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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Application of optical interferometry in compressible flows

Interferometry methods were applied to the investigation of steady and unsteady flows in large scale transonic wind tunnels. Holographic interferometry was demonstrated to provide reliable flow visualization and quantitative results for a number of two-dimensional flows. These conclusions were based on extensive comparisons with results obtained by other means. Data obtained on a NACA 64A010 airfoil with an oscillating flap installed in the Ames 11-foot transonic tunnel are presented. Interferograms were recorded at a free stream Mach number of 0.8, flap frequency of 30 Hertz and chord Reynolds numbers of 6.6 x 10 to the 6th and 12.3 x 10 to the 6th. The interferometric results were reduced to dynamic surface pressures, Mach contours and wake flow profiles. A new interferometry method that is capable of providing real-time interferometry data is also discussed.

Bachalo, W. D.↗
NASA NTRS1987

The 737 graphite composite flight spoiler flight service evaluation

The ninth flight service report was prepared in compliance with the requirements of Contract NAS1-11668. It covers the flight service experience of 111 graphite-epoxy spoilers on 737 transport aircraft and related ground-based environmental exposure of graphite epoxy material specimens for the period 1 Jan. 1985 through 31 Dec. 1986. Spoilers have been installed on 28 aircraft representing seven major airlines operating throughout the world. An extended flight service evaluation program of 15 years is presently underway. As of 31 Dec. 1986, a total of 3,339,608 spoiler flight-hours and 3,320,952 spoiler landings had been accumulated by this fleet.

Coggeshall, Randy L.↗
NASA NTRS1987

Overview of NASA PTA propfan flight test program

During the last several years high-speed propellers have made the transition from a wind tunnel curiosity to a very likely near-term, fuel-efficient propulsion system that could revolutionize the subsonic commercial air transport industry. A key ingredient in this remarkable progress is the advanced turboprop industry. Working together, NASA and industry have developed and flight tested two propeller propulsion systems to provide answers to key technical questions and concerns. An industry team is currently developing a third propeller propulsion system for flight testing late this year. The progress of one of the NASA-industry flight test programs, called the Propfan Test Assessment (PTA) Program is reported. In PTA, a 9 foot diameter propfan was installed on the left wing of a Gulfstream GII executive jet and is undergoing extensive flight testing at Dobbins Air Force Base to evaluate propfan structural integrity, near and far field noise, and cabin interior noise characteristics. This research testing includes variations in propeller tip speed and power loading, nacelle tilt angle, and aircraft Mach number and altitude. As a result, extensive parametric data will be obtained to verify and improve computer codes for predicting propeller structural aeroelastic, aerodynamic, and acoustic characteristics. Over 600 measurements are being recorded for each of approximately 600 flight test conditions.

Graber, Edwin J.↗
NASA NTRS1996

Off-the-shelf real-time monitoring of satellite constellations in a visual 3-D environment

The multimission spacecraft analysis system (MSAS) data monitor is a generic software product for future real-time data monitoring and analysis. The system represents the status of a satellite constellation through the shape, color, motion and position of graphical objects floating in a three dimensional virtual reality environment. It may be used for the monitoring of large volumes of data, for viewing results in configurable displays, and for providing high level and detailed views of a constellation of monitored satellites. It is considered that the data monitor is an improvement on conventional graphic and text-based displays as it increases the amount of data that the operator can absorb in a given period, and can be installed and configured without the requirement for software development by the end user. The functionality of the system is described, including: the navigation abilities; the representation of alarms in the cybergrid; limit violation; real-time trend analysis, and alarm status indication.

Schwuttke, Ursula M.↗
NASA NTRS1998

Flight Testing the Linear Aerospike SR-71 Experiment (LASRE)

The design of the next generation of space access vehicles has led to a unique flight test that blends the space and flight research worlds. The new space vehicle designs, such as the X-33 vehicle and Reusable Launch Vehicle (RLV), are powered by linear aerospike rocket engines. Conceived of in the 1960's, these aerospike engines have yet to be flown, and many questions remain regarding aerospike engine performance and efficiency in flight. To provide some of these data before flying on the X-33 vehicle and the RLV, a spacecraft rocket engine has been flight-tested atop the NASA SR-71 aircraft as the Linear Aerospike SR-71 Experiment (LASRE). A 20 percent-scale, semispan model of the X-33 vehicle, the aerospike engine, and all the required fuel and oxidizer tanks and propellant feed systems have been mounted atop the SR-71 airplane for this experiment. A major technical objective of the LASRE flight test is to obtain installed-engine performance flight data for comparison to wind-tunnel results and for the development of computational fluid dynamics-based design methodologies. The ultimate goal of firing the aerospike rocket engine in flight is still forthcoming. An extensive design and development phase of the experiment hardware has been completed, including approximately 40 ground tests. Five flights of the LASRE and firing the rocket engine using inert liquid nitrogen and helium in place of liquid oxygen and hydrogen have been successfully completed.

Stephen Corda↗
NASA NTRS2015

Evaluation of MEMS-Based Wireless Accelerometer Sensors in Detecting Gear Tooth Faults in Helicopter Transmissions

The diagnostics capability of micro-electro-mechanical systems (MEMS) based rotating accelerometer sensors in detecting gear tooth crack failures in helicopter main-rotor transmissions was evaluated. MEMS sensors were installed on a pre-notched OH-58C spiral-bevel pinion gear. Endurance tests were performed and the gear was run to tooth fracture failure. Results from the MEMS sensor were compared to conventional accelerometers mounted on the transmission housing. Most of the four stationary accelerometers mounted on the gear box housing and most of the CI's used gave indications of failure at the end of the test. The MEMS system performed well and lasted the entire test. All MEMS accelerometers gave an indication of failure at the end of the test. The MEMS systems performed as well, if not better, than the stationary accelerometers mounted on the gear box housing with regards to gear tooth fault detection. For both the MEMS sensors and stationary sensors, the fault detection time was not much sooner than the actual tooth fracture time. The MEMS sensor spectrum data showed large first order shaft frequency sidebands due to the measurement rotating frame of reference. The method of constructing a pseudo tach signal from periodic characteristics of the vibration data was successful in deriving a TSA signal without an actual tach and proved as an effective way to improve fault detection for the MEMS.

gears↗
NASA NTRS2015

Force Limited Random Vibration Test of TESS Camera Mass Model

The Transiting Exoplanet Survey Satellite (TESS) is a spaceborne instrument consisting of four wide field-of-view-CCD cameras dedicated to the discovery of exoplanets around the brightest stars. As part of the environmental testing campaign, force limiting was used to simulate a realistic random vibration launch environment. While the force limit vibration test method is a standard approach used at multiple institutions including Jet Propulsion Laboratory (JPL), NASA Goddard Space Flight Center (GSFC), European Space Research and Technology Center (ESTEC), and Japan Aerospace Exploration Agency (JAXA), it is still difficult to find an actual implementation process in the literature. This paper describes the step-by-step process on how the force limit method was developed and applied on the TESS camera mass model. The process description includes the design of special fixtures to mount the test article for properly installing force transducers, development of the force spectral density using the semi-empirical method, estimation of the fuzzy factor (C2) based on the mass ratio between the supporting structure and the test article, subsequent validating of the C2 factor during the vibration test, and calculation of the C.G. accelerations using the Root Mean Square (RMS) reaction force in the spectral domain and the peak reaction force in the time domain.

Karlicek, Alexandra↗
NASA NTRS2024

Paint and Oil Locker SWMU 067 Southern Treatment Area Air Sparge System Year 2 Performance Monitoring and Paint and Oil Locker Northern Area (SWMU 067) and Supply Warehouse #3, SWMU 088 Long-Term Monitoring Kennedy Space Center, Florida

This Year 2 Air Sparge (AS) System Performance Monitoring (PM) Report for Paint and Oil Locker (POL) Solid Waste Management Unit (SWMU) 067 Southern Treatment Area and Long- Term Monitoring (LTM) Report for POL Northern Area (SWMU 067) and Supply Warehouse #3 (SW3) SWMU 088 documents ongoing remedial efforts at the POL and SW3 sites at Kennedy Space Center (KSC), Florida. The overall goal for these sites is to reduce concentrations of groundwater contaminants of concern (COCs), specifically trichloroethene (TCE), cis-1,2-dichloroethene (cDCE), trans-1,2-dichloroethene (tDCE) and vinyl chloride (VC), to below the State of Florida Groundwater Cleanup Target Levels (GCTLs). Remediation and reporting of POL and SW3 have been streamlined over the years due to the proximity of the two sites. The scope for these sites currently includes two main components: (1) LTM at SW3 and the POL Northern Area, where an AS system began operation in May 2009 (with expansion in December 2012) and June 2013, respectively, and subsequently turned off for both sites in March 2018 (NASA, 2019a); and (2) Active AS operations and PM in the POL Southern Treatment Area where an AS system was installed and began operation in 2021. The timeframe for activities covered under this report is from September 2022 to July 2023. Based on Year 2 system operation and PM results, the AS system at POL operated as designed and successfully met the performance objective of reducing VOCs to concentrations that support transition of the site from active remediation to long-term monitoring. The results from the samples collected from performance monitoring wells within the AS system ROI showed a significant decrease in COC concentrations since the baseline sampling event conducted in April 2020. Based on the Year 2 OM&M and monitoring results obtained from the POL Southern Treatment Area, the IM objective to reduce concentrations to below the LTM transition target concentrations for TCE, cDCE, tDCE, and VC has been achieved. LTM sampling events at SW3 were conducted in October 2022 and July 2023. LTM sampling was conducted at the POL Northern Area in October 2022, December 2022, March 2023, and July 2023. Analytical results from October 2022 and July 2023 generally indicate that concentrations of COCs have been stable or decreasing compared to the previous year. TCE remains greater than the NADC in one monitoring well (POL-MW0034S) and greater than the GCTL in one monitoring well (POL-MW0009S). Concentrations of cDCE were greater than the GCTL in one monitoring well (POL-MW0026S), and tDCE was non-detect or less than the GCTL in all monitoring wells sampled. VC was greater than the GCTL in four monitoring wells (MW0024, MW0025, MW0027, and MW0028) at SW3 and one monitoring well (MW0026S) at the POL Northern Area.

remediation↗
NASA NTRS2017

Viscous Aerodynamic Shape Optimization with Installed Propulsion Effects

Aerodynamic shape optimization is demonstrated to tailor the under-track pressure signature of a conceptual low-boom supersonic aircraft. Primarily, the optimization reduces nearfield pressure waveforms induced by propulsion integration effects. For computational efficiency, gradient-based optimization is used and coupled to the discrete adjoint formulation of the Reynolds-averaged Navier Stokes equations. The engine outer nacelle, nozzle, and vertical tail fairing are axi-symmetrically parameterized, while the horizontal tail is shaped using a wing-based parameterization. Overall, 48 design variables are coupled to the geometry and used to deform the outer mold line. During the design process, an inequality drag constraint is enforced to avoid major compromise in aerodynamic performance. Linear elastic mesh morphing is used to deform volume grids between design iterations. The optimization is performed at Mach 1.6 cruise, assuming standard day altitude conditions at 51,707-ft. To reduce uncertainty, a coupled thermodynamic engine cycle model is employed that captures installed inlet performance effects on engine operation.

computational fluid dynamics↗
NASA NTRS1980

Solar energy system economic evaluation: IBM System 2, Togus, Maine

The economic analysis of the solar energy system, is developed for Torgus and four other sites typical of a wide range of environmental and economic conditions in the continental United States. This analysis is accomplished based on the technical and economic models in the f-chart design procedure with inputs taken on the characteristics of the installed system and local conditions. The results are expressed in terms of the economic parameters of present worth of system cost over a projected twenty year life, life cycle savings, year of positive savings and year of payback for the optimized solar energy system at each of the analysis sites. The sensitivity of the economic evaluation to uncertainties in constituent system and economic variables is also investigated. Results demonstrate that the solar energy system is economically viable at all of the five sites for which the analysis was conducted.

Source record↗
NASA NTRS1980

Low cost solar array project: Experimental process system development unit for producing semiconductor-grade silicon using silane-to-silicon process

The design, fabrication, and installation of an experimental process system development unit (EPSDU) were analyzed. Supporting research and development were performed to provide an information data base usable for the EPSDU and for technological design and economical analysis for potential scale-up of the process. Iterative economic analyses were conducted for the estimated product cost for the production of semiconductor grade silicon in a facility capable of producing 1000-MT/Yr.

Source record↗
NASA NTRS1981

Parabolic dish systems at work - Applying the concepts

An overview is given of parabolic dish solar concentrator application experiments being conducted by the U.S. Department of Energy. The 'engineering experiments' comprise the testing of (1) a small-community powerplant system, in conjunction with a grid-connected utility; (2) stand-alone applications at remote sites such as military installations, radar stations and villages; and (3) dish modules that can deliver heat for direct use in industrial processes. Applicability projections are based on a dish and receiver that use a Brayton engine with an engine/generator efficiency of 25% and a production level of up to 25,000 units per year. Analyses indicate that parabolic-dish power systems can potentially replace small, oil-fired power plants in all regions of the U.S. between 1985 and 1991.

Marriott, A. T.↗
NASA NTRS1990

Wind shear predictive detector technology study status

Among the different elements to be investigated when considering the Wind Shear hazard, the Aeronautical Navigation Technical Service (STNA/3E), whose task is to participate in the development of new technologies and equipments, focused its effort on airborne and ground sensors for the detection of low-level wind shear. The first task, initiated in 1986, consists in the evaluation of three candidate techniques for forward-looking sensors: lidar, sodar, and radar. No development is presently foreseen for an infrared based air turbulence advance warning system although some flight experiments took place in the 70's. A Thomson infrared radiometer was then installed on an Air France Boeing 707 to evaluate its capability of detecting clear air turbulence. The conclusion showed that this technique was apparently able to detect cloud layers but that additional experiments were needed; on the other hand, the rarity of the phenomenon and the difficulty in operating on a commercial aircraft were also mentioned.

Gandolfi, C.↗
NASA NTRS2002

STS-111 Flight Day 5 Highlights

On Flight Day 5 of STS-111, the crew of Endeavour (Kenneth Cockrell, Commander; Paul Lockhart, Pilot; Franklin Chang-Diaz, Mission Specialist; Philippe Perrin, Mission Specialist) and the Expedition 5 crew (Valery Korzun, Commander; Peggy Whitson, Flight Engineer; Sergei Treschev, Flight Engineer) and Expedition 4 crew (Yury Onufrienko, Commander; Daniel Bursch, Flight Engineer; Carl Walz, Flight Engineer) are aboard the docked Endeavour and International Space Station (ISS). The ISS cameras show the station in orbit above the North African coast and the Mediterranean Sea, as Chang-Diaz and Perrin prepare for an EVA (extravehicular activity). The Canadarm 2 robotic arm is shown in motion in a wide-angle shot. The Quest Airlock is shown as it opens to allow the astronauts to exit the station. As orbital sunrise approaches, the astronauts are shown already engaged in their EVA activities. Chang-Diaz is shown removing the PDGF (Power and Data Grapple Fixture) from Endeavour's payload bay as Perrin prepares its installation position in the ISS's P6 truss structure; The MPLM is also visible. Following the successful detachment of the PDGF, Chang-Diaz carries it to the installation site as he is transported there by the robotic arm. The astronauts are then shown installing the PDGF, with video provided by helmet-mounted cameras. Following this task, the astronauts are shown preparing the MBS (Mobile Base System) for grappling by the robotic arm. It will be mounted to the Mobile Transporter (MT), which will traverse a railroad-like system along the truss structures of the ISS, and support astronaut activities as well as provide an eventual mobile base for the robotic arm.

Source record↗
NASA NTRS2015

Design and Test of a Liquid Oxygen / Liquid Methane Thruster with Cold Helium Pressurization Heat Exchanger

A liquid oxygen / liquid methane 2,000 lbf thruster was designed and tested in conjuction with a nozzle heat exchanger for cold helium pressurization. Cold helium pressurization systems offer significant spacecraft vehicle dry mass savings since the pressurant tank size can be reduced as the pressurant density is increased. A heat exchanger can be incorporated into the main engine design to provide expansion of the pressurant supply to the propellant tanks. In order to study the systems integration of a cold-helium pressurization system, a 2,000 lbf thruster with a nozzle heat exchanger was designed for integration into the Project Morpheus vehicle at NASA Johnson Space Center. The testing goals were to demonstrate helium loading and initial conditioning to low temperatures, high-pressure/low temperature storage, expansion through the main engine heat exchanger, and propellant tank injection/pressurization. The helium pressurant tank was an existing 19 inch diameter composite-overwrap tank, and the targert conditions were 4500 psi and -250 F, providing a 2:1 density advantage compared to room tempatrue storage. The thruster design uses like-on-like doublets in the injector pattern largely based on Project Morpheus main engine hertiage data, and the combustion chamber was designed for an ablative chamber. The heat exchanger was installed at the ablative nozzle exit plane. Stand-alone engine testing was conducted at NASA Stennis Space Center, including copper heat-sink chambers and highly-instrumented spoolpieces in order to study engine performance, stability, and wall heat flux. A one-dimensional thermal model of the integrated system was completed. System integration into the Project Morpheus vehicle is complete, and systems demonstrations will follow.

Melcher, John C.↗
NASA NTRS2018

Wave-Front Error Measurements and Alignment of CLASP2 Telescope with a Dual-Band Pass Cold Mirror Coated Primary Mirror

"Chromospheric LAyer Spectro-Polarimeter (CLASP2)" is the next sounding rocket experiment of the "Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)" that succeeded in observing for the first time the linear polarization spectra in the hydrogen Lyman- line (121.6 nm) and is scheduled to be launched in 2019. In CLASP2, we will carry out full Stokes-vector spectropolarimetric observations in the Mg II h & k lines near 280 nm with the spectro-polarimeter (SP), while imaging observations in the Lyman- line will be conducted with the slitjaw optics (SJ). For the wavelength selection of CLASP2, the primary mirror of the telescope uses a new dual-band pass cold mirror coating targeting both at 121.6 nm and 280 nm. Therefore, we have to perform again the alignment of the telescope after the installation of the recoated primary mirror. Before unmounting the primary mirror from the telescope structure, we measured the wave-front error (WFE) of the telescope. The measured WFE map was consistent with what we had before the CLASP flight, clearly indicating that the telescope alignment has been maintained even after the flight. After the re-coated primary mirror was installed the WFE was measured, and coma aberration was found to be larger. Finally, the secondary mirror shim adjustments were carried out based on the WFE measurements. In CLASP2 telescope, we improved a fitting method of WFE map (applying 8th terms circular Zernike polynomial tting instead of 37th terms circular Zernike fitting) and the improved method enables to achieve better performance than CLASP telescope. Indeed, WFE map obtained after the final shim adjustment indicated that the required specification (< 5:5 m RMS spot radius) that is more stringent than CLASP telescope was met.

chromosphere; polarimetry; sounding rocket↗
NASA NTRS2019

Electrochemical Solutions for Advanced Life Support

The Oxygen Generating Assembly (OGA) on-board the International Space Station (ISS) employs a polymer electrolyte membrane (PEM) water electrolysis cell stack to electrochemically dissociate water into its two components – oxygen and hydrogen. Oxygen is provided to the cabin atmosphere for crew respiration while the hydrogen is delivered to a carbon dioxide reduction system to recover oxygen as water. The design of the OGA evolved over a number of years to arrive at the system solution that is currently operational on ISS. Future manned missions to space will require advanced technologies that eliminate the need for resupply from earth and feature in-situ resource utilization to sustain crew life and to provide useful materials to the crew. The architects planning such missions should consider all potential solutions at their disposal to arrive at an optimal vehicle solution that minimizes crew maintenance time, launch weight, installed volume and energy consumption demands. Skyre is developing new technologies through funding from NASA, the Department of Energy, and internal investment based on PEM technology that could become an integral part of these new vehicle solutions. At varying stages of Technology Readiness Level (TRL) are: an oxygen concentrator and compressor that can separate oxygen from an air stream and provide an enriched oxygen resource for crew medical use and space suit recharge without any moving parts in the pure oxygen stream; a regenerative carbon dioxide removal system featuring a PEM-based sorbent regenerator; a carbon dioxide reduction system that electrochemically produces organic compounds that could serve as fuels or as a useful intermediary to more beneficial compounds; and an electrochemical hydrogen separator and compressor for hydrogen recycle. The technical maturity of these projects is presented along with pertinent performance test data that could be beneficial in future study efforts.

Roy, Robert J.↗
NASA NTRS1992

An 8-DOF dual-arm system for advanced teleoperation performance experiments

This paper describes the electro-mechanical and control features of an 8-DOF manipulator manufactured by AAI Corporation and installed at the Jet Propulsion Lab. (JPL) in a dual-arm setting. The 8-DOF arm incorporates a variety of features not found in other lab or industrial manipulators. Some of the unique features are: 8-DOF revolute configuration with no lateral offsets at joint axes; 1 to 5 payload to weight ratio with 20 kg (44 lb) payload at a 1.75 m (68.5 in.) reach; joint position measurement with dual relative encoders and potentiometer; infinite roll of joint 8 with electrical and fiber optic slip rings; internal fiber optic link of 'smart' end effectors; four-axis wrist; graphite epoxy links; high link and joint stiffness; use of an upgraded JPL Universal Motor Controller (UMC) capable of driving up to 16 joints. The 8-DOF arm is equipped with a 'smart' end effector which incorporates a 6-DOF forcemoment sensor at the end effector base and grasp force sensors at the base of the parallel jaws. The 8-DOF arm is interfaced to a 6 DOF force reflecting hand controller. The same system is duplicated for and installed at NASA-Langley.

Bejczy, Antal K.↗