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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7

Future aerospace ground test facility requirements for the Arnold Engineering Development Center

Arnold Engineering Development Center (AEDC) was conceived at the close of World War II, when major new developments in flight technology were presaged by new aerodynamic and propulsion concepts. During the past 40 years, AEDC has played a significant part in the development of many aerospace systems. The original plans were extended through the years by some additional facilities, particularly in the area of propulsion testing. AEDC now has undertaken development of a master plan in an attempt to project requirements and to plan for ground test and computational facilities over the coming 20 to 30 years. This report was prepared in response to an AEDC request that the National Research Council (NRC) assemble a committee to prepare guidance for planning and modernizing AEDC facilities for the development and testing of future classes of aerospace systems as envisaged by the U.S. Air Force.

Kirchner, Mark E.↗

Propulsion/ASME Rocket-Based Combined Cycle Activities in the Advanced Space Transportation Program Office

NASA's Office Of Aeronautics and Space Transportation Technology (OASTT) has establish three major coals. "The Three Pillars for Success". The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center in Huntsville,Ala. focuses on future space transportation technologies under the "Access to Space" pillar. The Advanced Reusable Technologies (ART) Project, part of ASTP, focuses on the reusable technologies beyond those being pursued by X-33. The main activity over the past two and a half years has been on advancing the rocket-based combined cycle (RBCC) technologies. In June of last year, activities for reusable launch vehicle (RLV) airframe and propulsion technologies were initiated. These activities focus primarily on those technologies that support the year 2000 decision to determine the path this country will take for Space Shuttle and RLV. In February of this year, additional technology efforts in the reusable technologies were awarded. The RBCC effort that was completed early this year was the initial step leading to flight demonstrations of the technology for space launch vehicle propulsion. Aerojet, Boeing-Rocketdyne and Pratt & Whitney were selected for a two-year period to design, build and ground test their RBCC engine concepts. In addition, ASTROX, Pennsylvania State University (PSU) and University of Alabama in Huntsville also conducted supporting activities. The activity included ground testing of components (e.g., injectors, thrusters, ejectors and inlets) and integrated flowpaths. An area that has caused a large amount of difficulty in the testing efforts is the means of initiating the rocket combustion process. All three of the prime contractors above were using silane (SiH4) for ignition of the thrusters. This follows from the successful use of silane in the NASP program for scramjet ignition. However, difficulties were immediately encountered when silane (an 80/20 mixture of hydrogen/silane) was used for rocket ignition.

Hueter, Uwe↗

Status of the Advanced Reusable Technologies Project

The Advanced Reusable Technologies (ART) Project, part of the Advanced Space Transportation Program Office at the NASA's Marshall Space Flight Center in Huntsville, Ala., focuses on future reusable technologies beyond those being pursued by X-33. The prime objective of the project is to dramatically reduce the cost of access to space. In April 1996, an NRA was issued soliciting proposals for tasks focusing on rocket-based combined cycle propulsion system (RBCC). In August of 1996, five contractors were selected for a two year period to design and ground test their RBCC engine concepts. The work on these contracts should be completed by the end of this year. In March of this year, another NRA was issued to solicit inputs for reusable vehicle and propulsion technologies applicable to earth-to-orbit and in-space transportation. The current RBCC effort is the first of three phases leading to a large scale flight demonstrations of the technology for space launch vehicle propulsion. This first phase will provide initial verification of proposed concepts through ground demonstration of combined rocket/air breathing propulsion technologies. Using the most promising concepts identified in the first phase, the second phase will design, manufacture and ground test flight-type engine(s) to demonstrate actual design weights and performance. In the third phase, the first flight of a sub-scale integrated X-vehicle is planned for 2002. This paper describes the current status, plans and progress of the ART Project.

Hueter, Ume↗

Engine induced structural-borne noise in a general aviation aircraft

This paper describes a study of engine induced structural-borne noise in a single engine light aircraft. Cabin noise and fuselage vibration levels were recorded during ground tests for engine-attached, engine-detached, interior-installed, and interior-removed configurations. By comparisons of the data, engine induced structure-borne noise is shown to be a primary source of cabin noise. Corresponding fuselage vibration levels were quite high with energy concentrated mainly in the lower frequencies. A measure of the noise control effectiveness of the interior trim was also obtained.

Unruh, J. F.↗

Demonstration of a flight capable system for plume spectroscopy

A small, rugged, high-speed/resolution Fabry-Perot interferometer (FPI) based spectrometer has been developed for detecting the spectral signatures of eroding rocket engine components during ground tests and/or flight operations, with a view to use in future rocket engine health-management systems (HMSs). A flight-capable HMS will furnish prognoses and responses to incipient engine failures, as well as diagnoses of wear and degradation during maintenance. Attention is given to the development of a prototype FPI spectrometer for demonstration and validation testing at NASA-Marshall.

Bickford, R. L.↗

Self Diagnostic Accelerometer Ground Testing on a C-17 Aircraft Engine

The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. Sensor system malfunction is a significant contributor to propulsion in flight shutdowns (IFSD) which can lead to aircraft accidents when the issue is compounded with an inappropriate crew response. The development of the SDA is important for both reducing the IFSD rate, and hence reducing the rate at which this component failure type can put an aircraft in jeopardy, and also as a critical enabling technology for future automated malfunction diagnostic systems. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to making vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. In an effort toward demonstrating the SDAs flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The two SDA attachment conditions used were fully tight and loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first time the robustness of the SDA in an engine environment characterized by high vibration levels.

Tokars, Roger P.↗

Flight test summary of modified fuel systems

Two different aircraft designs, each with two modified fuel control systems, were evaluated. Each aircraft was evaluated in a given series of defined ground and flight conditions while quantitative and qualitative observations were made. During this program, some ten flights were completed, and a total of about 13 hours of engine run time was accumulated by the two airplanes. The results of these evaluations with emphasis on the operational and safety aspects were analyzed. Ground tests of the engine alone were not able to predict acceptable limiting lean mixture settings for the flight envelopes of the Cessna Models 150 and T337.

Barrett, B. G.↗

Full scale technology demonstration of a modern counterrotating unducted fan engine concept. Engine test

The Unducted Fan (UDF) engine is an innovative aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio power plant with exceptional fuel efficiency for subsonic aircraft application. This report covers the successful ground testing of this engine. A test program exceeding 100-hr duration was completed, in which all the major goals were achieved. The following accomplishments were demonstrated: (1) full thrust (25,000 lb); (2) full counterrotating rotor speeds (1393+ rpm); (3) low specific fuel consumption (less than 0.24 lb/hr/lb); (4) new composite fan design; (5) counterrotation of structures, turbines, and fan blades; (6) control system; (7) actuation system; and (8) reverse thrust.

Source record↗

SPRITE: A TPS Test Bed for Ground and Flight

Engineers in the Entry Systems and Technology Division at NASA Ames Research Center developed a fully instrumented, small atmospheric entry probe called SPRITE (Small Probe Reentry Investigation for TPS Engineering). SPRITE, conceived as a flight test bed for thermal protection materials, was tested at full scale in an arc-jet facility so that the aerothermal environments the probe experiences over portions of its flight trajectory and in the arc-jet are similar. This ground-to-flight traceability enhances the ability of mission designers to evaluate margins needed in the design of thermal protection systems (TPS) of larger scale atmospheric entry vehicles. SPRITE is a 14-inch diameter, 45 deg. sphere-cone with a conical aftbody and designed for testing in the NASA Ames Aerodynamic Heating Facility (AHF). The probe is a two-part aluminum shell with PICA (phenolic impregnated carbon ablator) bonded on the forebody and LI-2200 (Shuttle tile material) bonded to the aftbody. Plugs with embedded thermocouples, similar to those installed in the heat shield of the Mars Science Laboratory (MSL), and a number of distributed sensors are integrated into the design. The data from these sensors are fed to an innovative, custom-designed data acquisition system also integrated with the test article. Two identical SPRITE models were built and successfully tested in late 2010-early 2011, and the concept is currently being modified to enable testing of conformable and/or flexible materials.

Ablation↗

Algorithm Helps Monitor Engine Operation

Real-Time Failure Control (RTFC) algorithm part of automated monitoring-and-shutdown system being developed to ensure safety and prevent major damage to equipment during ground tests of main engine of space shuttle. Includes redundant sensors, controller voting logic circuits, automatic safe-limit logic circuits, and conditional-decision logic circuits, all monitored by human technicians. Basic principles of system also applicable to stationary powerplants and other complex machinery systems.

Eckerling, Sherry J.↗

Characteristics of Space Shuttle Main Engine failures

During development and operation of the Space Shuttle Main Engine (SSME), 27 ground test failures of sufficient severity to be termed 'major incident' have occurred. Resourecs including NASA Failure Investigation Board reports, contractor failure reports, originally recorded data, along with engineering notes, data bases, and presentations connected with the failures were available for compilation into the engine failure review presented in this paper. Most SSME failures were a result of design deficiencies stemming from inadequate definition of dynamic loads. High cycle fatigue was the most frequent mechanism leading to failure. Eighteen of the 27 failures occurred during constant power level operation. Formal board reports were not available for all failures. Therefore, the failure history presented in this paper is not complete or of uniform quality.

Cikanek, Harry A., III↗

Installation caused flow distortion and its effect on noise from a fan designed for turbofan engines.

Use of a ground test stand to obtain acoustic data on a full-scale prototype fan designed for quiet subsonic-aircraft engines. The fan was installed in three different ways in the test stand. In two of the installations the fan was driven by a shaft in the inlet; in the third installation the fan was driven from the rear. These three installations, and the structures associated with them, resulted in various amounts of inlet flow distortion to the fan. The rear-drive installation had less inlet flow distortion than the two front drive installations. Differences in blade passage sound pressure levels of more than 10 dB were measured between the rear-drive and front-drive versions, with the rear-drive installation producing less noise. Perceived noise levels were computed and the influence of the distortion on these levels was determined.

Povinelli, F. P.↗

Compact Analyzer/Controller For Oxygen-Enrichment System

System controls hypersonic air-breathing engine tests. Compact analyzer/controller developed, built, and tested in small-scale wind tunnel prototype of the 8' HTT (High-Temperature Tunnel). Monitors level of oxygen and controls addition of liquid oxygen to enrich atmosphere for combustion. Ensures meaningful ground tests of hypersonic engines in range of speeds from mach 4 to mach 7.

Puster, Richard L.↗

An inventory of aeronautical ground research facilities. Volume 2: Air breathing engine test facilities

The inventory covers free jet and direct connect altitude cells, sea level static thrust stands, sea level test cells with ram air, and propulsion wind tunnels. Free jet altitude cells and propulsion wind tunnels are used for evaluation of complete inlet-engine-exhaust nozzle propulsion systems under simulated flight conditions. These facilities are similar in principal of operation and differ primarily in test section concept. The propulsion wind tunnel provides a closed test section and restrains the flow around the test specimen while the free jet is allowed to expand freely. A chamber of large diameter about the free jet is provided in which desired operating pressure levels may be maintained. Sea level test cells with ram air provide controlled, conditioned air directly to the engine face for performance evaluation at low altitude flight conditions. Direct connect altitude cells provide a means of performance evaluation at simulated conditions of Mach number and altitude with air supplied to the flight altitude conditions. Sea level static thrust stands simply provide an instrumented engine mounting for measuring thrust at zero airspeed. While all of these facilities are used for integrated engine testing, a few provide engine component test capability.

Pirrello, C. J.↗

Ground Tests of a Radial Air-Cooled Engine to Correct a Poor Circumferential Pressure-Recovery Distribution

This report presents the results of the tests of a power-plant installation to improve the circumferential pressure-recovery distribution at the face of the engine. An underslung "C" cowling was tested with two propellers with full cuffs and with a modification to one set of cuffs. Little improvement was obtained because the base sections of the cuffs were stalled. A set of guide vanes boosted the over-all pressures and helped the pressure recoveries for a few of the cylinders. Making the underslung cowling into a symmetrical "C" cowling evened the pressure distribution; however, no increases in front pressures were obtained. The pressures at the top cylinders remained low and the high pressures at the bottom cylinders were reduced. At higher powers and engine speeds, the symmetrical cowling appeared best from the standpoint of over-all cooling characteristics.

Gallagher, James J.↗