y. M.

    1986-01-01

    The coaxial spray injection and combustion flowfields of a Space Shuttle Main Engine preburner injector element have been analyzed using a three-phase numerical code. The processes of atomization, evaporation, secondary droplet breakup, and multispecies chemistry, as well as turbulent diffusion, are included. The model produced realistic pictures of the complex internal flowfield, including liquid jet length, spray shape, flame-zone size and characteristics, and predicted temperatures that seem to be in agreement with test data envelopes. It predicted an external group combustion type of flame. Salient combustion and mixing features are discussed and sources of uncertainty are pointed out for future studies.

  8. Investigation and modeling of space shuttle main engine shutdown transient chugging

    NASA Technical Reports Server (NTRS)

    George, P. E., II

    1986-01-01

    The space shuttle main engines experience a low frequency pressure pulsation in both the fuel and oxidizer preburners during the shutdown transient. This pressure pulsation, called chugging, has been linked to undesirable bearing loads and possible damage to the spark ignitor supply piping for the fuel preburner. The problem is briefly described and a model is proposed that includes: (1) a transient stirred tank reactor model for the combustion chamber, (2) a resistance capacitance model for the supply piping and (3) purge gas/liquid oxygen interface tracking.

  9. National Aerospace Plane Engine Seals: High Temperature Seal Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.

    1991-01-01

    The key to the successful development of the single stage to orbit National Aerospace Plane (NASP) is the successful development of combined cycle ramjet/scramjet engines that can propel the vehicle to 17,000 mph to reach low Earth orbit. To achieve engine performance over this speed range, movable engine panels are used to tailor engine flow that require low leakage, high temperature seals around their perimeter. NASA-Lewis is developing a family of new high temperature seals to form effective barriers against leakage of extremely hot (greater than 2000 F), high pressure (up to 100 psi) flow path gases containing hydrogen and oxygen. Preventing backside leakage of these explosive gas mixtures is paramount in preventing the potential loss of the engine or the entire vehicle. Seal technology development accomplishments are described in the three main areas of concept development, test, and evaluation and analytical development.

  10. Specialized data analysis for the Space Shuttle Main Engine and diagnostic evaluation of advanced propulsion system components

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Marshall Space Flight Center is responsible for the development and management of advanced launch vehicle propulsion systems, including the Space Shuttle Main Engine (SSME), which is presently operational, and the Space Transportation Main Engine (STME) under development. The SSME's provide high performance within stringent constraints on size, weight, and reliability. Based on operational experience, continuous design improvement is in progress to enhance system durability and reliability. Specialized data analysis and interpretation is required in support of SSME and advanced propulsion system diagnostic evaluations. Comprehensive evaluation of the dynamic measurements obtained from test and flight operations is necessary to provide timely assessment of the vibrational characteristics indicating the operational status of turbomachinery and other critical engine components. Efficient performance of this effort is critical due to the significant impact of dynamic evaluation results on ground test and launch schedules, and requires direct familiarity with SSME and derivative systems, test data acquisition, and diagnostic software. Detailed analysis and evaluation of dynamic measurements obtained during SSME and advanced system ground test and flight operations was performed including analytical/statistical assessment of component dynamic behavior, and the development and implementation of analytical/statistical models to efficiently define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational condition. In addition, the SSME and J-2 data will be applied to develop vibroacoustic environments for advanced propulsion system components, as required. This study will provide timely assessment of engine component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. This contract will be performed through accomplishment of negotiated task orders.

  11. Characterization of real gas properties for space shuttle main engine fuel turbine and performance calculations

    NASA Technical Reports Server (NTRS)

    Harloff, G. J.

    1986-01-01

    Real thermodynamic and transport properties of hydrogen, steam, the SSME mixture, and air are developed. The SSME mixture properties are needed for the analysis of the space shuttle main engine fuel turbine. The mixture conditions for the gases, except air, are presented graphically over a temperature range from 800 to 1200 K, and a pressure range from 1 to 500 atm. Air properties are given over a temperature range of 320 to 500 K, which are within the bounds of the thermodynamics programs used, in order to provide mixture data which is more easily checked (than H2/H2O). The real gas property variation of the SSME mixture is quantified. Polynomial expressions, needed for future computer analysis, for viscosity, Prandtl number, and thermal conductivity are given for the H2/H2O SSME fuel turbine mixture at a pressure of 305 atm over a range of temperatures from 950 to 1140 K. These conditions are representative of the SSME turbine operation. Performance calculations are presented for the space shuttle main engine (SSME) fuel turbine. The calculations use the air equivalent concept. Progress towards obtaining the capability to evaluate the performance of the SSME fuel turbine, with the H2/H2O mixture, is described.

  12. HIGH ECLIPTIC LATITUDE SURVEY FOR SMALL MAIN-BELT ASTEROIDS

    SciTech Connect

    Terai, Tsuyoshi; Takahashi, Jun; Itoh, Yoichi

    2013-11-01

    Main-belt asteroids have been continuously colliding with one another since they were formed. Their size distribution is primarily determined by the size dependence of asteroid strength against catastrophic impacts. The strength scaling law as a function of body size could depend on collision velocity, but the relationship remains unknown, especially under hypervelocity collisions comparable to 10 km s{sup –1}. We present a wide-field imaging survey at an ecliptic latitude of about 25° for investigating the size distribution of small main-belt asteroids that have highly inclined orbits. The analysis technique allowing for efficient asteroid detections and high-accuracy photometric measurements provides sufficient sample data to estimate the size distribution of sub-kilometer asteroids with inclinations larger than 14°. The best-fit power-law slopes of the cumulative size distribution are 1.25 ± 0.03 in the diameter range of 0.6-1.0 km and 1.84 ± 0.27 in 1.0-3.0 km. We provide a simple size distribution model that takes into consideration the oscillations of the power-law slope due to the transition from the gravity-scaled regime to the strength-scaled regime. We find that the high-inclination population has a shallow slope of the primary components of the size distribution compared to the low-inclination populations. The asteroid population exposed to hypervelocity impacts undergoes collisional processes where large bodies have a higher disruptive strength and longer lifespan relative to tiny bodies than the ecliptic asteroids.

  13. Evaluation of candidate metals in a simulated space shuttle main engine environment for application as turbine blade dampers

    NASA Technical Reports Server (NTRS)

    Caveny, L. H.; Morris, S. O.

    1979-01-01

    The high-pressure pumps for the space shuttle main engine are driven by combustion products which are 50 percent H2 and 50 percent H2O (by weight). The Haynes alloy 188, used in the dampers, experienced erosion. The erosion producing characteristics of wet H2 were evaluated using a controlled environment produced by a ballistic compressor. Four candidate materials were evaluated: H-188, A-286, Pt/Rh and Rh. Rh was clearly the most erosion resistant. Comparisons with AISI 4340 and Fe specimens of known uniformity indicate that metallurgical defects in the candidate materials are primary contributors to the higher than usual erosion.

  14. Current and Future High Power Operation of Fermilab Main Injector

    SciTech Connect

    Kourbanis, I.; Adamson, P.; Brown, B.; Capista, D.; Chou, W.; Morris, D.; Seyia, K.; Wu, G.; Yang, M.J.; /Fermilab

    2009-04-01

    Fermilab's Main Injector on acceleration cycles to 120 GeV has been running a mixed mode operation delivering beam to both the antiproton source for pbar production and to the NuMI[1] target for neutrino production since 2005. On January 2008 the slip stacking process used to increase the beam to the pbar target was expanded to include the beam to the NuMI target increasing the MI beam power at 120 GeV to 400KW. The current high power MI operation will be described along with the plans to increase the power to 700KW for NOvA and to 2.1 MW for project X.

  15. Automation based on knowledge modeling theory and its applications in engine diagnostic systems using Space Shuttle Main Engine vibrational data. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Kim, Jonnathan H.

    1995-01-01

    Humans can perform many complicated tasks without explicit rules. This inherent and advantageous capability becomes a hurdle when a task is to be automated. Modern computers and numerical calculations require explicit rules and discrete numerical values. In order to bridge the gap between human knowledge and automating tools, a knowledge model is proposed. Knowledge modeling techniques are discussed and utilized to automate a labor and time intensive task of detecting anomalous bearing wear patterns in the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP).

  16. New High in Engineering Degree Production. Facts

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2010

    2010-01-01

    Several of the state's key industry sectors depend heavily on employees with advanced scientific, analytic and technical knowledge. Among the fields closely related to these sectors, engineering degrees have posted the largest gain. This paper presents details on the following facts: (1) 2009 represented a record high for engineering degrees; (2)…

  17. Space Shuttle main engine OPAD: The search for a hardware enhanced plume

    NASA Technical Reports Server (NTRS)

    Powers, W. T.; Cooper, A. E.; Wallace, Tim L.; Buntine, W. L.; Whitaker, K. W.

    1993-01-01

    The process of applying spectroscopy to the Space Shuttle Main Engine (SSME) for plume diagnostics, as it exists today, originated at Marshall Space Flight Center in Huntsville, Alabama, and its implementation was assured largely through the efforts of Sverdrup AEDC, in Tullahoma, Tennessee. This team continues to lead and guide efforts in the plume diagnostics arena. The process, Optical Plume Anomaly Detection (OPAD), formed the basis for various activities in the development of ground-based systems as well as the development of in-flight plume spectroscopy. OPAD currently provides and will continue to provide valuable information relative to future systems definitions, instrumentation development, code validation, and data diagnostic processing. OPAD is based on the detection of anomalous atomic and molecular species in the SSME plume using two complete, stand-alone optical spectrometers. To-date OPAD has acquired data on 44 test firings of the SSME at the Technology Test Bed (TTB) at MSFC. The purpose of this paper will be to provide an introduction to the OPAD system by discussing the process of obtaining data as well as the methods of examining and interpreting the data. It will encompass such issues as selection of instrumentation correlation of data to nominal engine operation, investigation of SSME component erosion via OPAD spectral data, necessity and benefits of plume seeding, application of artificial intelligence (AI) techniques to data analysis, and the present status of efforts to quantify specie erosion utilizing standard plume and chemistry codes as well as radiative models currently under development.

  18. Space Shuttle main engine OPAD: The search for a hardware enhanced plume

    NASA Technical Reports Server (NTRS)

    Powers, W. T.; Cooper, A. E.; Wallace, Tim L.; Buntine, W. L.; Whitaker, K. W.

    1993-01-01

    The process of applying spectroscopy to the Space Shuttle Main Engine (SSME) for plume diagnostics, as it exists today, originated at Marshall Space Flight Center in Huntsville, Alabama, and its implementation was assured largely through the efforts of Sverdrup AEDC, in Tullahoma, Tennessee. This team continues to lead and guide efforts in the plume diagnostics arena. The process, Optical Plume Anomaly Detection (OPAD), formed the basis for various activities in the development of ground-based systems as well as the development of in-flight plume spectroscopy. OPAD currently provides and will continue to provide valuable information relative to future systems definitions, instrumentation development, code validation, and data diagnostic processing. OPAD is based on the detection of anomalous atomic and molecular species in the SSME plume using two complete, stand-alone optical spectrometers. To-date OPAD has acquired data on 44 test firings of the SSME at the Technology Test Bed (TTB) at MSFC. The purpose of this paper will be to provide an introduction to the OPAD system by discussing the process of obtaining data as well as the methods of examining and interpreting the data. It will encompass such issues as selection of instrumentation correlation of data to nominal engine operation, investigation of SSME component erosion via OPAD spectral data, necessity and benefits of plume seeding, application of artificial intelligence (AI) techniques to data analysis, and the present status of efforts to quantify specie erosion utilizing standard plume and chemistry codes as well as radiative models currently under development.

  19. Analysis of internal flows relative to the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Cooperative efforts between the Lockheed-Huntsville Computational Mechanics Group and the NASA-MSFC Computational Fluid Dynamics staff has resulted in improved capabilities for numerically simulating incompressible flows generic to the Space Shuttle Main Engine (SSME). A well established and documented CFD code was obtained, modified, and applied to laminar and turbulent flows of the type occurring in the SSME Hot Gas Manifold. The INS3D code was installed on the NASA-MSFC CRAY-XMP computer system and is currently being used by NASA engineers. Studies to perform a transient analysis of the FPB were conducted. The COBRA/TRAC code is recommended for simulating the transient flow of oxygen into the LOX manifold. Property data for modifying the code to represent LOX/GOX flow was collected. The ALFA code was developed and recommended for representing the transient combustion in the preburner. These two codes will couple through the transient boundary conditions to simulate the startup and/or shutdown of the fuel preburner. A study, NAS8-37461, is currently being conducted to implement this modeling effort.

  20. Fatigue behavior of two alloys for Space Shuttle applications. [Inconel 903 and 718 for main engine

    NASA Technical Reports Server (NTRS)

    Adsit, N. R.; Block, S. J.

    1978-01-01

    Two superalloys used extensively in the Space Shuttle main engine are Incoloy 903 and Inconel 718. The fatigue behavior of the two alloys under varying conditions is considered. Three heats of Incoloy 903 and two of Inconel 718 were used in the study. Material was tested in several conditions, including mill polish, longitudinal mill polish, transverse mill polish, chemically milled, chemically milled plus shotpeened on one side and on both sides, gas tungsten arc welded, and electron beam welded. Both round and flat tensile specimens were tested in universal test machines. It was found that surface condition influences test results. Transverse scratches resulting from polishing and rougher surfaces lower the stress at runout in relation to that obtained on longitudinally polished and/or smooth-surfaced specimens.

  1. Space Shuttle Main Engine (SSME) LOX turbopump pump-end bearing analysis

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A simulation of the shaft/bearing system of the Space Shuttle Main Engine Liquid Oxygen turbopump was developed. The simulation model allows the thermal and mechanical characteristics to interact as a realistic simulation of the bearing operating characteristics. The model accounts for single and two phase coolant conditions, and includes the heat generation from bearing friction and fluid stirring. Using the simulation model, parametric analyses were performed on the 45 mm pump-end bearings to investigate the sensitivity of bearing characteristics to contact friction, axial preload, coolant flow rate, coolant inlet temperature and quality, heat transfer coefficients, outer race clearance and misalignment, and the effects of thermally isolating the outer race from the isolator.

  2. A History of Space Shuttle Main Engine (SSME) Redline Limits Management

    NASA Technical Reports Server (NTRS)

    Arnold, Thomas M.

    2011-01-01

    The Space Shuttle Main Engine (SSME) has several "redlines", which are operational limits designated to preclude a catastrophic shutdown of the SSME. The Space Shuttle Orbiter utilizes a combination of hardware and software to enable or disable the automated redline shutdown capability. The Space Shuttle is launched with the automated SSME redline limits enabled, but there are many scenarios which may result in the manual disabling of the software by the onboard crew. The operational philosophy for manually enabling and disabling the redline limits software has evolved continuously throughout the history of the Space Shuttle Program, due to events such as SSME hardware changes and updates to Space Shuttle contingency abort software. In this paper, the evolution of SSME redline limits management will be fully reviewed, including the operational scenarios which call for manual intervention, and the events that triggered changes to the philosophy. Following this review, improvements to the management of redline limits for future spacecraft will be proposed.

  3. Range safety signal attenuation by the Space Shuttle main engine exhaust plumes

    NASA Technical Reports Server (NTRS)

    Pearce, B. E.

    1983-01-01

    An analysis of attenuation of the range safety signal at 416.5 MHz observed after SRB separation and ending at hand over to Bermuda, during which transmission must pass through the LOX/H2 propelled main engine exhaust plumes, is summarized. Absorption by free electrons in the exhaust plume can account for the nearly constant magnitude of the observed attenuation during this period; it does not explain the short term transient increases that occur at one or more times during this portion of the flight. It is necessary to assume that a trace amount (about 0.5 ppm) of easily ionizable impurity must be present in the exhaust flow. Other mechanisms of attenuation, such as scattering by turbulent fluctuations of both free and bound electrons and absorption by water vapor, were examined but found to be inadequate to explain the observations.

  4. Development of a CCTV system for welder training and monitoring of Space Shuttle Main Engine welds

    NASA Technical Reports Server (NTRS)

    Gordon, S. S.; Flanigan, L. A.; Dyer, G. E.

    1987-01-01

    A Weld Operator's Remote Monitoring System (WORMS) for remote viewing of manual and automatic GTA welds has been developed for use in Space Shuttle Main Engine (SSME) manufacturing. This system utilizes fiberoptics to transmit images from a receiving lens to a small closed-circuit television (CCTV) camera. The camera converts the image to an electronic signal, which is sent to a videotape recorder (VTR) and a monitor. The overall intent of this system is to provide a clearer, more detailed view of welds than is available by direct observation. This system has six primary areas of application: (1) welder training; (2) viewing of joint penetration; (3) viewing visually inaccessible welds; (4) quality control and quality assurance; (5) remote joint tracking and adjustment of variables in machine welds; and (6) welding research and development. This paper describes WORMS and how it applies to each application listed.

  5. Signal Detection Techniques for Diagnostic Monitoring of Space Shuttle Main Engine Turbomachinery

    NASA Technical Reports Server (NTRS)

    Coffin, Thomas; Jong, Jen-Yi

    1986-01-01

    An investigation to develop, implement, and evaluate signal analysis techniques for the detection and classification of incipient mechanical failures in turbomachinery is reviewed. A brief description of the Space Shuttle Main Engine (SSME) test/measurement program is presented. Signal analysis techniques available to describe dynamic measurement characteristics are reviewed. Time domain and spectral methods are described, and statistical classification in terms of moments is discussed. Several of these waveform analysis techniques have been implemented on a computer and applied to dynamc signals. A laboratory evaluation of the methods with respect to signal detection capability is described. A unique coherence function (the hyper-coherence) was developed through the course of this investigation, which appears promising as a diagnostic tool. This technique and several other non-linear methods of signal analysis are presented and illustrated by application. Software for application of these techniques has been installed on the signal processing system at the NASA/MSFC Systems Dynamics Laboratory.

  6. Development of a CCTV system for welder training and monitoring of Space Shuttle Main Engine welds

    NASA Technical Reports Server (NTRS)

    Gordon, S. S.; Flanigan, L. A.; Dyer, G. E.

    1987-01-01

    A Weld Operator's Remote Monitoring System (WORMS) for remote viewing of manual and automatic GTA welds has been developed for use in Space Shuttle Main Engine (SSME) manufacturing. This system utilizes fiberoptics to transmit images from a receiving lens to a small closed-circuit television (CCTV) camera. The camera converts the image to an electronic signal, which is sent to a videotape recorder (VTR) and a monitor. The overall intent of this system is to provide a clearer, more detailed view of welds than is available by direct observation. This system has six primary areas of application: (1) welder training; (2) viewing of joint penetration; (3) viewing visually inaccessible welds; (4) quality control and quality assurance; (5) remote joint tracking and adjustment of variables in machine welds; and (6) welding research and development. This paper describes WORMS and how it applies to each application listed.

  7. A neural network-based estimator for the mixture ratio of the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Guo, T. H.; Musgrave, J.

    1992-01-01

    In order to properly utilize the available fuel and oxidizer of a liquid propellant rocket engine, the mixture ratio is closed loop controlled during main stage (65 percent - 109 percent power) operation. However, because of the lack of flight-capable instrumentation for measuring mixture ratio, the value of mixture ratio in the control loop is estimated using available sensor measurements such as the combustion chamber pressure and the volumetric flow, and the temperature and pressure at the exit duct on the low pressure fuel pump. This estimation scheme has two limitations. First, the estimation formula is based on an empirical curve fitting which is accurate only within a narrow operating range. Second, the mixture ratio estimate relies on a few sensor measurements and loss of any of these measurements will make the estimate invalid. In this paper, we propose a neural network-based estimator for the mixture ratio of the Space Shuttle Main Engine. The estimator is an extension of a previously developed neural network based sensor failure detection and recovery algorithm (sensor validation). This neural network uses an auto associative structure which utilizes the redundant information of dissimilar sensors to detect inconsistent measurements. Two approaches have been identified for synthesizing mixture ratio from measurement data using a neural network. The first approach uses an auto associative neural network for sensor validation which is modified to include the mixture ratio as an additional output. The second uses a new network for the mixture ratio estimation in addition to the sensor validation network. Although mixture ratio is not directly measured in flight, it is generally available in simulation and in test bed firing data from facility measurements of fuel and oxidizer volumetric flows. The pros and cons of these two approaches will be discussed in terms of robustness to sensor failures and accuracy of the estimate during typical transients using

  8. Use of probabilistic design methods for NASA applications. [to be used in design phase of Space Transportation Main Engine

    NASA Technical Reports Server (NTRS)

    Safie, Fayssal M.

    1992-01-01

    This paper presents a reliability evaluation process designed to improve the reliability of advanced launch systems. The work performed includes the development of a reliability prediction methodology to be used in the design phase of the Space Transportation Main Engine (STME). This includes prediction techniques which use historical data bases as well as deterministic and probabilistic engineering models for predicting design reliability. In summary, this paper describes a probabilistic design approach for the next-generation liquid rocket engine, the STME.

  9. Dynamic Characteristics and Stability Analysis of Space Shuttle Main Engine Oxygen Pump

    NASA Technical Reports Server (NTRS)

    Gunter, Edgar J.; Branagan, Lyle

    1991-01-01

    The dynamic characteristics of the Space Shuttle high pressure oxygen pump are presented. Experimental data is presented to show the vibration spectrum and response under actual engine operation and also in spin pit testing for balancing. The oxygen pump appears to be operating near a second critical speed and is sensitive to self excited aerodynamic cross coupling forces in the turbine and pump. An analysis is presented to show the improvement in pump stability by the application of turbulent flow seals, preburner seals, and pump shaft cross sectional modifications.

  10. The Effect of Acoustic Disturbances on the Operation of the Space Shuttle Main Engine Fuel Flowmeter

    NASA Technical Reports Server (NTRS)

    Marcu, Bogdan; Szabo, Roland; Dorney, Dan; Zoladz, Tom

    2007-01-01

    The Space Shuttle Main Engine (SSME) uses a turbine fuel flowmeter (FFM) in its Low Pressure Fuel Duct (LPFD) to measure liquid hydrogen flowrates during engine operation. The flowmeter is required to provide accurate and robust measurements of flow rates ranging from 10000 to 18000 GPM in an environment contaminated by duct vibration and duct internal acoustic disturbances. Errors exceeding 0.5% can have a significant impact on engine operation and mission completion. The accuracy of each sensor is monitored during hot-fire engine tests on the ground. Flow meters which do not meet requirements are not flown. Among other parameters, the device is screened for a specific behavior in which a small shift in the flow rate reading is registered during a period in which the actual fuel flow as measured by a facility meter does not change. Such behavior has been observed over the years for specific builds of the FFM and must be avoided or limited in magnitude in flight. Various analyses of the recorded data have been made prior to this report in an effort to understand the cause of the phenomenon; however, no conclusive cause for the shift in the instrument behavior has been found. The present report proposes an explanation of the phenomenon based on interactions between acoustic pressure disturbances in the duct and the wakes produced by the FFM flow straightener. Physical insight into the effects of acoustic plane wave disturbances was obtained using a simple analytical model. Based on that model, a series of three-dimensional unsteady viscous flow computational fluid dynamics (CFD) simulations were performed using the MSFC PHANTOM turbomachinery code. The code was customized to allow the FFM rotor speed to change at every time step according to the instantaneous fluid forces on the rotor, that, in turn, are affected by acoustic plane pressure waves propagating through the device. The results of the simulations show the variation in the rotation rate of the flowmeter

  11. Relation optimization of the starting and main stages of rockets with short-running engine on the external oxidizer

    NASA Astrophysics Data System (ADS)

    Ustinov, L. A.; Zelenkov, P. V.; Kovalev, I. V.

    2016-11-01

    The paper considers an optimal choice of the mass relation of the starting and main stages of the rocket with a short-running engine on the external oxidizer from the point of view of achieving the maximum firing range.

  12. Engineering in High School: Implementing TMMW & TPE.

    ERIC Educational Resources Information Center

    Bordoloi, Kiron C.; Cole, Joseph D.

    1979-01-01

    The success of two engineering and technology-oriented secondary school programs is discussed. Also presented is the Man Made World and the Technology-People-Environment at two suburban high schools. (BB)

  13. Assuring quality in high-consequence engineering

    SciTech Connect

    Hoover, Marcey L.; Kolb, Rachel R.

    2014-03-01

    In high-consequence engineering organizations, such as Sandia, quality assurance may be heavily dependent on staff competency. Competency-dependent quality assurance models are at risk when the environment changes, as it has with increasing attrition rates, budget and schedule cuts, and competing program priorities. Risks in Sandia's competency-dependent culture can be mitigated through changes to hiring, training, and customer engagement approaches to manage people, partners, and products. Sandia's technical quality engineering organization has been able to mitigate corporate-level risks by driving changes that benefit all departments, and in doing so has assured Sandia's commitment to excellence in high-consequence engineering and national service.

  14. MAIN-BELT ASTEROIDS IN THE K2 ENGINEERING FIELD OF VIEW

    SciTech Connect

    Szabó, R.; Sárneczky, K.; Szabó, Gy. M.; Pál, A.; Kiss, Cs. P.; Kiss, L. L.; Csák, B.; Illés, L.; Rácz, G.

    2015-03-15

    Unlike NASA’s original Kepler Discovery Mission, the renewed K2 Mission will target the plane of the Ecliptic, observing each field for approximately 75 days. This will bring new opportunities and challenges, in particular the presence of a large number of main-belt asteroids that will contaminate the photometry. The large pixel size makes K2 data susceptible to the effects of apparent minor planet encounters. Here, we investigate the effects of asteroid encounters on photometric precision using a subsample of the K2 engineering data taken in 2014 February. We show examples of asteroid contamination to facilitate their recognition and distinguish these events from other error sources. We conclude that main-belt asteroids will have considerable effects on K2 photometry of a large number of photometric targets during the Mission that will have to be taken into account. These results will be readily applicable for future space photometric missions applying large-format CCDs, such as TESS and PLATO.

  15. Integrated Design Methodology for Highly Reliable Liquid Rocket Engine

    NASA Astrophysics Data System (ADS)

    Kuratani, Naoshi; Aoki, Hiroshi; Yasui, Masaaki; Kure, Hirotaka; Masuya, Goro

    The Integrated Design Methodology is strongly required at the conceptual design phase to achieve the highly reliable space transportation systems, especially the propulsion systems, not only in Japan but also all over the world in these days. Because in the past some catastrophic failures caused some losses of mission and vehicle (LOM/LOV) at the operational phase, moreover did affect severely the schedule delays and cost overrun at the later development phase. Design methodology for highly reliable liquid rocket engine is being preliminarily established and investigated in this study. The sensitivity analysis is systematically performed to demonstrate the effectiveness of this methodology, and to clarify and especially to focus on the correlation between the combustion chamber, turbopump and main valve as main components. This study describes the essential issues to understand the stated correlations, the need to apply this methodology to the remaining critical failure modes in the whole engine system, and the perspective on the engine development in the future.

  16. From Shuttle Main Engine to the Human Heart: A Presentation to the Federal Lab Consortium for Technology Transfer

    NASA Technical Reports Server (NTRS)

    Fogarty, Jennifer A.

    2010-01-01

    A NASA engineer received a heart transplant performed by Drs. DeBakey and Noon after suffering a serious heart attack. 6 months later that engineer returned to work at NASA determined to use space technology to help people with heart disease. A relationship between NASA and Drs. DeBakey and Noon was formed and the group worked to develop a low cost, low power implantable ventricular assist device (VAD). NASA patented the method to reduce pumping damage to red blood cells and the design of a continuous flow heart pump (#5,678,306 and #5,947,892). The technology and methodology were licensed exclusively to MicroMed Technology, Inc.. In late 1998 MicroMed received international quality and electronic certifications and began clinical trials in Europe. Ventricular assist devices were developed to bridge the gap between heart failure and transplant. Early devices were cumbersome, damaged red blood cells, and increased the risk of developing dangerous blood clots. Application emerged from NASA turbopump technology and computational fluid dynamics analysis capabilities. To develop the high performance required of the Space Shuttle main engines, NASA pushed the state of the art in the technology of turbopump design. NASA supercomputers and computational fluid dynamics software developed for use in the modeling analysis of fuel and oxidizer flow through rocket engines was used in the miniaturization and optimization of a very small heart pump. Approximately 5 million people worldwide suffer from chronic heart failure at a cost of 40 billion dollars In the US, more than 5000 people are on the transplant list and less than 3000 transplants are performed each year due to the lack of donors. The success of ventricular assist devices has led to an application as a therapeutic destination as well as a bridge to transplant. This success has been attributed to smaller size, improved efficiency, and reduced complications such as the formation of blood clots and infection.

  17. Experimental hydrogen-fueled automotive engine design data-base project. Volume 2. Main technical report

    SciTech Connect

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

    1983-05-01

    Operational performance and emissions characteristics of hydrogen-fueled engines are reviewed. The project activities are reviewed including descriptions of the test engine and its components, the test apparatus, experimental techniques, experiments performed and the results obtained. Analyses of other hydrogen engine project data are also presented and compared with the results of the present effort.

  18. Main Engine Prototype Development for 2nd Generation RLV RS-83

    NASA Technical Reports Server (NTRS)

    Vilja, John; Fisher, Mark; Lyles, Garry M. (Technical Monitor)

    2002-01-01

    This presentation reports on the NASA project to develop a prototype for RS-83 engine designed for use on reusable launch vehicles (RLV). Topics covered include: program objectives, overview schedule, organizational chart, integrated systems engineering processes, requirement analysis, catastrophic engine loss, maintainability analysis tools, and prototype design analysis.

  19. Evaluation of space shuttle main engine fluid dynamic frequency response characteristics

    NASA Technical Reports Server (NTRS)

    Gardner, T. G.

    1980-01-01

    In order to determine the POGO stability characteristics of the space shuttle main engine liquid oxygen (LOX) system, the fluid dynamic frequency response functions between elements in the SSME LOX system was evaluated, both analytically and experimentally. For the experimental data evaluation, a software package was written for the Hewlett-Packard 5451C Fourier analyzer. The POGO analysis software is documented and consists of five separate segments. Each segment is stored on the 5451C disc as an individual program and performs its own unique function. Two separate data reduction methods, a signal calibration, coherence or pulser signal based frequency response function blanking, and automatic plotting features are included in the program. The 5451C allows variable parameter transfer from program to program. This feature is used to advantage and requires only minimal user interface during the data reduction process. Experimental results are included and compared with the analytical predictions in order to adjust the general model and arrive at a realistic simulation of the POGO characteristics.

  20. Numerical analysis of flow in the hot gas manifold of the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Owens, S. F.; Mukerjee, T.; Singhal, A. K.; Przekwas, A. J.; Glynn, D. R.; Costes, N. C.

    1986-01-01

    This paper presents a numerical model and results of analyses carried out to characterize the flow through the two duct configuration of the Hot Gas Manifold of the Space Shuttle Main Engine. Three dimensional computations have been performed for a half-scale air test model using a nonorthogonal body-fitted coordinate system. The calculation domain is extended from the inlet of the turnaround duct to the exit of the transfer duct. Three test cases, one for laminar flow and two for turbulent flow, have been considered. For turbulent flows, constant eddy viscosity and the k-epsilon model of turbulence were employed. As expected, laminar flow calculation predicts much larger pressure drop than turbulent flow cases. The turbulent flow results are in good agreement with the available flow-visualization data. This study and experimental data indicate that the two-transfer duct design will significantly improve the flow distribution in the Hot Gas Manifold and thereby enhance the overall performance of the SSME.

  1. Space Shuttle guidance for multiple main engine failures during first stage

    NASA Technical Reports Server (NTRS)

    Sponaugle, Steven J.; Fernandes, Stanley T.

    1987-01-01

    This paper presents contingency abort guidance schemes recently developed for multiple Space Shuttle main engine failures during the first two minutes of flight (first stage). The ascent and entry guidance schemes greatly improve the possibility of the crew and/or the Orbiter surviving a first stage contingency abort. Both guidance schemes were required to meet certain structural and controllability constraints. In addition, the systems were designed with the flexibility to allow for seasonal variations in the atmosphere and wind. The ascent scheme guides the vehicle to a desirable, lofted state at solid rocket booster burnout while reducing the structural loads on the vehicle. After Orbiter separation from the solid rockets and the external tank, the entry scheme guides the Orbiter through one of two possible entries. If the proper altitude/range/velocity conditions have been met, a return-to-launch-site 'Split-S' maneuver may be attempted. Otherwise, a down-range abort to an equilibrium glide and subsequent crew bailout is performed.

  2. A Monte Carlo study of Weibull reliability analysis for space shuttle main engine components

    NASA Technical Reports Server (NTRS)

    Abernethy, K.

    1986-01-01

    The incorporation of a number of additional capabilities into an existing Weibull analysis computer program and the results of Monte Carlo computer simulation study to evaluate the usefulness of the Weibull methods using samples with a very small number of failures and extensive censoring are discussed. Since the censoring mechanism inherent in the Space Shuttle Main Engine (SSME) data is hard to analyze, it was decided to use a random censoring model, generating censoring times from a uniform probability distribution. Some of the statistical techniques and computer programs that are used in the SSME Weibull analysis are described. The methods documented in were supplemented by adding computer calculations of approximate (using iteractive methods) confidence intervals for several parameters of interest. These calculations are based on a likelihood ratio statistic which is asymptotically a chisquared statistic with one degree of freedom. The assumptions built into the computer simulations are described. The simulation program and the techniques used in it are described there also. Simulation results are tabulated for various combinations of Weibull shape parameters and the numbers of failures in the samples.

  3. Investigations on the main engines exhaust of two Boeing 767-3ZR

    NASA Astrophysics Data System (ADS)

    Lechner, Bernhard; Bacher, Michael; Rodler, Johannes; Sturm, Peter J.

    2004-02-01

    The main engines exhaust of two Boeing 767-3ZR(ER) powered by Pratt & Whitney 4060 has been intensively studied using spectroscopic methods like Fourier Transform Infrared Spectroscopy (FTIR) and Differential Optical Absorption Spectroscopy (DOAS). All cockpit data was provided by the operating airline while the thrust level was varied between idle (25% N1) and 70 % N1 where N1 is the maximum number of revolutions of the fan. The investigated gaseous species were carbon dioxide, carbon monoxide, nitrogen oxides (NO and NO2) and some hydrocarbons (C2H4, C2H2, HCOH and unburned kerosene). A comparison to the database of the International Civil Aviation Organization (ICAO) showed much higher emissions of CO and NOx-emissions in the same range. Although these two aircraft were of the same age and maintained by the same operator the emissions differed by a factor of two. Formaldehyde proved to be the most abundant hydrocarbon besides ethane and ethane.

  4. Space Shuttle guidance for multiple main engine failures during first stage

    NASA Technical Reports Server (NTRS)

    Sponaugle, Steven J.; Fernandes, Stanley T.

    1987-01-01

    This paper presents contingency abort guidance schemes recently developed for multiple Space Shuttle main engine failures during the first two minutes of flight (first stage). The ascent and entry guidance schemes greatly improve the possibility of the crew and/or the Orbiter surviving a first stage contingency abort. Both guidance schemes were required to meet certain structural and controllability constraints. In addition, the systems were designed with the flexibility to allow for seasonal variations in the atmosphere and wind. The ascent scheme guides the vehicle to a desirable, lofted state at solid rocket booster burnout while reducing the structural loads on the vehicle. After Orbiter separation from the solid rockets and the external tank, the entry scheme guides the Orbiter through one of two possible entries. If the proper altitude/range/velocity conditions have been met, a return-to-launch-site 'Split-S' maneuver may be attempted. Otherwise, a down-range abort to an equilibrium glide and subsequent crew bailout is performed.

  5. Bright polar mesospheric clouds formed by main engine exhaust from the space shuttle's final launch

    NASA Astrophysics Data System (ADS)

    Stevens, Michael H.; Lossow, Stefan; Fiedler, Jens; Baumgarten, Gerd; Lübken, Franz-Josef; Hallgren, Kristofer; Hartogh, Paul; Randall, Cora E.; Lumpe, Jerry; Bailey, Scott M.; Niciejewski, R.; Meier, R. R.; Plane, John M. C.; Kochenash, Andrew J.; Murtagh, Donal P.; Englert, Christoph R.

    2012-10-01

    The space shuttle launched for the last time on 8 July 2011. As with most shuttle launches, the three main engines injected about 350 t of water vapor between 100 and 115 km off the east coast of the United States during its ascent to orbit. We follow the motion of this exhaust with a variety of satellite and ground-based data sets and find that (1) the shuttle water vapor plume spread out horizontally in all directions over a distance of 3000 to 4000 km in 18 h, (2) a portion of the plume reached northern Europe in 21 h to form polar mesospheric clouds (PMCs) that are brighter than over 99% of all PMCs observed in that region, and (3) the observed altitude dependence of the particle size is reversed with larger particles above smaller particles. We use a one-dimensional cloud formation model initialized with predictions of a plume diffusion model to simulate the unusually bright PMCs. We find that eddy mixing can move the plume water vapor down to the mesopause near 90 km where ice particles can form. If the eddy diffusion coefficient is 400 to 1000 m2/s, the predicted integrated cloud brightness is in agreement with both satellite and ground-based observations of the shuttle PMCs. The propellant mass of the shuttle is about 20% of that from all vehicles launched during the northern 2011 PMC season. We suggest that the brightest PMC population near 70°N is formed by space traffic exhaust.

  6. A New, Highly Improved Two-Cycle Engine

    NASA Technical Reports Server (NTRS)

    Wiesen, Bernard

    2008-01-01

    The figure presents a cross-sectional view of a supercharged, variable-compression, two-cycle, internal-combustion engine that offers significant advantages over prior such engines. The improvements are embodied in a combination of design changes that contribute synergistically to improvements in performance and economy. Although the combination of design changes and the principles underlying them are complex, one of the main effects of the changes on the overall engine design is reduced (relative to prior two-cycle designs) mechanical complexity, which translates directly to reduced manufacturing cost and increased reliability. Other benefits include increases in the efficiency of both scavenging and supercharging. The improvements retain the simplicity and other advantages of two-cycle engines while affording increases in volumetric efficiency and performance across a wide range of operating conditions that, heretofore have been accessible to four-cycle engines but not to conventionally scavenged two-cycle ones, thereby increasing the range of usefulness of the two-cycle engine into all areas now dominated by the four-cycle engine. The design changes and benefits are too numerous to describe here in detail, but it is possible to summarize the major improvements: Reciprocating Shuttle Inlet Valve The entire reciprocating shuttle inlet valve and its operating gear is constructed as a single member. The shuttle valve is actuated in a lost-motion arrangement in which, at the ends of its stroke, projections on the shuttle valve come to rest against abutments at the ends of grooves in a piston skirt. This shuttle-valve design obviates the customary complex valve mechanism, actuated from an engine crankshaft or camshaft, yet it is effective with every type of two-cycle engine, from small high-speed single cylinder model engines, to large low-speed multiple cylinder engines.

  7. Investigations of Atmospheric Forcing During the High Resolution Main Experiment

    DTIC Science & Technology

    2007-11-02

    represents the differentiation operator such that < Pobs = s^obs. r is a time constant, ^slow represents the compass output, and we have again assumed...can be rewritten in the orm <£~ 1 TS + 1 T< Pobs + (18) that we can compute the angles by performing an While both techniques give...many questions re- main unanswered. The large discrepancy between lab - oratory and field conditions does not seem to be attrib- FIG. 17. Two

  8. A study of the effects of disk flexibility on the rotordynamics of the space shuttle main engine turbo-pumps

    NASA Technical Reports Server (NTRS)

    Flowers, George T.

    1989-01-01

    Rotor dynamical analyses are typically performed using rigid disk models. Studies of rotor models in which the effects of disk flexibility were included indicate that is may be an important effect for many systems. This issue is addressed with respect to the Space Shuttle Main Engine high pressure turbo-pumps. Finite element analyses have been performed for a simplified free-free flexible disk rotor model and the modes and frequencies compared to those of a rigid disk model. The simple model was then extended to a more sophisticated HPTOP rotor model and similar results were observed. Equations were developed that are suitable for modifying the current rotordynamical analysis program to account for disk flexibility. Some conclusions are drawn from the results of this work as to the importance of disk flexibility on the HPTOP rotordynamics and some recommendations are given for follow-up research in this area.

  9. Numerical analysis of flow non-uniformity in the hot gas manifold of the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Thoenes, J.; Robertson, S. J.; Ratliff, A. W.; Anderson, P. G.

    1985-01-01

    Three-dimensional viscous flow in a conceptual hot gas manifold (HGM) for the Space Shuttle Main Engine High Pressure Fuel Turbopump (SSME HPFTP) was numerically analyzed. A finite difference scheme was used to solve the Navier-Stokes equations. The exact geometry of the SSME HGM was modeled using boundary fitted curvilinear coordinates and the General Interpolants Method (GIM) code. Slight compressibility of the subsonic flow was modeled using a linearized equation of state with artificial compressibility. A time relaxation method was used to obtain a steady state solution. The feasibility and potential usefulness of computational methods in assisting the design of SSME components which involves the flow of fluids within complex geometrical shapes is demonstrated.

  10. High-pressure fuel injection system for diesel engine

    SciTech Connect

    Hoshi, Y.

    1986-01-21

    This patent describes a high-pressure fuel injection system for a diesel engine. This system consists of: (a) main pumps for injecting fuel each located at one of cylinders of the engine and formed with a fuel injecting port, a discharge valve located in a path connecting the first injected fuel space with the fuel injecting port. The discharge valve is opened when the fuel to be injected reaches a predetermined pressure level. A first injection timing fuel space fluidly connected with the first injected fuel space through a movable shuttle is filled with injection timing fuel, and a plunger varies the volume of the first injection timing fuel space; (b) a metering and distributing pump formed with injection fuel outputs and injection timing fuel outlets corresponding in number to the cylinders of the engine for discharging fuel in timed relation to the rotation of the engine; (c) fuel metering valves for metering fuel flowing into the second injected fuel space and second injection timing fuel space respectively; (d) pipes for fluidly connecting the first injected fuel space and first injection timing fuel space of the main pump for injecting fuel with the injected fuel outlets and injection timing fuel outlets of the metering and distributing pump respectively; and (e) a rocker arm mechanism for driving the plunger of the main pump for injecting fuel in timed relation to the rotation of the engine.

  11. High temperature NASP engine seal development

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Melis, Matthew E.; Orletski, Dirk; Test, Mark G.

    1991-01-01

    Key to the development of advanced hypersonic engines such as those being considered for the National Aerospace Plane (NASP) is the development and evaluation of high temperature, flexible seals that must seal the many feet of gaps between the articulating and stationary engine panels. Recent seal progress made at NASA-Lewis is reviewed in the areas of seal concept maturation, test rig development, and performance tests. A test fixture was built at NASA capable of subjecting candidate 3 ft long seals to engine simulated temperatures (up to 1500 F), pressures (up to 100 psi), and engine wall distortions (up to 0.15 in only 18 in span). Leakage performance test results at high temperatures are presented for an innovative high temperature, flexible ceramic wafer seal. Also described is a joint Pratt and Whitney/NASA planned test program to evaluate thermal performance of a braided rope seal under engine simulated heat flux rates (up to 400 Btu/sq ft s), and supersonic flow conditions. These conditions are produced by subjecting the seal specimen to hydrogen oxygen rocket exhaust that flows tangent to the specimen.

  12. High temperature dynamic engine seal technology development

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Dellacorte, Christopher; Machinchick, Michael; Mutharasan, Rajakkannu; Du, Guang-Wu; Ko, Frank; Sirocky, Paul J.; Miller, Jeffrey H.

    1992-01-01

    Combined cycle ramjet/scramjet engines being designed for advanced hypersonic vehicles, including the National Aerospace Plane (NASP), require innovative high temperature dynamic seals to seal the sliding interfaces of the articulated engine panels. New seals are required that will operate hot (1200 to 2000 F), seal pressures ranging from 0 to 100 psi, remain flexible to accommodate significant sidewall distortions, and resist abrasion over the engine's operational life. This report reviews the recent high temperature durability screening assessments of a new braided rope seal concept, braided of emerging high temperature materials, that shows promise of meeting many of the seal demands of hypersonic engines. The paper presents durability data for: (1) the fundamental seal building blocks, a range of candidate ceramic fiber tows; and for (2) braided rope seal subelements scrubbed under engine simulated sliding, temperature, and preload conditions. Seal material/architecture attributes and limitations are identified through the investigations performed. The paper summarizes the current seal technology development status and presents areas in which future work will be performed.

  13. Implementation of a model based fault detection and diagnosis for actuation faults of the Space Shuttle main engine

    NASA Technical Reports Server (NTRS)

    Duyar, A.; Guo, T.-H.; Merrill, W.; Musgrave, J.

    1992-01-01

    In a previous study, Guo, Merrill and Duyar, 1990, reported a conceptual development of a fault detection and diagnosis system for actuation faults of the space shuttle main engine. This study, which is a continuation of the previous work, implements the developed fault detection and diagnosis scheme for the real time actuation fault diagnosis of the space shuttle main engine. The scheme will be used as an integral part of an intelligent control system demonstration experiment at NASA Lewis. The diagnosis system utilizes a model based method with real time identification and hypothesis testing for actuation, sensor, and performance degradation faults.

  14. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Dan Clark, with KSC Boeing, operates the camera for a 3D digital scan of the actuator on the table. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Dan Clark, with KSC Boeing, operates the camera for a 3D digital scan of the actuator on the table. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  15. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Boeing worker Alden Pitard looks at a 3D digital scan of an actuator. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Boeing worker Alden Pitard looks at a 3D digital scan of an actuator. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  16. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, an actuator is set up on a table for a 3D digital scan. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, an actuator is set up on a table for a 3D digital scan. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  17. Process for forming a long gas turbine engine blade having a main wall with a thin portion near a tip

    SciTech Connect

    Campbell, Christian X; Thomaidis, Dimitrios

    2014-05-13

    A process is provided for forming an airfoil for a gas turbine engine involving: forming a casting of a gas turbine engine airfoil having a main wall and an interior cavity, the main wall having a wall thickness extending from an external surface of the outer wall to the interior cavity, an outer section of the main wall extending from a location between a base and a tip of the airfoil casting to the tip having a wall thickness greater than a final thickness. The process may further involve effecting movement, using a computer system, of a material removal apparatus and the casting relative to one another such that a layer of material is removed from the casting at one or more radial portions along the main wall of the casting.

  18. Quiet Clean Short-haul Experimental Engine (QCSEE) main reduction gears test program

    NASA Technical Reports Server (NTRS)

    Misel, O. W.

    1977-01-01

    Sets of under the wing (UTW) engine reduction gears and sets of over the wing (OTW) engine reduction gears were fabricated for rig testing and subsequent installation in engines. The UTW engine reduction gears which have a ratio of 2.465:1 and a design rating of 9712 kW at 3157 rpm fan speed were operated at up to 105% speed at 60% torque and 100% speed at 125% torque. The OTW engine reduction gears which have a ratio of 2.062:1 and a design rating of 12,615 kW at 3861 rpm fan speed were operated at up to 95% speed at 50% torque and 80% speed at 109% torque. Satisfactory operation was demonstrated at powers up to 12,172 kW, mechanical efficiency up to 99.1% UTW, and a maximum gear pitch line velocity of 112 m/s (22,300 fpm) with a corresponding star gear spherical roller bearing DN of 850,00 OTW. Oil and star gear bearing temperatures, oil churning, heat rejection, and vibratory characteristics were acceptable for engine installation.

  19. Impact of an Engineering Case Study in a High School Pre-Engineering Course

    ERIC Educational Resources Information Center

    Rutz, Eugene; Shafer, Michelle

    2011-01-01

    Students at an all-girls high school who were enrolled in an introduction to engineering course were presented an engineering case study to determine if the case study affected their attitudes toward engineering and their abilities to solve engineering problems. A case study on power plants was implemented during a unit on electrical engineering.…

  20. Impact of an Engineering Case Study in a High School Pre-Engineering Course

    ERIC Educational Resources Information Center

    Rutz, Eugene; Shafer, Michelle

    2011-01-01

    Students at an all-girls high school who were enrolled in an introduction to engineering course were presented an engineering case study to determine if the case study affected their attitudes toward engineering and their abilities to solve engineering problems. A case study on power plants was implemented during a unit on electrical engineering.…

  1. Influence of pre-injection control parameters on main-injection fuel quantity for an electronically controlled double-valve fuel injection system of diesel engine

    NASA Astrophysics Data System (ADS)

    Song, Enzhe; Fan, Liyun; Chen, Chao; Dong, Quan; Ma, Xiuzhen; Bai, Yun

    2013-09-01

    A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment. The accuracy of the model is validated through comparison with experimental data. The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed. In the spill control valve mode, main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time. In the needle control valve mode, main-injection fuel quantity increases with rising multi-injection dwell time; this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths. Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes; the variation in main-injection quantity is in the range of 1 mm3.

  2. Computational fluid dynamics as a design tool for the hot gas manifold of the Space Shuttle Main Engine

    NASA Technical Reports Server (NTRS)

    Ziebarth, J. P.; Barson, S.; Rosen, R.

    1986-01-01

    The paper discusses the application of computational fluid dynamics as a design tool for the Hot Gas Manifold of the Space Shuttle Main Engine. An improved Hot Gas Manifold configuration was arrived at computationally. This configuration was then built and air flow tested. Testing verified this configuration to be a substantial improvement over existing flight designs.

  3. Space Shuttle Orbiter Main Engine Ignition Acoustic Pressure Loads Issue: Recent Actions to Install Wireless Instrumentation on STS-129

    NASA Technical Reports Server (NTRS)

    Wells, Nathan; Studor, George

    2009-01-01

    This slide presentation reviews the development and construction of the wireless acoustic instruments surrounding the space shuttle's main engines in preparation for STS-129. The presentation also includes information on end-of-life processing and the mounting procedure for the devices.

  4. Analysis of space shuttle main engine data using Beacon-based exception analysis for multi-missions

    NASA Technical Reports Server (NTRS)

    Park, H.; Mackey, R.; James, M.; Zak, M.; Kynard, M.; Sebghati, J.; Greene, W.

    2002-01-01

    This paper describes analysis of the Space Shuttle Main Engine (SSME) sensor data using Beacon-based exception analysis for multimissions (BEAM), a new technology developed for sensor analysis and diagnostics in autonomous space systems by the Jet Propulsion Laboratory (JPL).

  5. High Temperature MEMS for Turbine Engine Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.

    2002-01-01

    The presentation will discuss Microelectromechanical Systems (MEMS) research and development activities and technologies being conducted at NASA Glenn Research Center to address the needs of harsh environment applications. The focus will be on silicon carbide based h4EMS for high temperature, high power and high radiation environment as well as high temperature sensor technologies which are made possible by MEMS processing techniques. These technologies can enable new measurements and capabilities for future turbine engines. All the presentation materials are publicly available and have been presented/published before.

  6. EVALUATION OF A LOW FRICTION - HIGH EFFICIENCY ROLLER BEARING ENGINE

    SciTech Connect

    Kolarik, Robert V. II; Shattuck, Charles W.; Copper, Anthony P.

    2009-06-30

    This Low Friction (High Efficiency Roller Bearing) Engine (LFE) report presents the work done by The Timken Company to conduct a technology demonstration of the benefits of replacing hydrodynamic bearings with roller bearings in the crankshaft and camshaft assemblies of an internal combustion engine for the purpose of collecting data sufficient to prove merit. The engines in the present study have been more extensively converted to roller bearings than any previous studies (40 needle roller bearings per engine) to gain understanding of the full potential of application of bearing technology. The project plan called for comparative testing of a production vehicle which was already respected for having demonstrated low engine friction levels with a rollerized version of that engine. Testing was to include industry standard tests for friction, emissions and fuel efficiency conducted on instrumented dynamometers. Additional tests for fuel efficiency, cold start resistance and other measures of performance were to be made in the actual vehicle. Comparative measurements of noise, vibration and harshness (NVH), were planned, although any work to mitigate the suspected higher NVH level in the rollerized engine was beyond the scope of this project. Timken selected the Toyota Avalon with a 3.5L V-6 engine as the test vehicle. In an attempt to minimize cost and fabrication time, a ‘made-from’ approach was proposed in which as many parts as possible would be used or modified from production parts to create the rollerized engine. Timken commissioned its test partner, FEV Engine Technology, to do a feasibility study in which they confirmed that using such an approach was possible to meet the required dimensional restrictions and tolerances. In designing the roller bearing systems for the crank and cam trains, Timken utilized as many production engine parts as possible. The crankshafts were produced from production line forgings, which use Timken steel, modified with special

  7. Space Shuttle main engine. NASA has not evaluated the alternate fuel turbopump costs and benefits. Report to the Administrator of the National Aeronautics and Space Administration

    NASA Astrophysics Data System (ADS)

    1993-10-01

    NASA's plans to develop an alternate high pressure fuel turbopump for the Space Shuttle's main engines were assessed by the General Accounting Office as a part of the evaluation of the Space Shuttle Safety and Obsolescence Upgrade program. The objective was to determine whether NASA has adequately analyzed cost, performance, and benefits that are expected to result from this program in comparison to other alternatives before resuming development of the alternate pump, which was suspended in 1992. The alternate fuel pump is one of five improvements being developed or planned to significantly enhance safety margins of the engines.

  8. Analytical and experimental investigation of rubbing interaction in labyrinth seals for a liquid hydrogen fuel pump. [space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Dolan, F. X.; Kennedy, F. E.; Schulson, E. M.

    1984-01-01

    Cracking of the titanium knife edges on the labyrinth seals of the liquid hydrogen fuel pump in the Space Shuttle main engine is considered. Finite element analysis of the thermal response of the knife edge in sliding contact with the wear ring surface shows that interfacial temperatures can be quite high and they are significantly influenced by the thermal conductivity of the surfaces in rubbing contact. Thermal shock experiments on a test specimen similar to the knife edge geometry demonstrate that cracking of the titanium alloy is possible in a situation involving repeated thermal cycles over a wide temperature range, as might be realized during a rub in the liquid hydrogen fuel pump. High-speed rub interaction tests were conducted using a representative knife edge and seal geometry over a broad range of interaction rates and alternate materials were experimentally evaluated. Plasma-sprayed aluminum-graphite was found to be significantly better than presently used aluminum alloy seals from the standpoint of rub performance. Ion nitriding the titanium alloy knife-edges also improved rub performance compared to the untreated baseline.

  9. Pulse Detonation Engines for High Speed Flight

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.

    2002-01-01

    Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

  10. Configuration evaluation and criteria plan. Volume 2: Evaluation critera plan (preliminary). Space Transportation Main Engine (STME) configuration study

    NASA Technical Reports Server (NTRS)

    Bair, E. K.

    1986-01-01

    The unbiased selection of the Space Transportation Main Engine (STME) configuration requires that the candidate engines be evaluated against a predetermined set of criteria which must be properly weighted to emphasize critical requirements defined prior to the actual evaluation. The evaluation and selection process involves the following functions: (1) determining if a configuration can satisfy basic STME requirements (yes/no); (2) defining the evaluation criteria; (3) selecting the criteria relative importance or weighting; (4) determining the weighting sensitivities; and (5) establishing a baseline for engine evaluation. The criteria weighting and sensitivities are cost related and are based on mission models and vehicle requirements. The evaluation process is used as a coarse screen to determine the candidate engines for the parametric studies and as a fine screen to determine concept(s) for conceptual design. The criteria used for the coarse and fine screen evaluation process is shown. The coarse screen process involves verifying that the candidate engines can meet the yes/no screening requirements and a semi-subjective quantitative evaluation. The fine screen engines have to meet all of the yes/no screening gates and are then subjected to a detailed evaluation or assessment using the quantitative cost evaluation processes. The option exists for re-cycling a concept through the quantitative portion of the screening and allows for some degree of optimization. The basic vehicle is a two stage LOX/HC, LOX/LH2 parallel burn vehicle capable of placing 150,000 lbs in low Earth orbit (LEO).

  11. Tailored Materials for High Efficiency CIDI Engines

    SciTech Connect

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  12. Configuration evaluation and criteria plan. Volume 1: System trades study and design methodology plan (preliminary). Space Transportation Main Engine (STME) configuration study

    NASA Technical Reports Server (NTRS)

    Bair, E. K.

    1986-01-01

    The System Trades Study and Design Methodology Plan is used to conduct trade studies to define the combination of Space Shuttle Main Engine features that will optimize candidate engine configurations. This is accomplished by using vehicle sensitivities and engine parametric data to establish engine chamber pressure and area ratio design points for candidate engine configurations. Engineering analyses are to be conducted to refine and optimize the candidate configurations at their design points. The optimized engine data and characteristics are then evaluated and compared against other candidates being considered. The Evaluation Criteria Plan is then used to compare and rank the optimized engine configurations on the basis of cost.

  13. Space shuttle with common fuel tank for liquid rocket booster and main engines (supertanker space shuttle)

    NASA Technical Reports Server (NTRS)

    Thorpe, Douglas G.

    1991-01-01

    An operation and schedule enhancement is shown that replaces the four-body cluster (Space Shuttle Orbiter (SSO), external tank, and two solid rocket boosters) with a simpler two-body cluster (SSO and liquid rocket booster/external tank). At staging velocity, the booster unit (liquid-fueled booster engines and vehicle support structure) is jettisoned while the remaining SSO and supertank continues on to orbit. The simpler two-bodied cluster reduces the processing and stack time until SSO mate from 57 days (for the solid rocket booster) to 20 days (for the liquid rocket booster). The areas in which liquid booster systems are superior to solid rocket boosters are discussed. Alternative and future generation vehicles are reviewed to reveal greater performance and operations enhancements with more modifications to the current methods of propulsion design philosophy, e.g., combined cycle engines, and concentric propellant tanks.

  14. High/variable mixture ratio O2/H2 engine

    NASA Technical Reports Server (NTRS)

    Adams, A.; Parsley, R. C.

    1988-01-01

    Vehicle/engine analysis studies have identified the High/Dual Mixture Ratio O2/H2 Engine cycle as a leading candidate for an advanced Single Stage to Orbit (SSTO) propulsion system. This cycle is designed to allow operation at a higher than normal O/F ratio of 12 during liftoff and then transition to a more optimum O/F ratio of 6 at altitude. While operation at high mixture ratios lowers specific impulse, the resultant high propellant bulk density and high power density combine to minimize the influence of atmospheric drag and low altitude gravitational forces. Transition to a lower mixture ratio at altitude then provides improved specific impulse relative to a single mixture ratio engine that must select a mixture ratio that is balanced for both low and high altitude operation. This combination of increased altitude specific impulse and high propellant bulk density more than offsets the compromised low altitude performance and results in an overall mission benefit. Two areas of technical concern relative to the execution of this dual mixture ratio cycle concept are addressed. First, actions required to transition from high to low mixture ratio are examined, including an assessment of the main chamber environment as the main chamber mixture ratio passes through stoichiometric. Secondly, two approaches to meet a requirement for high turbine power at high mixture ratio condition are examined. One approach uses high turbine temperature to produce the power and requires cooled turbines. The other approach incorporates an oxidizer-rich preburner to increase turbine work capability via increased turbine mass flow.

  15. Bioblendstocks that Enable High Efficiency Engine Designs

    SciTech Connect

    McCormick, Robert L.; Fioroni, Gina M.; Ratcliff, Matthew A.; Zigler, Bradley T.; Farrell, John

    2016-11-03

    The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat of vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel

  16. Fuels for high-compression engines

    NASA Technical Reports Server (NTRS)

    Sparrow, Stanwood W

    1926-01-01

    From theoretical considerations one would expect an increase in power and thermal efficiency to result from increasing the compression ratio of an internal combustion engine. In reality it is upon the expansion ratio that the power and thermal efficiency depend, but since in conventional engines this is equal to the compression ratio, it is generally understood that a change in one ratio is accompanied by an equal change in the other. Tests over a wide range of compression ratios (extending to ratios as high as 14.1) have shown that ordinarily an increase in power and thermal efficiency is obtained as expected provided serious detonation or preignition does not result from the increase in ratio.

  17. High temperature NASP engine seal development

    NASA Astrophysics Data System (ADS)

    This video details research being conducted at the Lewis Research Center on high temperature engine seal design for the National Aerospace Plane. To maximize the speed, the jets on the NASP extract oxygen from the air rather than carry large liquid fuel tanks; this creates temperatures within the jet of over 5000 F. To prevent these potentially explosive gases from escaping, researchers are developing new technologies for use in the engine seals. Two examples explained are the ceramic wafer seal and the braided ceramic rope seal. Computer simulations and laboratory footage are used to illustrate the workings of these seals. Benefits for other aerospace and industrial applications, as well as for the space shuttle, are explored.

  18. Improvement on Main/backup Controller Switching Device of the Nozzle Throat Area Control System for a Turbofan Aero Engine

    NASA Astrophysics Data System (ADS)

    Li, Jie; Duan, Minghu; Yan, Maode; Li, Gang; Li, Xiaohui

    2014-06-01

    A full authority digital electronic controller (FADEC) equipped with a full authority hydro-mechanical backup controller (FAHMBC) is adopted as the nozzle throat area control system (NTACS) of a turbofan aero engine. In order to ensure the switching reliability of the main/backup controller, the nozzle throat area control switching valve was improved from three-way convex desktop slide valve to six-way convex desktop slide valve. Simulation results show that, if malfunctions of FAEDC occur and abnormal signals are outputted from FADEC, NTACS will be seriously influenced by the main/backup controller switching in several working states, while NTACS will not be influenced by using the improved nozzle throat area control switching valve, thus the controller switching process will become safer and smoother and the working reliability of this turbofan aero engine is improved by the controller switching device improvement.

  19. Sample Delivery and Computer Control Systems for Detecting Leaks in the Main Engines of the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Griffin, Timothy P.; Naylor, Guy R.; Hritz, Richard J.; Barrett, Carolyn A.

    1997-01-01

    The main engines of the Space Shuttle use hydrogen and oxygen as the fuel and oxidant. The explosive and fire hazards associated with these two components pose a serious danger to personnel and equipment. Therefore prior to use the main engines undergo extensive leak tests. Instead of using hazardous gases there tests utilize helium as the tracer element. This results in a need to monitor helium in the ppm level continuously for hours. The major challenge in developing such a low level gas monitor is the sample delivery system. This paper discuss a system developed to meet the requirements while also being mobile. Also shown is the calibration technique, stability, and accuracy results for the system.

  20. Object oriented fault diagnosis system for space shuttle main engine redlines

    NASA Technical Reports Server (NTRS)

    Rogers, John S.; Mohapatra, Saroj Kumar

    1990-01-01

    A great deal of attention has recently been given to Artificial Intelligence research in the area of computer aided diagnostics. Due to the dynamic and complex nature of space shuttle red-line parameters, a research effort is under way to develop a real time diagnostic tool that will employ historical and engineering rulebases as well as a sensor validity checking. The capability of AI software development tools (KEE and G2) will be explored by applying object oriented programming techniques in accomplishing the diagnostic evaluation.

  1. Introducing High School Students and Science Teachers to Chemical Engineering.

    ERIC Educational Resources Information Center

    Bayles, Taryn Melkus; Aguirre, Fernando J.

    1992-01-01

    Describes a summer institute for science teachers and their students in which the main goal was to increase enrollment in engineering and to encourage women and minority groups to increase their representation in the engineering workforce. Includes a description of typical chemical engineering jobs and general instruction in material balances,…

  2. Introducing High School Students and Science Teachers to Chemical Engineering.

    ERIC Educational Resources Information Center

    Bayles, Taryn Melkus; Aguirre, Fernando J.

    1992-01-01

    Describes a summer institute for science teachers and their students in which the main goal was to increase enrollment in engineering and to encourage women and minority groups to increase their representation in the engineering workforce. Includes a description of typical chemical engineering jobs and general instruction in material balances,…

  3. Genetic algorithm to optimize the design of main combustor and gas generator in liquid rocket engines

    NASA Astrophysics Data System (ADS)

    Son, Min; Ko, Sangho; Koo, Jaye

    2014-06-01

    A genetic algorithm was used to develop optimal design methods for the regenerative cooled combustor and fuel-rich gas generator of a liquid rocket engine. For the combustor design, a chemical equilibrium analysis was applied, and the profile was calculated using Rao's method. One-dimensional heat transfer was assumed along the profile, and cooling channels were designed. For the gas-generator design, non-equilibrium properties were derived from a counterflow analysis, and a vaporization model for the fuel droplet was adopted to calculate residence time. Finally, a genetic algorithm was adopted to optimize the designs. The combustor and gas generator were optimally designed for 30-tonf, 75-tonf, and 150-tonf engines. The optimized combustors demonstrated superior design characteristics when compared with previous non-optimized results. Wall temperatures at the nozzle throat were optimized to satisfy the requirement of 800 K, and specific impulses were maximized. In addition, the target turbine power and a burned-gas temperature of 1000 K were obtained from the optimized gas-generator design.

  4. Systems-Level Energy Audit for Main Complex, Construction Engineering Research Laboratory

    DTIC Science & Technology

    2003-08-01

    landscaping, telecommuting , transpor- tation, parking, and workspace environmental control. Appendix A includes highlights of the workshop...potential for Army facilities and its associated economic and environmental impact resulting in the DOD- FEMP program (now superceded by DOE-FEMP...Monthly billing demand for CERL main complex .................................................... 28 15 Impact of lighting retrofit on energy use

  5. Quiet Clean Short-haul Experimental Engine (QCSEE) main reduction gears bearing development program

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The viability of proposed bearing designs to operate at application conditions is described. Heat rejection variables were defined for the test conditions. Results indicate that there is potential for satisfactory operation of spherical roller bearing in the QCSEE main reduction gear application.

  6. Trends in high power laser applications in civil engineering

    NASA Astrophysics Data System (ADS)

    Wignarajah, Sivakumaran; Sugimoto, Kenji; Nagai, Kaori

    2005-03-01

    This paper reviews the research and development efforts made on the use of lasers for material processing in the civil engineering industry. Initial investigations regarding the possibility of using lasers in civil engineering were made in the 1960s and '70s, the target being rock excavation. At that time however, the laser powers available were too small for any practical application utilization. In the 1980's, the technology of laser surface cleaning of historically important structures was developed in Europe. In the early 1990s, techniques of laser surface modification, including glazing and coloring of concrete, roughening of granite stones, carbonization of wood were pursued, mainly in Japan. In the latter part of the decade, techniques of laser decontamination of concrete surfaces in nuclear facilities were developed in many countries, and field tests were caried out in Japan. The rapid advances in development of diode lasers and YAG lasers with high power outputs and efficiencies since the late 1990's have led to a revival of worldwide interest in the use of lasers for material processing in civil engineering. The authors believe that, in the next 10 years or so, the advent of compact high power lasers is likely to lead to increased use of lasers of material processing in the field of civil engineering.

  7. Advanced Development of a Compact 5-15 lbf Lox/Methane Thruster for an Integrated Reaction Control and Main Engine Propulsion System

    NASA Technical Reports Server (NTRS)

    Hurlbert, Eric A.; McManamen, John Patrick; Sooknanen, Josh; Studak, Joseph W.

    2011-01-01

    This paper describes the advanced development and testing of a compact 5 to 15 lbf LOX/LCH4 thruster for a pressure-fed integrated main engine and RCS propulsion system to be used on a spacecraft "vertical" test bed (VTB). The ability of the RCS thruster and the main engine to operate off the same propellant supply in zero-g reduces mass and improves mission flexibility. This compact RCS engine incorporates several features to dramatically reduce mass and parts count, to ease manufacturing, and to maintain acceptable performance given that specific impulse (Isp) is not the driver. For example, radial injection holes placed on the chamber body for easier drilling, and high temperature Haynes 230 were selected for the chamber over other more expensive options. The valve inlets are rotatable before welding allowing different orientations for vehicle integration. In addition, the engine design effort selected a coil-on-plug ignition system which integrates a relay and coil with the plug electrode, and moves some exciter electronics to avionics driver board. The engine injector design has small dribble volumes to target minimum pulse widths of 20 msec. and an efficient minimum impulse bit of less than 0.05 lbf-sec. The propellants, oxygen and methane, were chosen because together they are a non-toxic, Mars-forward, high density, space storable, and high performance propellant combination that is capable of pressure-fed and pump-fed configurations and integration with life support and power subsystems. This paper will present the results of the advanced development testing to date of the RCS thruster and the integration with a vehicle propulsion system.

  8. Strain engineered pyrochlore at high pressure

    DOE PAGES

    Rittman, Dylan R.; Turner, Katlyn M.; Park, Sulgiye; ...

    2017-05-22

    Strain engineering is a promising method for next-generation materials processing techniques. Here, we use mechanical milling and annealing followed by compression in diamond anvil cell to tailor the intrinsic and extrinsic strain in pyrochlore, Dy2Ti2O7 and Dy2Zr2O7. Raman spectroscopy, X-ray pair distribution function analysis, and X-ray diffraction were used to characterize atomic order over short-, medium-, and long-range spatial scales, respectively, under ambient conditions. Raman spectroscopy and X-ray diffraction were further employed to interrogate the material in situ at high pressure. High-pressure behavior is found to depend on the species and concentration of defects in the sample at ambient conditions.more » Overall, we show that defects can be engineered to lower the phase transformation onset pressure by ~50% in the ordered pyrochlore Dy2Ti2O7, and lower the phase transformation completion pressure by ~20% in the disordered pyrochlore Dy2Zr2O7. Lastly, these improvements are achieved without significantly sacrificing mechanical integrity, as characterized by bulk modulus.« less

  9. Engineering the future with America's high school students

    NASA Technical Reports Server (NTRS)

    Farrance, M. A.; Jenner, J. W.

    1993-01-01

    The number of students enrolled in engineering is declining while the need for engineers is increasing. One contributing factor is that most high school students have little or no knowledge about what engineering is, or what engineers do. To teach young students about engineering, engineers need good tools. This paper presents a course of study developed and used by the authors in a junior college course for high school students. Students learned about engineering through independent student projects, in-class problem solving, and use of career information resources. Selected activities from the course can be adapted to teach students about engineering in other settings. Among the most successful techniques were the student research paper assignments, working out a solution to an engineering problem as a class exercise, and the use of technical materials to illustrate engineering concepts and demonstrate 'tools of the trade'.

  10. Adaptation of aeronautical engines to high altitude flying

    NASA Technical Reports Server (NTRS)

    Kutzbach, K

    1923-01-01

    Issues and techniques relative to the adaptation of aircraft engines to high altitude flight are discussed. Covered here are the limits of engine output, modifications and characteristics of high altitude engines, the influence of air density on the proportions of fuel mixtures, methods of varying the proportions of fuel mixtures, the automatic prevention of fuel waste, and the design and application of air pressure regulators to high altitude flying. Summary: 1. Limits of engine output. 2. High altitude engines. 3. Influence of air density on proportions of mixture. 4. Methods of varying proportions of mixture. 5. Automatic prevention of fuel waste. 6. Design and application of air pressure regulators to high altitude flying.

  11. Engineers' register to ensure high standards.

    PubMed

    Millar, Bill

    2008-05-01

    Bill Millar, project director, United Lincolnshire Hospitals, and chairman of IHEEM's Authorising Engineer (AE) Medical Gas Pipeline Systems (MGPS) panel, describes the latest developments in the setting up of the Authorising Engineer MGPS Register.

  12. A sequential turbocharging method for highly-rated truck diesel engines

    SciTech Connect

    Borila, Y.G.

    1986-01-01

    A sequential turbocharging method specifically developed for highly-turbocharged truck diesel engines is presented here together with the first experimental results. The key element of the method is the use of turbochargers of unequal size, with single entry turbines, in combination with a pulse converter. The first engine test showed a significant improvement of engine performance, especially of low-speed torque and response, without the usual compromise on high-speed performance. The main conclusions of the test was that with this sequential turbocharging method, engine performance is very competitive up to a bmep of 16 bar at rated power and 20 bar at peak torque.

  13. 9. General view of engine between cylinders with high pressure ...

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

    9. General view of engine between cylinders with high pressure cylinder on left and low pressure cylinder on right. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

  14. Studies and analyses of the Space Shuttle Main Engine: SSME failure data review, diagnostic survey and SSME diagnostic evaluation

    NASA Technical Reports Server (NTRS)

    Glover, R. C.; Kelley, B. A.; Tischer, A. E.

    1986-01-01

    The results of a review of the Space Shuttle Main Engine (SSME) failure data for the period 1980 through 1983 are presented. The data was collected, evaluated, and ranked according to procedures established during this study. A number of conclusions and recommendations are made based upon this failure data review. The results of a state-of-the-art diagnostic survey are also presented. This survey covered a broad range of diagnostic sensors and techniques and the findings were evaluated for application to the SSME. Finally, a discussion of the initial activities for the on-going SSME diagnostic evaluation is included.

  15. Validation testing of shallow notched round-bar screening test specimens. [for the space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Vroman, G. A.

    1975-01-01

    The capability of shallow-notched, round-bar, tensile specimens for screening critical environments as they affect the material fracture properties of the space shuttle main engine was tested and analyzed. Specimens containing a 0.050-inch-deep circumferential sharp notch were cyclically loaded in a 5000-psi hydrogen environment at temperatures of +70 and -15 F. Replication of test results and a marked change in cyclic life because of temperature variation demonstrated the validity of the specimen type to be utilized for screening tests.

  16. Prediction of a Newbuilding Proce of the Bulk Carriers based on Gross Tonnage GT and Main Engine Power

    NASA Astrophysics Data System (ADS)

    Cepowska, Żaneta; Cepowski, Tomasz

    2017-03-01

    The paper presents mathematical relationships that allow us to forecast the newbuilding price of new bulk carriers, based on data concerning vessels built in 2005-2015. The presented approximations allow us to estimate the price based on a gross tonnage capacity and a main engine power The approximations were developed using linear regression and the theory of artificial neural networks. The presented relations have practical application for estimation of bulk carrier newbuilding price needed in preliminary parametric design of the ship. It follows from the above that the use of artificial neural networks to predict the price of a bulk carrier brings more accurate solutions than linear regression.

  17. Engineered Ceramic Insulators for High Field Magnets

    NASA Astrophysics Data System (ADS)

    Rice, J. A.

    2006-03-01

    High field magnet coils made from brittle A15 superconductors need to be rigidly contained by their support structure but yet be electrically insulated from it. Current insulators (end shoes, pole pieces, spacers, mandrels, etc.) are often made from coated metallic shapes that satisfy the mechanical and thermal requirements but are electrically unreliable. The insulating coating on the metal core too often chips or flakes, causing electrical shorts. Any replacement insulator materials must manage the thermal expansion mismatch to control the stress within the coil enabling the achievement of ultimate magnet performance. A novel ceramic insulator has been developed that eliminates the potential for shorting while maintaining high structural integrity and thermal performance. The insulator composition can be engineered to provide a thermal expansion that matches the coil expansion, minimizing detrimental stress on the superconductor. These ceramic insulators are capable of surviving high temperature heat treatments and are radiation resistant. The material can withstand high mechanical loads generated during magnet operation. These more robust insulators will lower the magnet production costs, which will help enable future devices to be constructed within budgetary restrictions.

  18. Space shuttle main engine controller assembly, phase C-D. [with lagging system design and analysis

    NASA Technical Reports Server (NTRS)

    1973-01-01

    System design and system analysis and simulation are slightly behind schedule, while design verification testing has improved. Input/output circuit design has improved, but digital computer unit (DCU) and mechanical design continue to lag. Part procurement was impacted by delays in printed circuit board, assembly drawing releases. These are the result of problems in generating suitable printed circuit artwork for the very complex and high density multilayer boards.

  19. HSX: Engineering Design and Fabrication of the main Magnet Coils, Vacuum Vessel and Support/Alignment Structure

    NASA Astrophysics Data System (ADS)

    Anderson, F. Simon B.; Anderson, D. T.; Almagri, A. F.; Matthews, P. G.; Probert, P. H.; Shohet, J. L.; Talmadge, J. N.

    1996-11-01

    The HSX device, with a magnetic field consisting of a SINGLE dominant HELICAL component, has a set of 48 twisted main magnetic field coils. Engineering analysis (ANSYS) has resulted in a set of construction and alignment constraints and goals for field accuracy and coil structural strength. Close proximity of the main coil set to the magnetic separatrix imposes space restrictions on the vacuum vessel. Fabrication of the vessel using explosive techniques, and the structural analysis for the stresses in the vacuum chamber will be discussed. Crucial to the integrity of the quasihelical magnetic field is the accurate positioning of the magnet coils and maintenance of the position during operation. The design and construct- ion of the completed support structure for HSX coils will also be presented. *** Work supported by U.S Dept. of Energy Grant DE-FG02-93ER54222

  20. Combinatorial and high-throughput screening approaches for strain engineering.

    PubMed

    Liu, Wenshan; Jiang, Rongrong

    2015-03-01

    Microbes have long been used in the industry to produce valuable biochemicals. Combinatorial engineering approaches, new strain engineering tools derived from inverse metabolic engineering, have started to attract attention in recent years, including genome shuffling, error-prone DNA polymerase, global transcription machinery engineering (gTME), random knockout/overexpression libraries, ribosome engineering, multiplex automated genome engineering (MAGE), customized optimization of metabolic pathways by combinatorial transcriptional engineering (COMPACTER), and library construction of "tunable intergenic regions" (TIGR). Since combinatorial approaches and high-throughput screening methods are fundamentally interconnected, color/fluorescence-based, growth-based, and biosensor-based high-throughput screening methods have been reviewed. We believe that with the help of metabolic engineering tools and new combinatorial approaches, plus effective high-throughput screening methods, researchers will be able to achieve better results on improving microorganism performance under stress or enhancing biochemical yield.

  1. Fiber optic Raman thermometer for Space Shuttle main engine preburner profiling

    NASA Technical Reports Server (NTRS)

    Shirley, J. A.

    1985-01-01

    The feasibility of combustion gas temperature measurements in the SSME fuel preburner using nonintrusive optical diagnostics was investigated. Temperature profiles are desired in the high pressure, hydrogen-rich preburner stream to evaluate designs to alleviate thermal stressing of the fuel pump turbine blades. Considering the preburner operating conditions and optical access restrictions, a spontaneous Raman backscattering system, implemented with optical fibers to couple to the combustion device, was selected as the most practical for gas temperature probing. A system is described which employs a remotely-located argon-ion laser to excite the molecular hydrogen Raman spectrum. The laser radiation is conveyed to the combustor through an optical fiber and focused through a window into the chamber by an optical head attached to the combustor. The gas temperature is determined from the distribution of rotational populations represented in the Raman spectrum.

  2. Investigation of the Centaur boost pump overspeed condition at main engine shutdown on the Titan Centaur TC-2 flight

    NASA Technical Reports Server (NTRS)

    Baud, K. W.

    1975-01-01

    An investigation was conducted to evaluate a potential boost pump overspeed condition which could exist on the Titan/Centaur launch vehicle after main engine shut-off. Preliminary analyses indicated that the acceleration imparted to the unloaded boost pump-turbine assembly, caused by purging residual hydrogen peroxide from the turbine supply lines, could result in a pump-turbine overspeed. Previous test experience indicated that turbine damage occurs at speeds in excess of 75,000 rpm. Detailed theoretical analyses, in conjunction with pump tests, were conducted to establish the maximum pump-turbine speed at main engine shut-off. The analyses predicted a maximum speed of 68,000 rpm. Testing showed the pump-turbine speed to be 66,700 rpm in the overspeed condition. Inasmuch as both the analysis and tests showed the overspeed to be sufficiently less than the speed at which damage could occur, it was concluded that no corrective action would be required for the launch vehicle.

  3. High School Student Modeling in the Engineering Design Process

    ERIC Educational Resources Information Center

    Mentzer, Nathan; Huffman, Tanner; Thayer, Hilde

    2014-01-01

    A diverse group of 20 high school students from four states in the US were individually provided with an engineering design challenge. Students chosen were in capstone engineering courses and had taken multiple engineering courses. As students considered the problem and developed a solution, observational data were recorded and artifacts…

  4. High School Student Modeling in the Engineering Design Process

    ERIC Educational Resources Information Center

    Mentzer, Nathan; Huffman, Tanner; Thayer, Hilde

    2014-01-01

    A diverse group of 20 high school students from four states in the US were individually provided with an engineering design challenge. Students chosen were in capstone engineering courses and had taken multiple engineering courses. As students considered the problem and developed a solution, observational data were recorded and artifacts…

  5. Acoustically shielded exhaust system for high thrust jet engines

    NASA Technical Reports Server (NTRS)

    Carey, John P. (Inventor); Lee, Robert (Inventor); Majjigi, Rudramuni K. (Inventor)

    1995-01-01

    A flade exhaust nozzle for a high thrust jet engine is configured to form an acoustic shield around the core engine exhaust flowstream while supplementing engine thrust during all flight conditions, particularly during takeoff. The flade airflow is converted from an annular 360.degree. flowstream to an arcuate flowstream extending around the lower half of the core engine exhaust flowstream so as to suppress exhaust noise directed at the surrounding community.

  6. Space Shuttle Main Engine Quantitative Risk Assessment: Illustrating Modeling of a Complex System with a New QRA Software Package

    NASA Technical Reports Server (NTRS)

    Smart, Christian

    1998-01-01

    During 1997, a team from Hernandez Engineering, MSFC, Rocketdyne, Thiokol, Pratt & Whitney, and USBI completed the first phase of a two year Quantitative Risk Assessment (QRA) of the Space Shuttle. The models for the Shuttle systems were entered and analyzed by a new QRA software package. This system, termed the Quantitative Risk Assessment System(QRAS), was designed by NASA and programmed by the University of Maryland. The software is a groundbreaking PC-based risk assessment package that allows the user to model complex systems in a hierarchical fashion. Features of the software include the ability to easily select quantifications of failure modes, draw Event Sequence Diagrams(ESDs) interactively, perform uncertainty and sensitivity analysis, and document the modeling. This paper illustrates both the approach used in modeling and the particular features of the software package. The software is general and can be used in a QRA of any complex engineered system. The author is the project lead for the modeling of the Space Shuttle Main Engines (SSMEs), and this paper focuses on the modeling completed for the SSMEs during 1997. In particular, the groundrules for the study, the databases used, the way in which ESDs were used to model catastrophic failure of the SSMES, the methods used to quantify the failure rates, and how QRAS was used in the modeling effort are discussed. Groundrules were necessary to limit the scope of such a complex study, especially with regard to a liquid rocket engine such as the SSME, which can be shut down after ignition either on the pad or in flight. The SSME was divided into its constituent components and subsystems. These were ranked on the basis of the possibility of being upgraded and risk of catastrophic failure. Once this was done the Shuttle program Hazard Analysis and Failure Modes and Effects Analysis (FMEA) were used to create a list of potential failure modes to be modeled. The groundrules and other criteria were used to screen

  7. Dualling Thomas: Maine College Helps Students Earn College Credit While in High School

    ERIC Educational Resources Information Center

    MacKenzie, Riley

    2016-01-01

    The Pathways Program allows juniors and seniors in high school who have a high school GPA of 3.0, a demonstrated capacity for college work, and a recommendation of the high school guidance counselor, to pursue their associate degrees at Thomas College in Waterville, Maine, while completing the requirements for their high school diploma at…

  8. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 6: Primary nozzle diffuser analysis

    NASA Technical Reports Server (NTRS)

    Foley, Michael J.

    1989-01-01

    The primary nozzle diffuser routes fuel from the main fuel valve on the Space Shuttle Main Engine (SSME) to the nozzle coolant inlet mainfold, main combustion chamber coolant inlet mainfold, chamber coolant valve, and the augmented spark igniters. The diffuser also includes the fuel system purge check valve connection. A static stress analysis was performed on the diffuser because no detailed analysis was done on this part in the past. Structural concerns were in the area of the welds because approximately 10 percent are in areas inaccessible by X-ray testing devices. Flow dynamics and thermodynamics were not included in the analysis load case. Constant internal pressure at maximum SSME power was used instead. A three-dimensional, finite element method was generated using ANSYS version 4.3A on the Lockheed VAX 11/785 computer to perform the stress computations. IDEAS Supertab on a Sun 3/60 computer was used to create the finite element model. Rocketdyne drawing number RS009156 was used for the model interpretation. The flight diffuser is denoted as -101. A description of the model, boundary conditions/load case, material properties, structural analysis/results, and a summary are included for documentation.

  9. High Acceleration, High Life Cycle, Reusable In-Space Main Engine: 2000-2004

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic includes technologies for the crew exploration vehicle. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.

  10. Studies and analyses of the space shuttle main engine. Failure information propagation model data base and software

    NASA Technical Reports Server (NTRS)

    Tischer, A. E.

    1987-01-01

    The failure information propagation model (FIPM) data base was developed to store and manipulate the large amount of information anticipated for the various Space Shuttle Main Engine (SSME) FIPMs. The organization and structure of the FIPM data base is described, including a summary of the data fields and key attributes associated with each FIPM data file. The menu-driven software developed to facilitate and control the entry, modification, and listing of data base records is also discussed. The transfer of the FIPM data base and software to the NASA Marshall Space Flight Center is described. Complete listings of all of the data base definition commands and software procedures are included in the appendixes.

  11. High Fidelity Simulation of Atomization in Diesel Engine Sprays

    DTIC Science & Technology

    2015-09-01

    ARL-RP-0555 ● SEP 2015 US Army Research Laboratory High Fidelity Simulation of Atomization in Diesel Engine Sprays by L Bravo...ARL-RP-0555 ● SEP 2015 US Army Research Laboratory High Fidelity Simulation of Atomization in Diesel Engine Sprays by L...Simulation of Atomization in Diesel Engine Sprays 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) L Bravo, CB Ivey, D

  12. Vibration, acoustic, and shock design and test criteria for components on the Solid Rocket Boosters (SRB), Lightweight External Tank (LWT), and Space Shuttle Main Engines (SSME)

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The vibration, acoustics, and shock design and test criteria for components and subassemblies on the space shuttle solid rocket booster (SRB), lightweight tank (LWT), and main engines (SSME) are presented. Specifications for transportation, handling, and acceptance testing are also provided.

  13. Building a Framework for Engineering Design Experiences in High School

    ERIC Educational Resources Information Center

    Denson, Cameron D.; Lammi, Matthew

    2014-01-01

    In this article, Denson and Lammi put forth a conceptual framework that will help promote the successful infusion of engineering design experiences into high school settings. When considering a conceptual framework of engineering design in high school settings, it is important to consider the complex issue at hand. For the purposes of this…

  14. Examining Gender Inequality in a High School Engineering Course

    ERIC Educational Resources Information Center

    Riegle-Crumb, Catherine; Moore, Chelsea

    2013-01-01

    This paper examines gender inequality within the context of an upper-level high school engineering course recently offered in Texas. Data was collected from six high schools that serve students from a variety of backgrounds. Among the almost two hundred students who enrolled in this challenge-based engineering course, females constituted a clear…

  15. High efficiency stoichiometric internal combustion engine system

    DOEpatents

    Winsor, Richard Edward; Chase, Scott Allen

    2009-06-02

    A power system including a stoichiometric compression ignition engine in which a roots blower is positioned in the air intake for the engine to control air flow. Air flow is decreased during part power conditions to maintain the air-fuel ratio in the combustion chamber of the engine at stoichiometric, thus enabling the use of inexpensive three-way catalyst to reduce oxides of nitrogen. The roots blower is connected to a motor generator so that when air flow is reduced, electrical energy is stored which is made available either to the roots blower to temporarily increase air flow or to the system electrical load and thus recapture energy that would otherwise be lost in reducing air flow.

  16. Examining Gender Inequality In A High School Engineering Course

    PubMed Central

    Moore, Chelsea

    2014-01-01

    This paper examines gender inequality within the context of an upper-level high school engineering course recently offered in Texas. Data was collected from six high schools that serve students from a variety of backgrounds. Among the almost two hundred students who enrolled in this challenge-based engineering course, females constituted a clear minority, comprising only a total of 14% of students. Quantitative analyses of surveys administered at the beginning of the school year (Fall 2011) revealed statistically significant gender gaps in personal attitudes towards engineering and perceptions of engineering climate. Specifically, we found that compared to males, females reported lower interest in and intrinsic value for engineering, and expressed less confidence in their engineering skills. Additionally, female students felt that the classroom was less inclusive and viewed engineering occupations as less progressive. Gender disparities on all of these measures did not significantly decrease by the end of the school year (Spring 2012). Findings suggest that efforts to increase the representation of women in the engineering pipeline via increasing exposure in secondary education must contend not only with obstacles to recruiting high school girls into engineering courses, but must also work to remedy gender differences in engineering attitudes within the classroom. PMID:25568814

  17. High-Lift Engine Aeroacoustics Technology (HEAT) Test Program Overview

    NASA Technical Reports Server (NTRS)

    Zuniga, Fanny A.; Smith, Brian E.

    1999-01-01

    The NASA High-Speed Research program developed the High-Lift Engine Aeroacoustics Technology (HEAT) program to demonstrate satisfactory interaction between the jet noise suppressor and high-lift system of a High-Speed Civil Transport (HSCT) configuration at takeoff, climb, approach and landing conditions. One scheme for reducing jet exhaust noise generated by an HSCT is the use of a mixer-ejector system which would entrain large quantities of ambient air into the nozzle exhaust flow through secondary inlets in order to cool and slow the jet exhaust before it exits the nozzle. The effectiveness of such a noise suppression device must be evaluated in the presence of an HSCT wing high-lift system before definitive assessments can be made concerning its acoustic performance. In addition, these noise suppressors must provide the required acoustic attenuation while not degrading the thrust efficiency of the propulsion system or the aerodynamic performance of the high-lift devices on the wing. Therefore, the main objective of the HEAT program is to demonstrate these technologies and understand their interactions on a large-scale HSCT model. The HEAT program is a collaborative effort between NASA-Ames, Boeing Commercial Airplane Group, Douglas Aircraft Corp., Lockheed-Georgia, General Electric and NASA - Lewis. The suppressor nozzles used in the tests were Generation 1 2-D mixer-ejector nozzles made by General Electric. The model used was a 13.5%-scale semi-span model of a Boeing Reference H configuration.

  18. LED light engine concept with ultra-high scalable luminance

    NASA Astrophysics Data System (ADS)

    Hoelen, Christoph; de Boer, Dick; Bruls, Dominique; van der Eyden, Joost; Koole, Rolf; Li, Yun; Mirsadeghi, Mo; Vanbroekhoven, Vincent; Van den Bergh, John-John; Van de Voorde, Patrick

    2016-03-01

    Although LEDs have been introduced successfully in many general lighting applications during the past decade, high brightness light source applications are still suffering from the limited luminance of LEDs. High power LEDs are generally limited in luminance to ca 100 Mnit (108 lm/m2sr) or less, while dedicated devices for projection may achieve luminance values up to ca 300 Mnit with phosphor converted green. In particular for high luminous flux applications with limited étendue, like in front projection systems, only very modest luminous flux values in the beam can be achieved with LEDs compared to systems based on discharge lamps. In this paper we introduce a light engine concept based on a light converter rod pumped with blue LEDs that breaks through the étendue and brightness limits of LEDs, enabling LED light source luminance values that are more than 4 times higher than what can be achieved with LEDs so far. In LED front projection systems, green LEDs are the main limiting factor. With our green light emitting modules, peak luminance values well above 1.2 Gnit have been achieved, enabling doubling of the screen brightness of LED based DLP projection systems, and even more when this technology is applied to other colors as well. This light source concept, introduced as the ColorSpark High Lumen Density (HLD) LED technology, enables a breakthrough in the performance of LED-based light engines not only for projection, where >2700 ANSI lm was demonstrated, but for a wide variety of high brightness applications.

  19. High Pressure Reverse Flow APS Engine

    NASA Technical Reports Server (NTRS)

    Senneff, J. M.

    1972-01-01

    A design and test demonstration effort was undertaken to evaluate the concept of the reverse flow engine for the APS engine application. The 1500 lb (6672 N) thrust engine was designed to operate on gaseous hydrogen and gaseous oxygen propellants at a mixture ratio of 4 and to achieve the objective performance of 435 sec (4266 Nsec/kg) specific impulse. Superimposed durability requirements called for a million-cycle capability with 50 hours duration. The program was undertaken as a series of tasks including the initial preliminary design, design of critical test components and finally, the design and demonstration of an altitude engine which could be used interchangeably to examine operating parameters as well as to demonstrate the capability of the concept. The program results are reported with data to indicate that all of the program objectives were met or exceeded within the course of testing on the program. The analysis effort undertaken is also reported in detail and supplemented with test data in some cases where prior definitions could not be made. The results are contained of these analyses as well as the test results conducted throughout the course of the program. Finally, the test data and analytical results were combined to allow recommendations for a flight weight design. This preliminary design effort is also detailed.

  20. Engineering High Assurance Distributed Cyber Physical Systems

    DTIC Science & Technology

    2015-01-15

    interact with the physical world have demonstrated the consequences of not adequately verifying the correctness of the software (such as Therac - 25 ...report02-3.pdf [4] Schmidt, D.C. "Guest Editor’s Introduction: Model-Driven Engineering," IEEE Computer 39 (2), pp. 25 -31, February, 2006. [5

  1. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers look down from spaces allotted for the main engines as the rear body flap is lifted for installation on the orbiter Discovery. The body flap, which is temporarily under protective covering, attaches below the main engines.

    NASA Image and Video Library

    2003-09-23

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers look down from spaces allotted for the main engines as the rear body flap is lifted for installation on the orbiter Discovery. The body flap, which is temporarily under protective covering, attaches below the main engines.

  2. Knocking at the College Door: Projections of High School Graduates. Maine

    ERIC Educational Resources Information Center

    Western Interstate Commission for Higher Education, 2013

    2013-01-01

    National and regional trends mask important variation among states in the supply of high school graduates. This profile provides brief indicators for Maine related to: current levels of educational attainment, projections of high school graduates into the future, and two common barriers to student access and success--insufficient academic…

  3. Optical spectroscopy and photometry of main-belt asteroids with a high orbital inclination

    NASA Astrophysics Data System (ADS)

    Iwai, Aya; Itoh, Yoichi; Terai, Tsuyoshi; Gupta, Ranjan; Sen, Asoke; Takahashi, Jun

    2017-02-01

    We carried out low-resolution optical spectroscopy of 51 main-belt asteroids, most of which have highly-inclined orbits. They are selected from D-type candidates in the SDSS-MOC 4 catalog. Using the University of Hawaii 2.2 m telescope and the Inter-University Centre for Astronomy and Astrophysics 2 m telescope in India, we determined the spectral types of 38 asteroids. Among them, eight asteroids were classified as D-type asteroids. Fractions of D-type asteroids are 3.0+/-1.1 for low orbital inclination main-belt asteroids and 7.3+/-2.0 for high orbital inclination main-belt asteroids. The results of our study indicate that some D-type asteroids were formed within the ecliptic region between the main belt and Jupiter, and were then perturbed by Jupiter.

  4. La Vida Robot - High School Engineering Program Combats Engineering Brain Drain

    ScienceCinema

    Cameron, Allan; Fredi, Lajvardi

    2016-07-12

    Carl Hayden High School has built an impressive reputation with its robotics club. At a time when interest in science, math and engineering is declining, the Falcon Robotics club has young people fired up about engineering. Their program in underwater robots (MATE) and FIRST robotics is becoming a national model, not for building robots, but for building engineers. Teachers Fredi Lajvardi and Allan Cameron will present their story (How kids 'from the mean streets of Phoenix took on the best from M.I.T. in the national underwater bot championship' - Wired Magazine, April 2005) and how every student needs the opportunity to 'do real engineering.'

  5. EngineSim: Turbojet Engine Simulator Adapted for High School Classroom Use

    NASA Technical Reports Server (NTRS)

    Petersen, Ruth A.

    2001-01-01

    EngineSim is an interactive educational computer program that allows users to explore the effect of engine operation on total aircraft performance. The software is supported by a basic propulsion web site called the Beginner's Guide to Propulsion, which includes educator-created, web-based activities for the classroom use of EngineSim. In addition, educators can schedule videoconferencing workshops in which EngineSim's creator demonstrates the software and discusses its use in the educational setting. This software is a product of NASA Glenn Research Center's Learning Technologies Project, an educational outreach initiative within the High Performance Computing and Communications Program.

  6. La Vida Robot - High School Engineering Program Combats Engineering Brain Drain

    SciTech Connect

    Cameron, Allan; Lajvardi, Fredi

    2006-03-15

    Carl Hayden High School has built an impressive reputation with its robotics club. At a time when interest in science, math and engineering is declining, the Falcon Robotics club has young people fired up about engineering. Their program in underwater robots (MATE) and FIRST robotics is becoming a national model, not for building robots, but for building engineers. Teachers Fredi Lajvardi and Allan Cameron will present their story (How kids 'from the mean streets of Phoenix took on the best from M.I.T. in the national underwater bot championship' - Wired Magazine, April 2005) and how every student needs the opportunity to 'do real engineering.'

  7. New England Regional Coastal Engineering Conference (1st) Held at Rockport, Maine n 30 October-1 November 1984.

    DTIC Science & Technology

    1985-10-01

    for the Environmental Protection Agency is a good example. We’re monitoring the construction of waste water treatments plants under our grants...Vorosmarty of Altered Tidal Hydrology on Coastal Nutrient UNH Cycling 9:10 Mr. Andrews Tolman Ground Water Impacts of Rising Sea Level and Maine Geological...developing tidal power. We take a look at the high water shot and compare it with the low water shot and think of how much energy it would take to pump that

  8. Using hypermedia to develop an intelligent tutorial/diagnostic system for the Space Shuttle Main Engine Controller Lab

    NASA Technical Reports Server (NTRS)

    Oreilly, Daniel; Williams, Robert; Yarborough, Kevin

    1988-01-01

    This is a tutorial/diagnostic system for training personnel in the use of the Space Shuttle Main Engine Controller (SSMEC) Simulation Lab. It also provides a diagnostic capable of isolating lab failures at least to the major lab component. The system was implemented using Hypercard, which is an program of hypermedia running on Apple Macintosh computers. Hypercard proved to be a viable platform for the development and use of sophisticated tutorial systems and moderately capable diagnostic systems. This tutorial/diagnostic system uses the basic Hypercard tools to provide the tutorial. The diagnostic part of the system uses a simple interpreter written in the Hypercard language (Hypertalk) to implement the backward chaining rule based logic commonly found in diagnostic systems using Prolog. Some of the advantages of Hypercard in developing this type of system include sophisticated graphics, animation, sound and voice capabilities, its ability as a hypermedia tool, and its ability to include digitized pictures. The major disadvantage is the slow execution time for evaluation of rules (due to the interpretive processing of the language). Other disadvantages include the limitation on the size of the cards, that color is not supported, that it does not support grey scale graphics, and its lack of selectable fonts for text fields.

  9. Biologically inspired highly efficient buoyancy engine

    NASA Astrophysics Data System (ADS)

    Akle, Barbar; Habchi, Wassim; Abdelnour, Rita; Blottman, John, III; Leo, Donald

    2012-04-01

    Undersea distributed networked sensor systems require a miniaturization of platforms and a means of both spatial and temporal persistence. One aspect of this system is the necessity to modulate sensor depth for optimal positioning and station-keeping. Current approaches involve pneumatic bladders or electrolysis; both require mechanical subsystems and consume significant power. These are not suitable for the miniaturization of sensor platforms. Presented in this study is a novel biologically inspired method that relies on ionic motion and osmotic pressures to displace a volume of water from the ocean into and out of the proposed buoyancy engine. At a constant device volume, the displaced water will alter buoyancy leading to either sinking or floating. The engine is composed of an enclosure sided on the ocean's end by a Nafion ionomer and by a flexible membrane separating the water from a gas enclosure. Two electrodes are placed one inside the enclosure and the other attached to the engine on the outside. The semi-permeable membrane Nafion allows water motion in and out of the enclosure while blocking anions from being transferred. The two electrodes generate local concentration changes of ions upon the application of an electrical field; these changes lead to osmotic pressures and hence the transfer of water through the semi-permeable membrane. Some aquatic organisms such as pelagic crustacean perform this buoyancy control using an exchange of ions through their tissue to modulate its density relative to the ambient sea water. In this paper, the authors provide an experimental proof of concept of this buoyancy engine. The efficiency of changing the engine's buoyancy is calculated and optimized as a function of electrode surface area. For example electrodes made of a 3mm diameter Ag/AgCl proved to transfer approximately 4mm3 of water consuming 4 Joules of electrical energy. The speed of displacement is optimized as a function of the surface area of the Nafion

  10. Coal-fueled high-speed diesel engine development

    SciTech Connect

    Kakwani, R. M.; Winsor, R. E.; Ryan, III, T. W.; Schwalb, J. A.; Wahiduzzaman, S.; Wilson, Jr., R. P.

    1991-11-01

    The objectives of this program are to study combustion feasibility by running Series 149 engine tests at high speeds with a fuel injection and combustion system designed for coal-water-slurry (CWS). The following criteria will be used to judge feasibility: (1) engine operation for sustained periods over the load range at speeds from 600 to 1900 rpm. The 149 engine for mine-haul trucks has a rated speed of 1900 rpm; (2) reasonable fuel economy and coal burnout rate; (3) reasonable cost of the engine design concept and CWS fuel compared to future oil prices.

  11. High temperature NASP engine seals: A technology review

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Dellacorte, Christopher; Tong, Mike

    1991-01-01

    Progress in developing advanced high temperature engine seal concepts and related sealing technologies for advanced hypersonic engines are reviewed. Design attributes and issues requiring further development for both the ceramic wafer seal and the braided ceramic rope seal are examined. Leakage data are presented for these seals for engine simulated pressure and temperature conditions and compared to a target leakage limit. Basic elements of leakage flow models to predict leakage rates for each of these seals over the wide range of pressure and temperature conditions anticipated in the engine are also presented.

  12. Transcriptional Engineering of Microalgae: Prospects for High-Value Chemicals.

    PubMed

    Bajhaiya, Amit K; Ziehe Moreira, Javiera; Pittman, Jon K

    2017-02-01

    Microalgae are diverse microorganisms that are of interest as novel sources of metabolites for various industrial, nutritional, and pharmaceutical applications. Recent studies have demonstrated transcriptional engineering of some metabolic pathways. We propose here that transcriptional engineering could be a viable means to manipulate the biosynthesis of specific high-value metabolic products.

  13. Method of sealing a high performance automotive engine and engine assembly

    SciTech Connect

    Rosenquist, G.A.

    1994-01-04

    A method of sealing a high performance internal combustion engine with a head gasket having a fire ring comprising providing a groove in the head or block generally concentric with each said combustion opening, each groove having a land area and a generally vertical wall, and positioning the gasket on the block so that when the head is torqued down, each groove receives a fire ring and compresses the wire ring thereof to provide a primary seal therewith at the land area, the wall engages the armor of the fire ring to form a secondary seal, and the head and block clamping surfaces engage the armor to clamp the armor. The head gasket has a main body of a first thickness including a central core and facing layers laminated to the core, and defines a plurality of combustion openings. A fire ring is disposed and secured in each combustion opening, each fire ring comprising a generally U-shaped armor having a pair of legs overlying and underlying the main body adjacent a combustion opening and a central body connecting the legs and ensheathing a wire ring for providing a combustion seal. In use, the combustion seal provides a labyrinth seal against the spaced surfaces of the groove and against a corner defined by the groove. 6 figs.

  14. LEADER - An integrated engine behavior and design analyses based real-time fault diagnostic expert system for Space Shuttle Main Engine (SSME)

    NASA Technical Reports Server (NTRS)

    Gupta, U. K.; Ali, M.

    1989-01-01

    The LEADER expert system has been developed for automatic learning tasks encompassing real-time detection, identification, verification, and correction of anomalous propulsion system operations, using a set of sensors to monitor engine component performance to ascertain anomalies in engine dynamics and behavior. Two diagnostic approaches are embodied in LEADER's architecture: (1) learning and identifying engine behavior patterns to generate novel hypotheses about possible abnormalities, and (2) the direction of engine sensor data processing to perform resoning based on engine design and functional knowledge, as well as the principles of the relevant mechanics and physics.

  15. LEADER - An integrated engine behavior and design analyses based real-time fault diagnostic expert system for Space Shuttle Main Engine (SSME)

    NASA Technical Reports Server (NTRS)

    Gupta, U. K.; Ali, M.

    1989-01-01

    The LEADER expert system has been developed for automatic learning tasks encompassing real-time detection, identification, verification, and correction of anomalous propulsion system operations, using a set of sensors to monitor engine component performance to ascertain anomalies in engine dynamics and behavior. Two diagnostic approaches are embodied in LEADER's architecture: (1) learning and identifying engine behavior patterns to generate novel hypotheses about possible abnormalities, and (2) the direction of engine sensor data processing to perform resoning based on engine design and functional knowledge, as well as the principles of the relevant mechanics and physics.

  16. STUDY ON ASSOCIATE ENGINEERS IN CIVIL ENGINEERING UNDER MODERNIZATION IN JAPAN: CASE STUDY ABOUT GRADUATES FROM THE FIFTH HIGH SCHOOL AND KUMAMOTO HIGHER TECHNICAL SCHOOL

    NASA Astrophysics Data System (ADS)

    Yamanaka, Takafumi; Tanaka, Naoto; Hoshino, Yuji; Honda, Yasuhiro

    The Faculty of Engineering of The Fifth High School and Kumamoto Higher Technical School are the predecessor to The Faculty of Engineering of Kumamoto University. These were the technical schools established in 1897 and 1906 of the Meiji era. The students in these schools were taught high technical knowledge and given the degree "the associate engineer." The first, these schools were ranked among the civil engineering and the ratio of the associate engineers were showed. The second, the course and the office of the graduates from these schools were constructed of database and the main office was showed the local government. The last, the graduates employed in there were extracted from database and analyzed the employment situation. Finally, the roles of them were deliberated in civil engineering under modernization in Japan.

  17. Thrust reverser for high bypass turbofan engine

    SciTech Connect

    Matta, R.K.; Bhutiani, P.K.

    1990-05-08

    This patent describes a thrust reverser for a gas turbine engine of the type which includes an outer wall spaced from the center body of a core engine to define a bypass duct therebetween. The thrust reverser comprising: circumferentially displaced blocker doors, each of the doors being movable between a normal position generally aligned with the outer wall and a thrust reversing position extending transversely of the bypass duct for blocking the exhaust of air through the bypass duct and directing the air through an opening in the outer wall for thrust reversal; each of the blocker doors being of lightweight construction and including a pit in the inner surface thereof in the normal position; means for covering the pit during normal flow of air through the bypass duct to reduce the pressure drop in the bypass duct and to reduce noise. The covering means including a pit cover hingedly mounted at one end thereof on the blocker door and means of biasing the pit cover away from the blocker door to a position providing smooth flow of air through the bypass duct during normal operation.

  18. Detecting W/Z pairs and Higgs at high energy pp colliders: Main experimental issues

    SciTech Connect

    Alverson, G.; Bengtsson, H.U.; Hauptman, J.; Hedin, D.; Herrero, M.J.; Wang, E.; Linn, S.; Young, C.; Milliken, B.; Paige, F.

    1987-03-01

    The main detection issues implied by the search for W and Z/sup 0/ pairs and Higgs in a high energy pp collider context are discussed here. It includes: precise electron identification, missing energy measurement, multilepton recognition, sophisticated jet pattern recognition, and pile-up. The study uses, as much as possible, a ''realistic simulation of life.''

  19. Challenges Faced by Maine School Districts in Providing High Quality Public Education. Research Brief

    ERIC Educational Resources Information Center

    Silvernail, David L.; Linet, Sarah R.

    2014-01-01

    The goal of this study was to: (1) identify challenges faced by Maine school districts in providing high quality public education; (2) describe the magnitude of the challenges; and (3) identify areas where school districts were experiencing some success in meeting these challenges. The School Districts Challenge Survey was distributed online to…

  20. Low pressure high speed Stirling air engine. Final technical report

    SciTech Connect

    Ross, M.A.

    1980-06-16

    The purpose of this project was to design, construct and test a simple, appropriate technology low pressure, high speed, wood-fired Stirling air engine of 100 W output. The final design was a concentric piston/displacer engine of 454 in. bore and 1 in. stroke with a rhombic drive mechanism. The project engine was ultimately completed and tested, using a propane burner for all tests as a matter of convenience. The 100 W aim was exceeded, at atmospheric pressure, over a wide range of engine speed with the maximum power being 112 W at 1150 rpm. A pressure can was constructed to permit pressurization; however the grant funds were running out, and the only pressurized power test attempted was unsuccessful due to seal difficulties. This was a disappointment because numerous tests on the 4 cubic inch engine suggested power would be more than doubled with pressurization at 25 psig. A manifold was designed and constructed to permit operation of the engine over a standard No. 40 pot bellied stove. The engine was run successfully, but at reduced speed and power, over this stove. The project engine started out being rather noisy in operation, but modifications ultimately resulted in a very quiet engine. Various other difficulties and their solutions also are discussed. (LCL)

  1. 60. 1901 STEAM ENGINE HOUSE LOOKING WEST. VISIBLE THROUGH HIGH ...

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

    60. 1901 STEAM ENGINE HOUSE LOOKING WEST. VISIBLE THROUGH HIGH ARCHED PASSAGEWAYS AT LEFT (FORMER WINDOWS) IS 1902 STEAM TURBINE. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

  2. 9. Photocopy of engineering drawing. LC 17 HIGH PRESSURE GAS ...

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

    9. Photocopy of engineering drawing. LC 17 HIGH PRESSURE GAS INSTALLATION: SITE & GRADING PLAN, APRIL 1969. - Cape Canaveral Air Station, Launch Complex 17, Facility 28419, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

  3. A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix F: Data base plots for SSME tests 750-120 through 750-200

    NASA Technical Reports Server (NTRS)

    Coffin, T.

    1986-01-01

    A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is presented. The data base represents dynamic pressure measurements obtained during single engine hot firing tests of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is also included to estimate spectral trends with SSME power level.

  4. Cf6 jet engine performance improvement: high pressure turbine roundness

    SciTech Connect

    Howard, W.D.; Fasching, W.A.

    1982-01-01

    An improved high pressure turbine stator reducing fuel consumption in current CF6-50 turbofan engines was developed. The feasibility of the roundness and clearance response improvements was demonstrated. Application of these improvements will result in a cruise SFC reduction of 0.22 percent for new engines. For high time engines, the improved roundness and response characteristics results in an 0.5 percent reduction in cruise SFC. A basic life capability of the improved HP turbine stator in over 800 simulated flight cycles without any sign of significant distress is shown.

  5. CF6 jet engine performance improvement: High pressure turbine roundness

    NASA Technical Reports Server (NTRS)

    Howard, W. D.; Fasching, W. A.

    1982-01-01

    An improved high pressure turbine stator reducing fuel consumption in current CF6-50 turbofan engines was developed. The feasibility of the roundness and clearance response improvements was demonstrated. Application of these improvements will result in a cruise SFC reduction of 0.22 percent for new engines. For high time engines, the improved roundness and response characteristics results in an 0.5 percent reduction in cruise SFC. A basic life capability of the improved HP turbine stator in over 800 simulated flight cycles without any sign of significant distress is shown.

  6. Engineering of High-Toughness Carbon Nanotubes Hierarchically Laminated Composites

    DTIC Science & Technology

    2012-01-27

    REPORT TYPE Final 3. DATES COVERED (From - To) Jul-10 - Jul-11 4. TITLE AND SUBTITLE Program Title: ENGINEERING OF HIGH-TOUGHNESS CARBON NANOTUBES ...LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON Program Title: ENGINEERING OF HIGH-TOUGHNESS CARBON NANOTUBES ...Ashby plots can be attained (Fig. 2B). 5. New doping method of carbon nanotubes was developed. Funding Profile: (Give the fiscal year funding

  7. High variable mixture ratio oxygen/hydrogen engine

    NASA Technical Reports Server (NTRS)

    Erickson, C. M.; Tu, W. H.; Weiss, A. H.

    1988-01-01

    The ability of an O2/H2 engine to operate over a range of high-propellant mixture ratios was previously shown to be advantageous in single stage to orbit (SSTO) vehicles. The results are presented for the analysis of high-performance engine power cycles operating over propellant mixture ratio ranges of 12 to 6 and 9 to 6. A requirement to throttle up to 60 percent of nominal thrust was superimposed as a typical throttle range to limit vehicle acceleration as propellant is expended. The object of the analysis was to determine areas of concern relative to component and engine operability or potential hazards resulting from the operating requirements and ranges of conditions that derive from the overall engine requirements. The SSTO mission necessitates a high-performance, lightweight engine. Therefore, staged combustion power cycles employing either dual fuel-rich preburners or dual mixed (fuel-rich and oxygen-rich) preburners were examined. Engine mass flow and power balances were made and major component operating ranges were defined. Component size and arrangement were determined through engine layouts for one of the configurations evaluated. Each component is being examined to determine if there are areas of concern with respect to component efficiency, operability, reliability, or hazard. The effects of reducing the maximum chamber pressure were investigated for one of the cycles.

  8. Grain boundary engineering of highly deformable ceramics

    SciTech Connect

    Mecartney, M.L.

    2000-07-01

    Highly deformable ceramics can be created with the addition of intergranular silicate phases. These amorphous intergranular phases can assist in superplastic deformation by relieving stress concentrations and minimizing grain growth if the appropriate intergranular compositions are selected. Examples from 3Y-TZP and 8Y-CSZ ceramics are discussed. The grain boundary chemistry is analyzed by high resolution analytical TEM is found to have a strong influence on the cohesion of the grains both at high temperature and at room temperature. Intergranular phases with a high ionic character and containing large ions with a relatively weak bond strength appear to cause premature failure. In contrast, intergranular phases with a high degree of covalent character and similar or smaller ions than the ceramic and a high ionic bond strength are the best for grain boundary adhesion and prevention of both cavitation at high temperatures and intergranular fracture at room temperature.

  9. Engine panel seals for hypersonic engine applications: High temperature leakage assessments and flow modelling

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Mutharasan, Rajakkannu; Du, Guang-Wu; Miller, Jeffrey H.; Ko, Frank

    1992-01-01

    A critical mechanical system in advanced hypersonic engines is the panel-edge seal system that seals gaps between the articulating horizontal engine panels and the adjacent engine splitter walls. Significant advancements in seal technology are required to meet the extreme demands placed on the seals, including the simultaneous requirements of low leakage, conformable, high temperature, high pressure, sliding operation. In this investigation, the seal concept design and development of two new seal classes that show promise of meeting these demands will be presented. These seals include the ceramic wafer seal and the braided ceramic rope seal. Presented are key elements of leakage flow models for each of these seal types. Flow models such as these help designers to predict performance-robbing parasitic losses past the seals, and estimate purge coolant flow rates. Comparisons are made between measured and predicted leakage rates over a wide range of engine simulated temperatures and pressures, showing good agreement.

  10. Near-infrared spectra of high-albedo outer main-belt asteroids

    SciTech Connect

    Kasuga, Toshihiro; Shirahata, Mai; Usui, Fumihiko; Kuroda, Daisuke; Ootsubo, Takafumi; Okamura, Natsuko; Hasegawa, Sunao

    2015-02-01

    Most outer main-belt asteroids have low albedos because of their carbonaceouslike bodies. However, infrared satellite surveys have revealed that some asteroids have high albedos, which may suggest the presence of unusual surface minerals for those primitive objects. We present new near-infrared (1.1–2.5 μm) spectra of four outer main-belt asteroids with albedos ≥ 0.1. The C-complex asteroids (555) Norma and (2542) Calpurnia are featureless and have (50%–60%) amorphous Mg pyroxenes that might explain the high albedos. Asteroids (701) Oriola (which is a C-complex asteroid) and (2670) Chuvashia (a D/T-type or M-type asteroid) show possible broad absorption bands (1.5–2.1 μm). The feature can be reproduced by either Mg-rich amorphous pyroxene (with 50%–60% and 80%–95% Mg, respectively) or orthopyroxene (crystalline silicate), which might be responsible for the high albedos. No absorption features of water ice (near 1.5 and 2.0 μm) are detected in the objects. We discuss the origin of high albedo components in the outer main-belt asteroids and their physical relations to comets.

  11. High/variable mixture ratio oxygen/hydrogen engines

    NASA Technical Reports Server (NTRS)

    Knuth, William H.; Beveridge, John H.

    1988-01-01

    A LOX/LH2 high/variable mixture ratio booster upper stage is described. The engine has high thrust-weight ratio as a booster and high specific impulse as an upper stage engine. Operation at high mixture ratio utilizes the propellants at high bulk density. The engine may use multiple turbopump-preburners for higher thrust ratings. The engine uses the full flow cycle to obtain minimum turbine inlet temperatures for a given chamber pressure and to avoid interpropellant shaft seals and other single point failure modes. A portion of the liquid hydrogen is used to regeneratively cool the thrust chamber assembly. The warmed hydrogen coolant is then used to drive the fuel boost turbopump. All propellants arrive at the gas-gas injector ready to burn. Shear mixing of the parallel flowing high velocity, low density fuel-rich gases with the high density, low velocity oxidizer-rich gases provides complete combustion with a modest chamber volume. Combustion stability is assured by the injection of the heated fuel-rich gases and the comparatively low volume ratio of the propellants before and after combustion. The high area ratio nozzle skirt is fitted with a low area ratio nozzle skirt insert for optimum low altitude performance. The overall engine characteristics make it a candidate for ALS, Shuttle-C, LRB, and SSTO applications.

  12. Compact and High Thrust Air Turbo Ram Engine

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hiroaki; Kitahara, Kazuki; Inukai, Yasuo

    The Air Turbo Ramjet (ATR) is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds and therefore the ATR is an attractive propulsion system for the wide operation range (e.g. Mach 0 to Mach 4). The ATR can provide a higher specific impulse than a solid fuel rocket engine and a higher thrust per frontal area than a turbojet engine. The major ATR components are the inlet, fan (compressor), turbine, gas generator, combustor and exhaust nozzle. In the ATR, the turbine drive gas is generated by a decomposed liquid or solid fuel gas generator. In order to carry heavier payloads and to attain shorter flight time, the compact and high thrust engine is required. In this study, the ram combustor with the double-staged flameholders and the fan with tandem blade were introduced to shorten the engine length and to increase the fan pressure ratio, respectively. Furthermore, the engine testing was carried out on sea level static condition to confirm the engine component integration technologies for the ATR propulsion system.

  13. Energy efficient engine high-pressure turbine detailed design report

    NASA Technical Reports Server (NTRS)

    Thulin, R. D.; Howe, D. C.; Singer, I. D.

    1982-01-01

    The energy efficient engine high-pressure turbine is a single stage system based on technology advancements in the areas of aerodynamics, structures and materials to achieve high performance, low operating economics and durability commensurate with commercial service requirements. Low loss performance features combined with a low through-flow velocity approach results in a predicted efficiency of 88.8 for a flight propulsion system. Turbine airfoil durability goals are achieved through the use of advanced high-strength and high-temperature capability single crystal materials and effective cooling management. Overall, this design reflects a considerable extension in turbine technology that is applicable to future, energy efficient gas-turbine engines.

  14. Field of High Voltage Engineering at Graz University of Technology

    NASA Astrophysics Data System (ADS)

    Pack, Stephan

    High Voltage Engineering is an important task at the Graz University of Technology since the early 1970s. Additional importance was given by the national decission, to offer this university and research activities for Austria in Graz only. Therfore this paper reports—based on the history—the actual situation of university education and research activities in the field of high voltage engineering and gives impressions on high voltage (HV) and extra high voltage (EHV) test facilities and test examples at the accredited laboratory of this university.

  15. High Take Off Left Main and Abnormal Origin of Right Coronary Artery: A Case Report

    PubMed Central

    Salehi, Negar; Abdi, Seyfollah; Pouraliakba, Hamid Reza; Vakili-Zarch, Anoushiravan

    2013-01-01

    Coronary anomalies are rare congenital disorders with mostly benign course. We report a case of 54-year-old white male who was with stable angina scheduled for coronary angiography. Due to the difficulty of catheterization, patient underwent CT angiography and high take off left main and right coronary arteries were revealed. We conclude that anomalous coronary arteries are important and coronary interventions may be difficult in their presence.

  16. High Pressure Regenerative Turbine Engine: 21st Century Propulsion

    NASA Technical Reports Server (NTRS)

    Lear, W. E.; Laganelli, A. L.; Senick, Paul (Technical Monitor)

    2001-01-01

    A novel semi-closed cycle gas turbine engine was demonstrated and was found to meet the program goals. The proof-of-principle test of the High Pressure Regenerative Turbine Engine produced data that agreed well with models, enabling more confidence in designing future prototypes based on this concept. Emission levels were significantly reduced as predicted as a natural attribute of this power cycle. Engine testing over a portion of the operating range allowed verification of predicted power increases compared to the baseline.

  17. High Stability Engine Control (HISTEC) Flight Test Results

    NASA Technical Reports Server (NTRS)

    Southwick, Robert D.; Gallops, George W.; Kerr, Laura J.; Kielb, Robert P.; Welsh, Mark G.; DeLaat, John C.; Orme, John S.

    1998-01-01

    The High Stability Engine Control (HISTEC) Program, managed and funded by the NASA Lewis Research Center, is a cooperative effort between NASA and Pratt & Whitney (P&W). The program objective is to develop and flight demonstrate an advanced high stability integrated engine control system that uses real-time, measurement-based estimation of inlet pressure distortion to enhance engine stability. Flight testing was performed using the NASA Advanced Controls Technologies for Integrated Vehicles (ACTIVE) F-15 aircraft at the NASA Dryden Flight Research Center. The flight test configuration, details of the research objectives, and the flight test matrix to achieve those objectives are presented. Flight test results are discussed that show the design approach can accurately estimate distortion and perform real-time control actions for engine accommodation.

  18. Creation of a gilded trap by the high economic value of the Maine lobster fishery.

    PubMed

    Steneck, R S; Hughes, T P; Cinner, J E; Adger, W N; Arnold, S N; Berkes, F; Boudreau, S A; Brown, K; Folke, C; Gunderson, L; Olsson, P; Scheffer, M; Stephenson, E; Walker, B; Wilson, J; Worm, B

    2011-10-01

    Unsustainable fishing simplifies food chains and, as with aquaculture, can result in reliance on a few economically valuable species. This lack of diversity may increase risks of ecological and economic disruptions. Centuries of intense fishing have extirpated most apex predators in the Gulf of Maine (United States and Canada), effectively creating an American lobster (Homarus americanus) monoculture. Over the past 20 years, the economic diversity of marine resources harvested in Maine has declined by almost 70%. Today, over 80% of the value of Maine's fish and seafood landings is from highly abundant lobsters. Inflation-corrected income from lobsters in Maine has steadily increased by nearly 400% since 1985. Fisheries managers, policy makers, and fishers view this as a success. However, such lucrative monocultures increase the social and ecological consequences of future declines in lobsters. In southern New England, disease and stresses related to increases in ocean temperature resulted in more than a 70% decline in lobster abundance, prompting managers to propose closing that fishery. A similar collapse in Maine could fundamentally disrupt the social and economic foundation of its coast. We suggest the current success of Maine's lobster fishery is a gilded trap. Gilded traps are a type of social trap in which collective actions resulting from economically attractive opportunities outweigh concerns over associated social and ecological risks or consequences. Large financial gain creates a strong reinforcing feedback that deepens the trap. Avoiding or escaping gilded traps requires managing for increased biological and economic diversity. This is difficult to do prior to a crisis while financial incentives for maintaining the status quo are large. The long-term challenge is to shift fisheries management away from single species toward integrated social-ecological approaches that diversify local ecosystems, societies, and economies.

  19. Aircraft High Bypass Fan Engine Performance

    DTIC Science & Technology

    1994-03-01

    in component efficiencies, combustor design, development of high temperature alloys , and the development of the high bypass fan. The biggest advance...Partially Modified 29.3:1 1.58:1 9.0:1 2900 7029 0.6213 P/M 107 Partially Modified 29.3:1 1.53:1 9.0:1 2700 6660 0.606 F/M 103 Fully Modified 29.3:1 1.53:1

  20. High-Speed Tests of Radial-Engine Cowlings

    NASA Technical Reports Server (NTRS)

    Robinson, Russell G.; Becker, John V.

    1939-01-01

    The drag characteristics of eight radial-engine cowlings have been determined over a wide speed range in the N.A.C.A. 8-foot high-speed wind tunnel. The pressure distribution over all cowlings was measured, to and above the speed of the compressibility burble, as an aid in interpreting the force tests. One-fifth-scale models of radial-engine cowlings on a wing-nacelle combination mere used in the tests.

  1. High-Speed Tests of Conventional Radial-Engine Cowlings

    NASA Technical Reports Server (NTRS)

    Robinson, Russell G; Becker, John V

    1942-01-01

    The drag characteristics of eight radial-engine cowlings have been determined over a wide speed range in the NACA 8-foot high-speed wind tunnel. The pressure distribution over all cowlings was measured, to and above the speed of the compressibility burble, as an aid in interpreting the force tests. One-fifth-scale models of radial-engine cowlings on a wing-nacelle combination were used in the tests.

  2. Dynamic Modeling and Simulation Study for the Galileo Spacecraft Pulsed-Mode Spinup/400 N Main Engine Burn/Spindown Maneuvers

    NASA Technical Reports Server (NTRS)

    Ih, Che-Hang Charles; McMahon, Elihu M.

    1996-01-01

    Two Galileo dynamic models were developed to simulate the spinup/400-N main engine burn/spindown maneuvers for the critical events of Jupiter Orbit Insertion (JOI) and Perijove Raise Maneuver (PRM). The dynamic interaction among the spin thruster pulsing frequency science/magnetometer (SCI/MAG) boom flexible modes, and the propellant slosh modes were studied.

  3. Technicians monitor the positioning of a workstand as it is moved into place around the main engines of the shuttle Endeavour during deservicing at NASA DFRC

    NASA Image and Video Library

    2008-12-02

    Technicians monitor the positioning of a large workstand as it is carefully moved into place around the main engine nozzles of Space Shuttle Endeavour during deservicing and ferry flight preparations at NASA's Dryden Flight Research Center at Edwards Air Force Base.

  4. KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  5. KENNEDY SPACE CENTER, FLA. - Boeing workers get ready to perform a 3D digital scan of the actuator on the table. At left is John Macke, from Boeing, St. Louis. At right is Dan Clark.. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Boeing workers get ready to perform a 3D digital scan of the actuator on the table. At left is John Macke, from Boeing, St. Louis. At right is Dan Clark.. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  6. KENNEDY SPACE CENTER, FLA. - John Macke (standing, center), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, check results after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - John Macke (standing, center), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, check results after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  7. KENNEDY SPACE CENTER, FLA. - John Macke (standing, left), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, look at a monitor after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - John Macke (standing, left), with Boeing St. Louis, Alden Pitard (seated, left) and Dan Clark (right), with KSC Boeing, look at a monitor after 3D digital scanning of actuators in the Orbiter Processing Facility. There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

  8. 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.

  9. High temperature corrosion of engineering alloys

    SciTech Connect

    Lai, G.Y.

    1990-01-01

    This book describes a treatment of all forms of high temperature corrosion problems encountered in industry, especially gas turbine and aerospace; heat treating; mineral and metallurgical processing; ceramic, electronic and glass manufacturing; automotive; pulp and paper; waste incineration; fossil fuel power generation; coal gasification; and nuclear. Materials problems discussed include those due to oxidation, carburization and metal dusting, nitridation, halogen corrosion, sulfidation, ash/salt deposit corrosion, molten salt corrosion, and molten metal corrosion.

  10. 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.

  11. Jet engine powers large, high-temperature wind tunnel

    NASA Technical Reports Server (NTRS)

    Benham, T. F.; Mulliken, S. R.

    1967-01-01

    Wind tunnel for large component testing uses a jet engine with afterburner to provide high temperatures /1200 degrees to 2000 degrees F/ and controlled high velocity gas. This economical wind tunnel can accommodate parts ten feet by ten feet or larger, and is a useful technique for qualitative information.

  12. Ultra High Bypass Ratio Low Noise Engine Study

    NASA Technical Reports Server (NTRS)

    Dalton, W. N., III

    2003-01-01

    A study was conducted to identify engine cycle and technologies needed for a regional aircraft which could be capable of achieving a 10 EPNdB reduction in community noise level relative to current FAR36 Stage 3 limits. The study was directed toward 100-passenger regional aircraft with engine configurations in the 15,000 pound thrust class. The study focused on Ultra High Bypass Ratio (UHBR) cycles due to low exhaust jet velocities and reduced fan tip speeds. The baseline engine for this study employed a gear-driven, 1000 ft/sec tip speed fan and had a cruise bypass ratio of 14:1. A revised engine configuration employing fan and turbine design improvements are predicted to be 9.2 dB below current takeoff limits and 12.8 dB below current approach limits. An economic analysis was also done by estimating Direct Operating Cost (DOC).

  13. Development of an engineering level prediction method for high angle of attack aerodynamics

    NASA Technical Reports Server (NTRS)

    Reisenthel, Patrick H.; Rodman, Laura C.; Nixon, David

    1993-01-01

    The present work is concerned with predicting the unsteady flow considered to be the cause of the structural failure of twin vertical tail aircraft. An engineering tool has been produced for high angle of attack aerodynamics using the simplest physical models. The main innovation behind this work is its emphasis on the modeling of two key aspects of the dominant physics associated with high angle-of-attack airflows, namely unsteady separation and vortex breakdown.

  14. Feature of high flux engineering test reactor and its role in nuclear power development

    SciTech Connect

    Guangquan, L.

    1988-01-01

    The High Flux Engineering Test Reactor (HFETR) designed and built by China own efforts reached to its initial criticality on Dec. 27, 1979, and then achieved high power operation on Dec. 16, 1980. Until Nov. 11, 1986, the reactor had been operated for thirteen cycles. The paper presents briefly main feature of HFETR and its utilization during past years. The paper also deals with its role in nuclear power development. Finally, author gives his opinion on comprehensive utilization of HFETR.

  15. High-technology ceramics for Japanese heat engines

    SciTech Connect

    Kamo, R.

    1984-01-01

    Japan's new ceramic age is providing the impetus for developing new materials for heat engine applications. A strategy developed by the Japanese Ministry of International Trade and Industry (MITI), universities, and industry has led to developments that make Japan competitive. The author describes the functions and levels of effort as well as the funding arrangements for two basic MITI projects: Moonlight Project and Industrial Base Technology Development Project. He concludes that a solution of the problems associated with ceramic heat engines will lead to a low-cost, waterless and oilless engine with high thermal efficiency. US technology is currently superior except for the high temperature-high strength ceramic materials. Three government research laboratories in Nagoya, Osaka, and Kyushu also work together with private and industrial laboratories. 17 references, 7 figures, 6 tables.

  16. The vending and à la carte policy intervention in Maine public high schools.

    PubMed

    Davee, Anne-Marie; Blum, Janet E Whatley; Devore, Rachel L; Beaudoin, Christina M; Kaley, Lori A; Leiter, Janet L; Wigand, Debra A

    2005-11-01

    A healthy school nutrition environment may be important for decreasing childhood overweight. This article describes a project to make healthier snacks and beverages available in vending machines and à la carte programs in Maine public high schools. Seven public high schools in Maine volunteered to participate in this project. Four schools made changes to the nutrition environment, and three schools that served as controls did not. The nutrition guidelines were to offer only low-fat (not more than 30% of total calories from fat) and low-sugar (not more than 35% by weight of sugar) items in vending machines and à la carte programs. Strategies to implement the project included early communications with school officials, monetary stipends for participation, identification of a school liaison, and a committee at each school to promote the healthy changes. Baseline nutrient content and sales of all competitive foods and beverages were assessed to develop the guidelines for changes in the four schools. Student volunteers at all seven schools were measured for height, weight, diet quality, and physical activity level to assess the impact of the change to the nutrition environment. Baseline measures were taken in the spring semester of 2004. Nutrition changes were made to the à la carte programs and vending machines in the four intervention schools at the start of the fall semester of 2004. Follow-up nutrition assessment and student data collection occurred in the spring semester of 2005. Healthy changes in vending machines were more easily achieved than those made in the à la carte programs. Technical assistance and ongoing support were essential for successful implementation of this intervention. It is possible to improve the nutrition environment of Maine public high schools. Stakeholder support is essential to sustain healthy changes.

  17. Hamiltonian Engineering for High Fidelity Quantum Operations

    NASA Astrophysics Data System (ADS)

    Ribeiro, Hugo; Baksic, Alexandre; Clerk, Aashish

    High-fidelity gates and operations are crucial to almost every aspect of quantum information processing. In recent experiments, fidelity is mostly limited by unwanted couplings with states living out of the logical subspace. This results in both leakage and phase errors. Here, we present a general method to deal simultaneously with both these issues and improve the fidelity of quantum gates and operations. Our method is applicable to a wide variety of systems. As an example, we can correct gates for superconducting qubits, improve coherent state transfer between a single NV centre electronic spin and a single nitrogen nuclear spin, improve control over a nuclear spin ensemble, etc. Our method is intimately linked to the Magnus expansion. By modifying the Magnus expansion of an initially given Hamiltonian Hi, we find analytically additional control Hamiltonians Hctrl such that Hi +Hctrl leads to the desired gate while minimizing both leakage and phase errors.

  18. Facet engineering of high power single emitters

    NASA Astrophysics Data System (ADS)

    Yanson, Dan; Levi, Moshe; Shamay, Moshe; Tesler, Renana; Rappaport, Noam; Don, Yaroslav; Karni, Yoram; Schnitzer, Itzhak; Sicron, Noam; Shusterman, Sergey

    2011-03-01

    The ever increasing demand for high-power, high-reliability operation of single emitters at 9xx nm wavelengths requires the development of laser diodes with improved facet regions immune to both catastrophic and wear-out failure modes. In our study, we have evaluated several laser facet definition technologies in application to 90 micron aperture single emitters in asymmetric design (In)GaAs/AlGaAs based material emitting at 915, 925 and 980nm. A common epitaxy and emitter design makes for a straightforward comparison of the facet technologies investigated. Our study corroborates a clear trend of increasing difficulty in obtaining reliable laser operation from 980nm down to 915nm. At 980nm, one can employ dielectric facet passivation with a pre-clean cycle delivering a device lifetime in excess of 3,000 hours at increasing current steps. At 925nm, quantum-well intermixing can be used to define non-absorbing mirrors giving good device reliability, albeit with a large efficiency penalty. Vacuum cleaved emitters have delivered excellent reliability at 915nm, and can be expected to perform just as well at 925 and 980nm. Epitaxial regrowth of laser facets is under development and has yet to demonstrate an appreciable reliability improvement. Only a weak correlation between start-of-life catastrophic optical mirror damage (COMD) levels and reliability was established. The optimized facet design has delivered maximum powers in excess of 19 MW/sq.cm (rollover limited) and product-grade 980nm single emitters with a slope efficiency of >1 W/A and a peak efficiency of >60%. The devices have accumulated over 1,500 hours of CW operation at 11W. A fiber-coupled device emits 10W ex-fiber with 47% efficiency.

  19. Engineering Model of High Pressure Moist Air

    NASA Astrophysics Data System (ADS)

    Hyhlík, Tomáš

    The article deals with the moist air equation of state. There are equations of state discussed in the article, i.e. the model of an ideal mixture of ideal gases, the model of an ideal mixture of real gases and the model based on the virial equation of state. The evaluation of sound speed based on the ideal mixture concept is mentioned. The sound speed calculated by the model of an ideal mixture of ideal gases is compared with the sound speed calculated by using the model based on the concept of an ideal mixture of real gases. The comparison of enthalpy end entropy based on the model of an ideal mixture of ideal gases and the model of an ideal mixture of real gases is performed. It is shown that the model of an ideal mixture of real gases deviates from the model of an ideal mixture of ideal gases only in the case of high pressure. An impossibility of the definition of partial pressure in the mixture of real gases is discussed, where the virial equation of state is used.

  20. High-End Computing Challenges in Aerospace Design and Engineering

    NASA Technical Reports Server (NTRS)

    Bailey, F. Ronald

    2004-01-01

    High-End Computing (HEC) has had significant impact on aerospace design and engineering and is poised to make even more in the future. In this paper we describe four aerospace design and engineering challenges: Digital Flight, Launch Simulation, Rocket Fuel System and Digital Astronaut. The paper discusses modeling capabilities needed for each challenge and presents projections of future near and far-term HEC computing requirements. NASA's HEC Project Columbia is described and programming strategies presented that are necessary to achieve high real performance.

  1. Highly engineered biocatalysts for efficient small molecule pharmaceutical synthesis.

    PubMed

    Lalonde, Jim

    2016-12-01

    Technologies for the engineering of biocatalysts for efficient synthesis of pharmaceutical targets have advanced dramatically over the last few years. Integration of computational methods for structural modeling, combined with high through put methods for expression and screening of biocatalysts and algorithms for mining experimental data, have allowed the creation of highly engineered biocatalysts for the efficient synthesis of pharmaceuticals. Methods for the synthesis of chiral alcohols and amines have been particularly successful, along with the creation of non-natural activities for such desirable reactions as cyclopropanation and esterification. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Highly localized divergence within supergenes in Atlantic cod (Gadus morhua) within the Gulf of Maine.

    PubMed

    Barney, Bryan T; Munkholm, Christiane; Walt, David R; Palumbi, Stephen R

    2017-03-31

    Atlantic cod (Gadus morhua), is known to vary genetically across the North Atlantic, Greenland, and Newfoundland. This genetic variation occurs both spatially and temporally through decades of heavy fishing, and is concentrated in three linkage disequilibrium blocks, previously defined by pedigreed linkage mapping analysis. Variation within these genomic regions is correlated with both seawater temperature and behavioral ecotype. The full extent and nature of these linkage groups is important information for interpreting cod genetic structure as a tool for future fisheries management. We conducted whole genome sequencing for 31 individual cod from three sub-populations in the Gulf of Maine. Across the genome, we found 3,390,654 intermediate to high frequency Single Nucleotide Polymorphisms (SNPs). We show that pairwise linkage analysis among these SNPs is a powerful tool to detect linkage disequilibrium clusters by recovering the three previously detected linkage groups and identifying the 1031 genes contained therein. Across these genes, we found significant population differentiation among spawning groups in the Gulf of Maine and between Georges Bank and Gulf of Maine. Coordinated divergence among these genes and their differentiation at both short and long spatial scales suggests that they are acting as linked supergenes in local adaptation of cod populations. Differentiation between SNPs in linkage disequilibrium blocks is the major signal of genetic differentiation between all groups tested within the Gulf of Maine. Our data provide a map of genes contained in these blocks, allowing an enhanced search for neutral genetic structure for demographic inference and fisheries modeling. Patterns of selection and the history of populations may be possible to identify in cod using this description of linkage disequilibrium blocks and future data sets to robustly separate neutral and selected genetic markers.

  3. SSME/side loads analysis for flight configuration, revision A. [structural analysis of space shuttle main engine under side load excitation

    NASA Technical Reports Server (NTRS)

    Holland, W.

    1974-01-01

    This document describes the dynamic loads analysis accomplished for the Space Shuttle Main Engine (SSME) considering the side load excitation associated with transient flow separation on the engine bell during ground ignition. The results contained herein pertain only to the flight configuration. A Monte Carlo procedure was employed to select the input variables describing the side load excitation and the loads were statistically combined. This revision includes an active thrust vector control system representation and updated orbiter thrust structure stiffness characteristics. No future revisions are planned but may be necessary as system definition and input parameters change.

  4. The Cornell Main Linac Cryomodule: A Full Scale, High Q Accelerator Module for cw Application

    NASA Astrophysics Data System (ADS)

    Eichhorn, R.; Bullock, B.; Elmore, B.; Clasby, B.; Furuta, F.; He, Y.; Hoffstaetter, G.; Liepe, M.; O'Connell, T.; Conway, J.; Quigley, P.; Sabol, D.; Sears, J.; Smith, E.; Veshcherevich, V.

    Cornell University is in the process of building a 10 m long superconducting accelerator module as a prototype of the main linac of a proposed ERL facility. This module houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/BPM section. In pushing the limits, a high quality factor of the cavities (2•1010) and high beam currents (100 mA accelerated plus 100 mA decelerated) were targeted. We will review the design shortly and present the results of the components tested before the assembly. This includes data of the quality-factors of all 6 cavities that we produced and treated in-house, the HOM absorber performance measured with beam on a test set-up as well as testing of the couplers and the tuners.

  5. The High Stability Engine Control (HISTEC) Program: Flight Demonstration Phase

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Southwick, Robert D.; Gallops, George W.; Orme, John S.

    1998-01-01

    Future aircraft turbine engines, both commercial and military, must be able to accommodate expected increased levels of steady-state and dynamic engine-face distortion. The current approach of incorporating sufficient design stall margin to tolerate these increased levels of distortion would significantly reduce performance. The objective of the High Stability Engine Control (HISTEC) program is to design, develop, and flight-demonstrate an advanced, integrated engine control system that uses measurement-based estimates of distortion to enhance engine stability. The resulting distortion tolerant control reduces the required design stall margin, with a corresponding increase in performance and decrease in fuel burn. The HISTEC concept has been developed and was successfully flight demonstrated on the F-15 ACTIVE aircraft during the summer of 1997. The flight demonstration was planned and carried out in two phases, the first to show distortion estimation, and the second to show distortion accommodation. Post-flight analysis shows that the HISTEC technologies are able to successfully estimate and accommodate distortion, transiently setting the stall margin requirement on-line and in real-time. This allows the design stall margin requirement to be reduced, which in turn can be traded for significantly increased performance and/or decreased weight. Flight demonstration of the HISTEC technologies has significantly reduced the risk of transitioning the technology to tactical and commercial engines.

  6. Profiling the main cell wall polysaccharides of grapevine leaves using high-throughput and fractionation methods.

    PubMed

    Moore, John P; Nguema-Ona, Eric; Fangel, Jonatan U; Willats, William G T; Hugo, Annatjie; Vivier, Melané A

    2014-01-01

    Vitis species include Vitis vinifera, the domesticated grapevine, used for wine and grape agricultural production and considered the world's most important fruit crop. A cell wall preparation, isolated from fully expanded photosynthetically active leaves, was fractionated via chemical and enzymatic reagents; and the various extracts obtained were assayed using high-throughput cell wall profiling tools according to a previously optimized and validated workflow. The bulk of the homogalacturonan-rich pectin present was efficiently extracted using CDTA treatment, whereas over half of the grapevine leaf cell wall consisted of vascular veins, comprised of xylans and cellulose. The main hemicellulose component was found to be xyloglucan and an enzymatic oligosaccharide fingerprinting approach was used to analyze the grapevine leaf xyloglucan fraction. When Paenibacillus sp. xyloglucanase was applied the main subunits released were XXFG and XLFG; whereas the less-specific Trichoderma reesei EGII was also able to release the XXXG motif as well as other oligomers likely of mannan and xylan origin. This latter enzyme would thus be useful to screen for xyloglucan, xylan and mannan-linked cell wall alterations in laboratory and field grapevine populations. This methodology is well-suited for high-throughput cell wall profiling of grapevine mutant and transgenic plants for investigating the range of biological processes, specifically plant disease studies and plant-pathogen interactions, where the cell wall plays a crucial role. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. The Main Sequences of Star-forming Galaxies and Active Galactic Nuclei at High Redshift

    NASA Astrophysics Data System (ADS)

    Mancuso, C.; Lapi, A.; Shi, J.; Cai, Z.-Y.; Gonzalez-Nuevo, J.; Béthermin, M.; Danese, L.

    2016-12-01

    We provide a novel, unifying physical interpretation on the origin, average shape, scatter, and cosmic evolution for the main sequences of star-forming galaxies and active galactic nuclei (AGNs) at high redshift z≳ 1. We achieve this goal in a model-independent way by exploiting: (i) the redshift-dependent star formation rate functions based on the latest UV/far-IR data from HST/Herschel, and related statistics of strong gravitationally lensed sources; (ii) deterministic evolutionary tracks for the history of star formation and black hole accretion, gauged on a wealth of multiwavelength observations including the observed Eddington ratio distribution. We further validate these ingredients by showing their consistency with the observed galaxy stellar mass functions and AGN bolometric luminosity functions at different redshifts via the continuity equation approach. Our analysis of the main sequence for high-redshift galaxies and AGNs highlights that the present data are consistently interpreted in terms of an in situ coevolution scenario for star formation and black hole accretion, envisaging these as local, time-coordinated processes.

  8. Protein engineering by highly parallel screening of computationally designed variants

    PubMed Central

    Sun, Mark G. F.; Seo, Moon-Hyeong; Nim, Satra; Corbi-Verge, Carles; Kim, Philip M.

    2016-01-01

    Current combinatorial selection strategies for protein engineering have been successful at generating binders against a range of targets; however, the combinatorial nature of the libraries and their vast undersampling of sequence space inherently limit these methods due to the difficulty in finely controlling protein properties of the engineered region. Meanwhile, great advances in computational protein design that can address these issues have largely been underutilized. We describe an integrated approach that computationally designs thousands of individual protein binders for high-throughput synthesis and selection to engineer high-affinity binders. We show that a computationally designed library enriches for tight-binding variants by many orders of magnitude as compared to conventional randomization strategies. We thus demonstrate the feasibility of our approach in a proof-of-concept study and successfully obtain low-nanomolar binders using in vitro and in vivo selection systems. PMID:27453948

  9. High-Temperature Magnetic Bearings for Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Magnetic bearings are the subject of a new NASA Lewis Research Center and U.S. Army thrust with significant industry participation, and coordination with other Government agencies. The NASA/Army emphasis is on high-temperature applications for future gas turbine engines. Magnetic bearings could increase the reliability and reduce the weight of these engines by eliminating the lubrication system. They could also increase the DN (diameter of the bearing times rpm) limit on engine speed and allow active vibration cancellation systems to be used--resulting in a more efficient, "more electric" engine. Finally, the Integrated High-Performance Turbine Engine Technology (IHPTET) Program, a joint Department of Defense/industry program, identified a need for a hightemperature (as high as 1200 F) magnetic bearing that could be demonstrated in a phase III engine. This magnetic bearing is similar to an electric motor. It has a laminated rotor and stator made of cobalt steel. Wound around the stator are a series of electrical wire coils that form a series of electric magnets around the circumference. The magnets exert a force on the rotor. A probe senses the position of the rotor, and a feedback controller keeps it in the center of the cavity. The engine rotor, bearings, and case form a flexible structure that contains a large number of modes. The bearing feedback controller, which could cause some of these modes to become unstable, could be adapted to varying flight conditions to minimize seal clearances and monitor the health of the system. Cobalt steel has a curie point greater than 1700 F, and copper wire has a melting point beyond that. Therefore, practical limitations associated with the maximum magnetic field strength in the cobalt steel and the stress in the rotating components limit the temperature to about 1200 F. The objective of this effort is to determine the limits in temperature and speed of a magnetic bearing operating in an engine. Our approach is to use our in

  10. Valley-engineered ultra-thin silicon for high-performance junctionless transistors

    PubMed Central

    Kim, Seung-Yoon; Choi, Sung-Yool; Hwang, Wan Sik; Cho, Byung Jin

    2016-01-01

    Extremely thin silicon show good mechanical flexibility because of their 2-D like structure and enhanced performance by the quantum confinement effect. In this paper, we demonstrate a junctionless FET which reveals a room temperature quantum confinement effect (RTQCE) achieved by a valley-engineering of the silicon. The strain-induced band splitting and a quantum confinement effect induced from ultra-thin-body silicon are the two main mechanisms for valley engineering. These were obtained from the extremely well-controlled silicon surface roughness and high tensile strain in silicon, thereupon demonstrating a device mobility increase of ~500% in a 2.5 nm thick silicon channel device. PMID:27389874

  11. A Study of Work Family Integration Issues. Research of 1987 Sophomores from Eight Maine High Schools Conducted by the Maine Occupational Information Coordinating Committee and the Rural Career Development Group (Maine School Administrative District #44).

    ERIC Educational Resources Information Center

    Hoyt, Kenneth B.; And Others

    This report describes an inquiry into the work attitudes and career decision making skills of 754 sophomores in seven rural and one urban high school in Maine. The study is the first part of a planned 7-year longitudinal study that will interview these students again when they are seniors and then again 5 years later. The eight papers in the…

  12. Optical engineering

    SciTech Connect

    Saito, T T

    1998-01-01

    The Optical Engineering thrust area at Lawrence Livermore National Laboratory (LLNL) was created in the summer of 1996 with the following main objectives: (1) to foster and stimulate leading edge optical engineering research and efforts key to carrying out LLNL's mission and enabling major new programs; (2) to bring together LLNL's broad spectrum of high level optical engineering expertise to support its programs. Optical engineering has become a pervasive and key discipline, with applications across an extremely wide range of technologies, spanning the initial conception through the engineering refinements to enhance revolutionary application. It overlaps other technologies and LLNL engineering thrust areas.

  13. High-performance diesel engines power high-speed hydrofoil catamaran

    SciTech Connect

    Not Available

    1994-10-01

    The speed of any sea-water craft is dependent on the design of its engine. Mitsubishi Heavy industries has developed a high-speed, fully submerged, super shuttle 400 hydrofoil catamaran ferry, which uses high-performance diesel engines to reach speeds up to 45 knots. The twin-hull design with V section forms permits the use of wide hydrofoils, allowing substantial lifting power. Each of the 16-cylinder engines has a maximum continuous output of 2100 kW at a maximum speed of 2000 r/min. Each catamaran section holds two engines driving a Mitsubishi MWJ-5000A waterjet through a combining reduction gear. 3 figs.

  14. Analytical screening of low emissions, high performance duct burners for supersonic cruise aircraft engines

    NASA Technical Reports Server (NTRS)

    Lohmann, R. A.; Riecke, G. T.

    1977-01-01

    An analytical screening study was conducted to identify duct burner concepts capable of providing low emissions and high performance in advanced supersonic engines. Duct burner configurations ranging from current augmenter technology to advanced concepts such as premix-prevaporized burners were defined. Aerothermal and mechanical design studies provided the basis for screening these configurations using the criteria of emissions, performance, engine compatibility, cost, weight and relative risk. Technology levels derived from recently defined experimental low emissions main burners are required to achieve both low emissions and high performance goals. A configuration based on the Vorbix (Vortex burning and mixing) combustor concept was analytically determined to meet the performance goals and is consistent with the fan duct envelope of a variable cycle engine. The duct burner configuration has a moderate risk level compatible with the schedule of anticipated experimental programs.

  15. Promoting Engineering Education among High School and Middle School Students

    ERIC Educational Resources Information Center

    Goonatilake, Rohitha; Bachnak, Rafic A.

    2012-01-01

    Recent decline of students pursuing engineering degree programs is a great concern for many higher education authorities including Federal and State governments. Existing programs in high schools have not yet produced the desired results. Consequently, a number of initiatives to remedy this situation have been proposed and implemented. One such…

  16. Implementing Concepts of Pharmaceutical Engineering into High School Science Classrooms

    ERIC Educational Resources Information Center

    Kimmel, Howard; Hirsch, Linda S.; Simon, Laurent; Burr-Alexander, Levelle; Dave, Rajesh

    2009-01-01

    The Research Experience for Teachers was designed to help high school science teachers develop skills and knowledge in research, science and engineering with a focus on the area of pharmaceutical particulate and composite systems. The experience included time for the development of instructional modules for classroom teaching. Results of the…

  17. HI-TIE: The University, the High School, and Engineering

    ERIC Educational Resources Information Center

    Ward, Robert C.; Maxwell, Lee M.

    1975-01-01

    Describes four years experience at Colorado State University with courses introducing high school students to engineering, including a Fortran IV computer programming course in which tapings of actual campus classroom sessions, supplemented with homework assignments, class roles, quizzes, and examinations were used. Benefits of the transitional…

  18. High School Student Information Access and Engineering Design Performance

    ERIC Educational Resources Information Center

    Mentzer, Nathan

    2014-01-01

    Developing solutions to engineering design problems requires access to information. Research has shown that appropriately accessing and using information in the design process improves solution quality. This quasi-experimental study provides two groups of high school students with a design problem in a three hour design experience. One group has…

  19. Implementing Concepts of Pharmaceutical Engineering into High School Science Classrooms

    ERIC Educational Resources Information Center

    Kimmel, Howard; Hirsch, Linda S.; Simon, Laurent; Burr-Alexander, Levelle; Dave, Rajesh

    2009-01-01

    The Research Experience for Teachers was designed to help high school science teachers develop skills and knowledge in research, science and engineering with a focus on the area of pharmaceutical particulate and composite systems. The experience included time for the development of instructional modules for classroom teaching. Results of the…

  20. Promoting Engineering Education among High School and Middle School Students

    ERIC Educational Resources Information Center

    Goonatilake, Rohitha; Bachnak, Rafic A.

    2012-01-01

    Recent decline of students pursuing engineering degree programs is a great concern for many higher education authorities including Federal and State governments. Existing programs in high schools have not yet produced the desired results. Consequently, a number of initiatives to remedy this situation have been proposed and implemented. One such…

  1. High School Student Information Access and Engineering Design Performance

    ERIC Educational Resources Information Center

    Mentzer, Nathan

    2014-01-01

    Developing solutions to engineering design problems requires access to information. Research has shown that appropriately accessing and using information in the design process improves solution quality. This quasi-experimental study provides two groups of high school students with a design problem in a three hour design experience. One group has…

  2. Synchronizing Photography For High-Speed-Engine Research

    NASA Technical Reports Server (NTRS)

    Chun, K. S.

    1989-01-01

    Light flashes when shaft reaches predetermined angle. Synchronization system facilitates visualization of flow in high-speed internal-combustion engines. Designed for cinematography and holographic interferometry, system synchronizes camera and light source with predetermined rotational angle of engine shaft. 10-bit resolution of absolute optical shaft encoder adapted, and 2 to tenth power combinations of 10-bit binary data computed to corresponding angle values. Pre-computed angle values programmed into EPROM's (erasable programmable read-only memories) to use as angle lookup table. Resolves shaft angle to within 0.35 degree at rotational speeds up to 73,240 revolutions per minute.

  3. Synchronizing Photography For High-Speed-Engine Research

    NASA Technical Reports Server (NTRS)

    Chun, K. S.

    1989-01-01

    Light flashes when shaft reaches predetermined angle. Synchronization system facilitates visualization of flow in high-speed internal-combustion engines. Designed for cinematography and holographic interferometry, system synchronizes camera and light source with predetermined rotational angle of engine shaft. 10-bit resolution of absolute optical shaft encoder adapted, and 2 to tenth power combinations of 10-bit binary data computed to corresponding angle values. Pre-computed angle values programmed into EPROM's (erasable programmable read-only memories) to use as angle lookup table. Resolves shaft angle to within 0.35 degree at rotational speeds up to 73,240 revolutions per minute.

  4. High-resolution modeling assessment of tidal stream resource in Western Passage of Maine, USA

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoqing; Wang, Taiping; Feng, Xi; Xue, Huijie; Kilcher, Levi

    2017-04-01

    Although significant efforts have been taken to assess the maximum potential of tidal stream energy at system-wide scale, accurate assessment of tidal stream energy resource at project design scale requires detailed hydrodynamic simulations using high-resolution three-dimensional (3-D) numerical models. Extended model validation against high quality measured data is essential to minimize the uncertainties of the resource assessment. Western Passage in the State of Maine in U.S. has been identified as one of the top ranking sites for tidal stream energy development in U.S. coastal waters, based on a number of criteria including tidal power density, market value and transmission distance. This study presents an on-going modeling effort for simulating the tidal hydrodynamics in Western Passage using the 3-D unstructured-grid Finite Volume Community Ocean Model (FVCOM). The model domain covers a large region including the entire the Bay of Fundy with grid resolution varies from 20 m in the Western Passage to approximately 1000 m along the open boundary near the mouth of Bay of Fundy. Preliminary model validation was conducted using existing NOAA measurements within the model domain. Spatial distributions of tidal power density were calculated and extractable tidal energy was estimated using a tidal turbine module embedded in FVCOM under different tidal farm scenarios. Additional field measurements to characterize resource and support model validation were discussed. This study provides an example of high resolution resource assessment based on the guidance recommended by the International Electrotechnical Commission Technical Specification.

  5. Main drive optimization of a high-foot pulse shape in inertial confinement fusion implosions

    NASA Astrophysics Data System (ADS)

    Wang, L. F.; Ye, W. H.; Wu, J. F.; Liu, Jie; Zhang, W. Y.; He, X. T.

    2016-12-01

    While progress towards hot-spot ignition has been made achieving an alpha-heating dominated state in high-foot implosion experiments [Hurricane et al., Nat. Phys. 12, 800 (2016)] on the National Ignition Facility, improvements are needed to increase the fuel compression for the enhancement of the neutron yield. A strategy is proposed to improve the fuel compression through the recompression of a shock/compression wave generated by the end of the main drive portion of a high-foot pulse shape. Two methods for the peak pulse recompression, namely, the decompression-and-recompression (DR) and simple recompression schemes, are investigated and compared. Radiation hydrodynamic simulations confirm that the peak pulse recompression can clearly improve fuel compression without significantly compromising the implosion stability. In particular, when the convergent DR shock is tuned to encounter the divergent shock from the capsule center at a suitable position, not only the neutron yield but also the stability of stagnating hot-spot can be noticeably improved, compared to the conventional high-foot implosions [Hurricane et al., Phys. Plasmas 21, 056314 (2014)].

  6. Probabilistic Structural Analysis Methods for select space propulsion system components (PSAM). Volume 2: Literature surveys of critical Space Shuttle main engine components

    NASA Technical Reports Server (NTRS)

    Rajagopal, K. R.

    1992-01-01

    The technical effort and computer code development is summarized. Several formulations for Probabilistic Finite Element Analysis (PFEA) are described with emphasis on the selected formulation. The strategies being implemented in the first-version computer code to perform linear, elastic PFEA is described. The results of a series of select Space Shuttle Main Engine (SSME) component surveys are presented. These results identify the critical components and provide the information necessary for probabilistic structural analysis. Volume 2 is a summary of critical SSME components.

  7. Current Status of High Voltage Engineering in Indonesia

    NASA Astrophysics Data System (ADS)

    Hidayat, Syarif; Hidayat, Suwarno; Zoro, Reynaldo

    This paper reports current status of research activities in the field of high voltage engineering and its application in Indonesia. In general, the activities were driven by the application of high voltage (HV) and extra high voltage (EHV) transmission systems in the country. The operation and maintenance of HV and EHV equipments are greatly affected by the tropical climate of the country. This attracts researchers to investigate the effects of tropical climate on HV and EHV equipments. Other researches concentrated on the investigation of physics of tropical lightning and lightning protection. In this paper, applications and problems of high voltage engineering, research activities in universities, as well as in research institutes and utilities are briefly introduced.

  8. Highly-nonlinear quantum-engineered polaritonic metasurfaces

    NASA Astrophysics Data System (ADS)

    Lee, Jongwon; Nookala, Nishant; Gomez-Diaz, Juan Sebastian; Tymchenko, Mykhailo; Demmerle, Frederic; Boehm, Gerhard; Amann, Markus-Christian; Alù, Andrea; Belkin, Mikhail A.

    2015-08-01

    Intersubband transitions in n-doped semiconductor heterostructures allow one to quantum-engineer one of the largest known nonlinear response in condensed matter systems but only for the electric field polarized normal to semiconductor layer. By coupling of a quantum-engineered multi-quantum-well semiconductor layer with electromagnetically-engineered plasmonic elements we may produce ultrathin metasurfaces with giant nonlinear response. Here we experimentally demonstrate metasurfaces designed for second harmonic generation at λ≍9.9 μm with a record-high nonlinear response for condensed-matter systems in infrared/visible spectral range, up to 1.17×106 pm/V. The practical impact of the nonlinear metasurfaces proposed here may be extended to a variety of fields, including THz generation and detection, phase conjugation, and other nonlinear optical processes.

  9. Engineering biosynthesis of high-value compounds in photosynthetic organisms.

    PubMed

    O'Neill, Ellis C; Kelly, Steven

    2016-10-04

    The photosynthetic, autotrophic lifestyle of plants and algae position them as ideal platform organisms for sustainable production of biomolecules. However, their use in industrial biotechnology is limited in comparison to heterotrophic organisms, such as bacteria and yeast. This usage gap is in part due to the challenges in generating genetically modified plants and algae and in part due to the difficulty in the development of synthetic biology tools for manipulating gene expression in these systems. Plant and algal metabolism, pre-installed with multiple biosynthetic modules for precursor compounds, bypasses the requirement to install these pathways in conventional production organisms, and creates new opportunities for the industrial production of complex molecules. This review provides a broad overview of the successes, challenges and future prospects for genetic engineering in plants and algae for enhanced or de novo production of biomolecules. The toolbox of technologies and strategies that have been used to engineer metabolism are discussed, and the potential use of engineered plants for industrial manufacturing of large quantities of high-value compounds is explored. This review also discusses the routes that have been taken to modify the profiles of primary metabolites for increasing the nutritional quality of foods as well as the production of specialized metabolites, cosmetics, pharmaceuticals and industrial chemicals. As the universe of high-value biosynthetic pathways continues to expand, and the tools to engineer these pathways continue to develop, it is likely plants and algae will become increasingly valuable for the biomanufacturing of high-value compounds.

  10. Effects of Professional Development on Infusing Engineering Design into High School Science, Technology, Engineering, and Math (STEM) Curricula

    ERIC Educational Resources Information Center

    Avery, Zanj Kano

    2010-01-01

    The purpose of this study was to examine the effects of professional development (PD) on the infusion of engineering design into high school curricula. Four inservice teachers with backgrounds in physics, chemistry, industrial education, math, and electrical engineering participated in the 2006 National Center of Engineering and Technology…

  11. Effects of Professional Development on Infusing Engineering Design into High School Science, Technology, Engineering, and Math (STEM) Curricula

    ERIC Educational Resources Information Center

    Avery, Zanj Kano

    2010-01-01

    The purpose of this study was to examine the effects of professional development (PD) on the infusion of engineering design into high school curricula. Four inservice teachers with backgrounds in physics, chemistry, industrial education, math, and electrical engineering participated in the 2006 National Center of Engineering and Technology…

  12. Impact of Maine's statewide nutrition policy on high school food environments.

    PubMed

    Whatley Blum, Janet E; Beaudoin, Christina M; O'Brien, Liam M; Polacsek, Michele; Harris, David E; O'Rourke, Karen A

    2011-01-01

    We assessed the effect on the food environments of public high schools of Maine's statewide nutrition policy (Chapter 51), which banned "foods of minimal nutritional value" (FMNV) in public high schools that participated in federally funded meal programs. We documented allowable exceptions to the policy and describe the school food environments. We mailed surveys to 89 high school food-service directors to assess availability pre-Chapter 51 and post-Chapter 51 of soda, other sugar-sweetened beverages, and junk food. Frequency data were tabulated pre-Chapter 51 and post-Chapter 51, and Fisher exact test was used to assess significance in changes. We conducted food and beverage inventories at 11 high schools. The survey return rate was 61% (N = 54). Availability of soda in student vending significantly decreased pre-Chapter 51 versus post-Chapter 51 (P = .04). No significant changes were found for other sugar-sweetened beverages and junk food. Exceptions to Chapter 51 were permitted to staff (67%), to the public (86%), and in career and technical education programs (31%). Inventories in a subset of schools found no availability of soda for students, whereas other sugar-sweetened beverages and junk food were widely available in à la carte, vending machines, and school stores. Candy, considered a FMNV, was freely available. Soda advertisement on school grounds was common. Student vending choices improved after the implementation of Chapter 51; however, use of FMNV as the policy standard may be limiting, as availability of other sugar-sweetened beverages and junk food was pervasive. School environments were not necessarily supportive of the policy, as advertisement of soda was common and some FMNV were available. Furthermore, local exceptions to Chapter 51 likely reduced the overall effect of the policy.

  13. Proficiency-Based High School Diploma Systems in Maine: Implications for College and Career Access

    ERIC Educational Resources Information Center

    Stump, Erika; Fairman, Janet; Doykos, Bernadette; Fink, Paul

    2017-01-01

    In the 127th Legislative Session, "An Act to Implement Certain Recommendations of the Maine Proficiency Education Council" (S.P. 660 - L.D. 1627) was passed into law as Chapter 489 amending the chaptered law "An Act to Prepare Maine People for the Future Economy" (S.P.439 - L.D.1422) passed in 2012 requiring Maine school…

  14. Space charge measurements with a high intensity bunch at the Fermilab Main Injector

    SciTech Connect

    Seiya, K.; Chase, B.; Dey, J.; Joireman, P.; Kourbanis, I.; Yagodnitsyna, A.; /Novosibirsk State U.

    2011-03-01

    For Project X, the Fermilab Main Injector will be required to operate with 3 times higher bunch intensity. The plan to study the space charge effects at the injection energy with intense bunches will be discussed. A multi-MW proton facility has been established as a critical need for the U.S. HEP program by HEPAP and P5. Utilization of the Main Injector (MI) as a high intensity proton source capable of delivering in excess of 2 MW beam power will require a factor of three increase in bunch intensity compared to current operations. Instabilities associated with beam loading, space charge, and electron cloud effects are common issues for high intensity proton machines. The MI intensities for current operations and Project X are listed in Table 1. The MI provides proton beams for Fermilab's Tevatron Proton-Antiproton Collider and MINOS neutrino experiments. The proposed 2MW proton facility, Project X, utilizes both the Recycler (RR) and the MI. The RR will be reconfigured as a proton accumulator and injector to realize the factor 3 bunch intensity increase in the MI. Since the energy in the RR and the MI at injection will be 6-8 GeV, which is relatively low, space charge effects will be significant and need to be studied. Studies based on the formation of high intensity bunches in the MI will guide the design and fabrication of the RF cavities and space-charge mitigation devices required for 2 MW operation of the MI. It is possible to create the higher bunch intensities required in the MI using a coalescing technique that has been successfully developed at Fermilab. This paper will discuss a 5 bunch coalescing scheme at 8 GeV which will produce 2.5 x 10{sup 11} protons in one bunch. Bunch stretching will be added to the coalescing process. The required RF parameters were optimized with longitudinal simulations. The beam studies, that have a goal of 85% coalescing efficiency, were started in June 2010.

  15. Evaluating the main and side effects of high salinity on aerobic granular sludge.

    PubMed

    Pronk, M; Bassin, J P; de Kreuk, M K; Kleerebezem, R; van Loosdrecht, M C M

    2014-02-01

    Salinity can adversely affect the performance of most biological processes involved in wastewater treatment. The effect of salt on the main conversion processes in an aerobic granular sludge (AGS) process accomplishing simultaneous organic matter, nitrogen, and phosphate removal was evaluated in this work. Hereto, an AGS sequencing batch reactor was subjected to different salt concentrations (0.2 to 20 g Cl(-) l(-1)). Granular structure was stable throughout the whole experimental period, although granule size decreased and a significant effluent turbidity was observed at the highest salinity tested. A weaker gel structure at higher salt concentrations was hypothesised to be the cause of such turbidity. Ammonium oxidation was not affected at any of the salt concentrations applied. However, nitrite oxidation was severely affected, especially at 20 g Cl(-) l(-1), in which a complete inhibition was observed. Consequently, high nitrite accumulation occurred. Phosphate removal was also found to be inhibited at the highest salt concentration tested. Complementary experiments have shown that a cascade inhibition effect took place: first, the deterioration of nitrite oxidation resulted in high nitrite concentrations and this in turn resulted in a detrimental effect to polyphosphate-accumulating organisms. By preventing the occurrence of the nitrification process and therefore avoiding the nitrite accumulation, the effect of salt concentrations on the bio-P removal process was shown to be negligible up to 13 g Cl(-) l(-1). Salt concentrations equal to 20 g Cl(-) l(-1) or higher in absence of nitrite also significantly reduced phosphate removal efficiency in the system.

  16. 21. VIEW TO NORTHWEST, ENGINE/PUMP HOUSE EXTENSION, HIGH PRESSURE PISTON ...

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

    21. VIEW TO NORTHWEST, ENGINE/PUMP HOUSE EXTENSION, HIGH PRESSURE PISTON OF STEAM ENGINE NO. 4; CONTROL PANEL MOUNTED ON THE ENGINE; FLOOR VALVES CONTROL THE STEAM. - Deer Island Pumping Station, Boston, Suffolk County, MA

  17. Quantitative aspects of microchip isotachophoresis for high precision determination of main components in pharmaceuticals.

    PubMed

    Hradski, Jasna; Chorváthová, Mária Drusková; Bodor, Róbert; Sabo, Martin; Matejčík, Štefan; Masár, Marián

    2016-12-01

    Although microchip electrophoresis (MCE) is intended to provide reliable quantitative data, so far there is only limited attention paid to these important aspects. This study gives a general overview of key aspects to be followed to reach high-precise determination using isotachophoresis (ITP) on the microchip with conductivity detection. From the application point of view, the procedure for the determination of acetate, a main component in the pharmaceutical preparation buserelin acetate, was developed. Our results document that run-to-run fluctuations in the sample injection volume limit the reproducibility of quantitation based on the external calibration. The use of a suitable internal standard (succinate in this study) improved the repeatability of the precision of acetate determination from six to eight times. The robustness of the procedure was studied in terms of impact of fluctuations in various experimental parameters (driving current, concentration of the leading ions, pH of the leading electrolyte and buffer impurities) on the precision of the ITP determination. The use of computer simulation programs provided means to assess the ITP experiments using well-defined theoretical models. A long-term validity of the calibration curves on two microchips and two MCE equipments was verified. This favors ITP over other microchip electrophoresis techniques, when chip-to-chip or equipment-to-equipment transfer of the analytical method is required. The recovery values in the range of 98-101 % indicate very accurate determination of acetate in buserelin acetate, which is used in the treatment of hormone-dependent tumors. This study showed that microchip ITP is suitable for reliable determination of main components in pharmaceutical preparations.

  18. Engine having a high pressure hydraulic system and low pressure lubricating system

    DOEpatents

    Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

    2000-01-01

    An engine includes a high pressure hydraulic system having a high pressure pump and at least one hydraulically-actuated device attached to an engine housing. A low pressure engine lubricating system is attached to the engine housing and includes a circulation conduit fluidly connected to an outlet from the high pressure pump.

  19. High-Speed Visualisation of Combustion in Modern Gasoline Engines

    NASA Astrophysics Data System (ADS)

    Sauter, W.; Nauwerck, A.; Han, K.-M.; Pfeil, J.; Velji, A.; Spicher, U.

    2006-07-01

    Today research and development in the field of gasoline engines have to face a double challenge: on the one hand, fuel consumption has to be reduced, while on the other hand, ever more stringent emission standards have to be fulfilled. The development of engines with its complexity of in-cylinder processes requires modern development tools to exploit the full potential in order to reduce fuel consumption. Especially optical, non-intrusive measurement techniques will help to get a better understanding of the processes. With the presented high-speed visualisation system the electromagnetic radiation from combustion in the UV range is collected by an endoscope and transmitted to a visualisation system by 10, 000 optical fibres. The signal is projected to 1, 920 photomultipliers, which convert the optical into electric signals with a maximum temporal resolution of 200 kHz. This paper shows the systematic application of flame diagnostics in modern combustion systems. For this purpose, a single-cylinder SI engine has been modified for a spray guided combustion strategy as well as for HCCI. The characteristics of flame propagation in both combustion modes were recorded and correlated with thermodynamic analyses. In case of the spray guided GDI engine, high pressure fuel injection was applied and evaluated.

  20. A High Throughput Mechanical Screening Device for Cartilage Tissue Engineering

    PubMed Central

    Mohanraj, Bhavana; Hou, Chieh; Meloni, Greg R.; Cosgrove, Brian D.; Dodge, George R.; Mauck, Robert L.

    2014-01-01

    Articular cartilage enables efficient and near-frictionless load transmission, but suffers from poor inherent healing capacity. As such, cartilage tissue engineering strategies have focused on mimicking both compositional and mechanical properties of native tissue in order to provide effective repair materials for the treatment of damaged or degenerated joint surfaces. However, given the large number design parameters available (e.g. cell sources, scaffold designs, and growth factors), it is difficult to conduct combinatorial experiments of engineered cartilage. This is particularly exacerbated when mechanical properties are a primary outcome given the long time required for testing of individual samples. High throughput screening is utilized widely in the pharmaceutical industry to rapidly and cost-effectively assess the effects of thousands of compounds for therapeutic discovery. Here we adapted this approach to develop a high throughput mechanical screening (HTMS) system capable of measuring the mechanical properties of up to 48 materials simultaneously. The HTMS device was validated by testing various biomaterials and engineered cartilage constructs and by comparing the HTMS results to those derived from conventional single sample compression tests. Further evaluation showed that the HTMS system was capable of distinguishing and identifying ‘hits’, or factors that influence the degree of tissue maturation. Future iterations of this device will focus on reducing data variability, increasing force sensitivity and range, as well as scaling-up to even larger (96-well) formats. This HTMS device provides a novel tool for cartilage tissue engineering, freeing experimental design from the limitations of mechanical testing throughput. PMID:24275442