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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 55 records · Page 3

CosmoQuest: Better Citizen Science Through Education

In the modern era, NASA SMD missions and facilities are producing data at a rate too great for the science community to maximally utilize. While software can help, what is really needed is additional eyes, hands, and minds - help we can find in the form of citizen scientist volunteers. The CosmoQuest virtual research facility has demonstrated through published research results that classroom students and the public can, with proper training and support from Subject Matter Experts (SMEs), fill roles more traditionally filled by university students. The research question behind CosmoQuest's creation was simple: if students and the public are provided a properly scaffolded experience that mirrors that of researchers, will they come and perform as well as our students? and can they rise up to be research collaborators? In creating CosmoQuest, we started with a core of citizen science portals, educational materials for both students and life-long learners, and collaboration areas. These three primary focuses mirror the research, courses, and collaboration spaces that form the foundation of a university department. We then went on to add the features that make a center stand out - we added seminars in the form of Google Hangouts on Air, planetarium content through our Science on the Half Sphere program, and even the chance to vicariously attend conferences through live blogging by our team members. With this design for a virtual research facility, the answer to our foundational question has been a resounding yes; the public can aid us in doing science provided they are properly trained. To meet the needs of our population we have developed four areas of engagement: research, education, media, and community.

Gay, P. L.

The high Reynolds number cryogenic wind tunnel.

Theoretical considerations indicate that cooling the wind-tunnel test gas to cryogenic temperatures will provide a large increase in test Reynolds number with no increase in dynamic pressure while reducing the tunnel drive-power requirements. Studies have been made to determine the expected variations of Reynolds number and other parameters over wide ranges of Mach number, pressure, and temperature with due regard to avoiding liquefaction and adverse real-gas effects. Practical operational procedures have been developed in a low-speed prototype cryogenic wind tunnel. Aerodynamic experiments in the facility have demonstrated the theoretically predicted variations in Reynolds number and drive power. Force and moment measurements on a wing model mounted on a water-jacketed strain-gage sting balance have demonstrated the feasibility of operation of such balances in a cryogenic environment.

Goodyer, M. J.

Operation of small rocket engines in the JPL high-vacuum molecular space simulator (Molsink)

The feasibility of operating small rocket engines in the Molsink facility was demonstrated. A 0.44-N (0.1-lbf) hydrazine engine and a 0.18-N (0.04-lbf) thruster using cold gas from a hydrazine plenum system were operated for both flight duty cycles and off-nominal conditions. The exhaust gases from these thrusters contain NH3, N2, and H2. The chamber was also calibrated for larger bipropellant engines using nitrogen tetroxide/monomethyl hydrazine (NTO/MMH). The exhaust products of these engines contain CO2, CO, H2, H2O, and H2. A mixture of cold gases simulating the engine exhaust was injected through a nozzle under conditions simulating thrust levels up to 26.7-N (6 lbf). Pulsing and continuous operations were investigated. The chamber background pressure traces were compared with the traces obtained for the same thrusters operated with pure nitrogen at approximately equivalent thrust. Satisfactory recuperation times were encountered in all the pulsing modes. Test times greater than 20s were obtained in steady state operation before the vacuum chamber back pressure climbed to prohibitive values.

Chirivella, J. E.

Inspection of composites using a computer-based real-time radiographic facility

A radiographic inspection facility was developed at the NASA Lewis Research Center. The facility uses a digital computer to provide enhanced images in near real-time. Some capabilities of the facility are demonstrated in the inspection of a fan frame ring for an experimental aircraft gas turbine. The ring was fabricated from a carbon-fiber-reinforced epoxy composite material. Inspection procedures were evaluated, and comparisons were made with an ultrasonic C-scan and conventional film X-ray.

Roberts, E., Jr.

Stage efficiency in the analysis of thermochemical water decomposition processes

The procedure for analyzing thermochemical water-splitting processes using the figure of merit is expanded to include individual stage efficiencies and loss coefficients. The use of these quantities to establish the thermodynamic insufficiencies of each stage is shown. A number of processes are used to illustrate these concepts and procedures and to demonstrate the facility with which process steps contributing most to the cycle efficiency are found. The procedure allows attention to be directed to those steps of the process where the greatest increase in total cycle efficiency can be obtained.

Conger, W. L.

Oral presentation of first year final report, appendix A

Plans for self contained in-house capability to test Large Space Structures (LSS) and their control prior to flight are presented. A ground test facility which demonstrates and validates LSS control theory is defined. An experiment is designed which assures a high success rate for flight test. A strapdown algorithm is developed. Research on the astromast is reported, as is the development of an overall system model.

Source record

Advancements in oxygen generation and humidity control by water vapor electrolysis

Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

Heppner, D. B.

Cryogenic, high speed, turbopump bearing cooling requirements

Although the Space Shuttle Main Engine (SSME) has repeatedly demonstrated the capability to perform during launch, the High Pressure Oxidizer Turbopump (HPOTP) main shaft bearings have not met their 7.5 hour life requirement. A tester is being employed to provide the capability of subjecting full scale bearings and seals to speeds, loads, propellants, temperatures, and pressures which simulate engine operating conditions. The tester design permits much more elaborate instrumentation and diagnostics than could be accommodated in an SSME turbopump. Tests were made to demonstrate the facilities; and the devices' capabilities, to verify the instruments in its operating environment and to establish a performance baseline for the flight type SSME HPOTP Turbine Bearing design. Bearing performance data from tests are being utilized to generate: (1) a high speed, cryogenic turbopump bearing computer mechanical model, and (2) a much improved, very detailed thermal model to better understand bearing internal operating conditions. Parametric tests were also made to determine the effects of speed, axial loads, coolant flow rate, and surface finish degradation on bearing performance.

Dolan, Fred J.

An update of engine system research at the Army Propulsion Directorate

The Small Turboshaft Engine Research (STER) program provides a vehicle for evaluating the application of emerging technologies to Army turboshaft engine systems and to investigate related phenomena. Capitalizing on the resources at hand, in the form of both the NASA facilities and the Army personnel, the program goal of developing a physical understanding of engine system dynamics and/or system interactions is being realized. STER entries investigate concepts and components developed both in-house and out-of-house. Emphasis is placed upon evaluations which have evolved from on-going basic research and advanced development programs. Army aviation program managers are also encouraged to make use of STER resources, both people and facilities. The STER personnel have established their reputations as experts in the fields of engine system experimental evaluations and engine system related phenomena. The STER facility has demonstrated its utility in both research and development programs. The STER program provides the Army aviation community the opportunity to perform system level investigations, and then to offer the findings to the entire engine community for their consideration in next generation propulsion systems. In this way results of the fundamental research being conducted to meet small turboshaft engine technology challenges expeditiously find their way into that next generation of propulsion systems.

Bobula, George A.

Results from the LDEF/A0076 cascaded variable conductance heatpipe experiment

The A0076 Variable Conductance Heat Pipe Experiment (CVCHPE) on the Long Duration Exposure Facility (LDEF) demonstrated temperature control better than +/- 0.3 C during fifty days on on-orbit data collection in a widely varying external environment. The experiment used two series connected, dry reservoir variable conductance heat pipes which require no electrical power for operation. The heat pipes used a central artery design with ammonia working fluid and nitrogen control gas. The LDEF was in orbit for almost six years rather than the planned one year mission. Although no additional data were taken during this extended period, post-test data indicated that the set point drifted upward less than 1 C per year. There were significant changes to the appearance of all external thermal control surfaces primarily due to atomic oxygen degradation, and one small anomaly in the electronics. These changes, though, had little effect on the CVCHPE performance.

Grote, Michael G.

Linear Spectral Analysis of Plume Emissions Using an Optical Matrix Processor

Plume spectrometry provides a means to monitor the health of a burning rocket engine, and optical matrix processors provide a means to analyze the plume spectra in real time. By observing the spectrum of the exhaust plume of a rocket engine, researchers have detected anomalous behavior of the engine and have even determined the failure of some equipment before it would normally have been noticed. The spectrum of the plume is analyzed by isolating information in the spectrum about the various materials present to estimate what materials are being burned in the engine. Scientists at the Marshall Space Flight Center (MSFC) have implemented a high resolution spectrometer to discriminate the spectral peaks of the many species present in the plume. Researchers at the Stennis Space Center Demonstration Testbed Facility (DTF) have implemented a high resolution spectrometer observing a 1200-lb. thrust engine. At this facility, known concentrations of contaminants can be introduced into the burn, allowing for the confirmation of diagnostic algorithms. While the high resolution of the measured spectra has allowed greatly increased insight into the functioning of the engine, the large data flows generated limit the ability to perform real-time processing. The use of an optical matrix processor and the linear analysis technique described below may allow for the detailed real-time analysis of the engine's health. A small optical matrix processor can perform the required mathematical analysis both quicker and with less energy than a large electronic computer dedicated to the same spectral analysis routine.

Gary, C. K.

Balloon Fuel Cell Power System

NASA Lewis Research Center's Electrochemical Technology Branch has teamed with the NASA Wallops Flight Facility to demonstrate the operation of a hydrogen-oxygen proton exchange membrane (PEM) fuel cell for application in the upper atmosphere. NASA Wallops' Balloon Programs Branch has a requirement for a high-power, long-duration power system for use on a scientific balloon platform. The current power system will not meet these needs. The objective of this program is to deliver a 200-W (minimum) fuel cell system that can deliver approximately 10 kWh of electrical energy.

Source record

Zero Boiloff Storage of Cryogenic Propellants Achieved at Lewis' Supplemental Multilayer Insulation Research Facility

Tests conducted at the NASA Lewis Research Center's Supplemental Multilayer Insulation Research Facility (SMIRF) demonstrated that a hybrid thermal control system could eliminate boiloff of cryogenic propellants. This is significant because of the substantial mass and cost savings that could be achieved for any long-duration space mission that requires cryogenic propellants. With long-duration cryogenic storage, propellants will boil off because of the environmental heating of the tank. To accommodate these losses, extra propellant is required along with larger propellant tanks. Analysis of Mars mission scenarios using space-transfer cryogenic stages showed that significant savings in propellant mass and tank size could be achieved if it were possible to eliminate or significantly reduce propellant boiloff. Engineers and technicians at NASA Lewis designed, built, and tested a hybrid thermal control system to eliminate or significantly reduce cryogenic propellant boiloff. The system consists of an active cryocooling system using a cryocooler in addition to the traditional passive thermal insulation, as shown in the photo.

Plachta, David W.

Aerodynamic Performance and Acoustic Measurements of a High-Lift Propeller in an Isolated Configuration

A series of aerodynamic performance and acoustic measurements has been made on a high-lift propeller intended for utilization on a distributed electric propulsion (DEP) aircraft. Tests were performed in the NASA Langley Low Speed Aeroacoustic Wind Tunnel (LSAWT), which has recently undergone a capability enhancement for the testing of small propellers/rotors and small unmanned aircraft system (UAS) platforms. The objectives of this testing campaign are two-fold: first to demonstrate the facility capabilities for performing small propeller aeroacoustic testing, and second to compare experimental measurements with computational fluid dynamic (CFD) predictions and CFD-based acoustic predictions of the tested propeller configurations for tool development and validation purposes.

Zawodny, Nikolas S.

Hypersonic Boundary-Layer Transition on Blunted Cones at Angle of Attack

Experimental studies of cones at several high-speed facilities have demonstrated that, for small nosetip bluntness, transition onset over a circular cone moves upstream along the leeward side and downstream along the windward side, but this trend may be reversed at large bluntness values, where transition onset moves downstream along the leeward side and upstream along the windward side. A theoretical and numerical investigation is performed to characterize the effects of nose bluntness on disturbance amplification over the circular cone for several angles of attack, with the goal of understanding the potential physical mechanisms behind the experimental observations. The three-dimensional laminar basic states over a 1.5 m long, 7-degree half-angle cone with 9.525 mm nosetip radius are computed for selected angles of attack values and freestream conditions that are selected to match the Mach 10 experiments conducted within the Hypervelocity Wind Tunnel 9 at the Arnold Engineering Development Complex (AEDC). The solutions at a freestream unit Reynolds number of 17.1 million per meter are used to perform detailed instability analyses for angles of attack equal to 0, 1, 3, and 5 degrees. Results indicate that the linear amplification of stationary crossflow waves along inflection lines may begin to influence transition along the acreage of the cone for angles of attack equal to or larger than 5 degrees. The measured trend in transition front with respect to increasing angle of attack is found to be consistent with the predicted increase in the amplification factors for Mack mode disturbances along the streamline trajectories. The increase in Mack mode amplification along the windward ray for higher angles of attack is shown to be the result of a progressively earlier entropy-layer swallowing. Computations also indicate that the transition amplification factor along the windward ray is not constant and increases with the angle of attack and that the transition #-factors along the leeward ray are rather small. The nonmodal analysis for zero degrees angle of attack shows that entropy-layer disturbances with appreciably strong energy growth can coexist with Mack mode instabilities at the measured transition location.

boundary layer transition

Hypersonic Boundary-Layer Transition on Blunted Cones at Angle of Attack

Experimental studies of cones at several high-speed facilities have demonstrated that, for small nosetip bluntness, transition onset over a circular cone moves upstream along the leeward side and downstream along the windward side, but this trend may be reversed at large bluntness values, where transition onset moves downstream along the leeward side and upstream along the windward side. A theoretical and numerical investigation is performed to characterize the effects of nose bluntness on disturbance amplification over the circular cone for several angles of attack, with the goal of understanding the potential physical mechanisms behind the experimental observations. The three-dimensional laminar basic states over a 1.5 m long, 7-degree half-angle cone with 9.525 mm nosetip radius are computed for selected angles of attack values and freestream conditions that are selected to match the Mach 10 experiments conducted within the Hypervelocity Wind Tunnel 9 at the Arnold Engineering Development Complex (AEDC). The solutions at a freestream unit Reynolds number of 17.1 million per meter are used to perform detailed instability analyses for angles of attack equal to 0, 1, 3, and 5 degrees. Results indicate that the linear amplification of stationary crossflow waves along inflection lines may begin to influence transition along the acreage of the cone for angles of attack equal to or larger than 5 degrees. The measured trend in transition front with respect to increasing angle of attack is found to be consistent with the predicted increase in the amplification factors for Mack mode disturbances along the streamline trajectories. The increase in Mack mode amplification along the windward ray for higher angles of attack is shown to be the result of a progressively earlier entropy-layer swallowing. Computations also indicate that the transition amplification factor along the windward ray is not constant and increases with the angle of attack and that the transition #-factors along the leeward ray are rather small. The nonmodal analysis for zero degrees angle of attack shows that entropy-layer disturbances with appreciably strong energy growth can coexist with Mack mode instabilities at the measured transition location.

Boundary Layer Transition