SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Development of auxiliary electric power generation system for hydrogen-oxygen spacecraft - redesign of oxygen injector and first stage cylinder head
Semiempirical potential energy surface generation for triatomic hydrogen from London equation by evaluating Coulomb and exchange integrals taking into account effective orbital overlap
Solid polymer electrolyte technology in a water electrolysis system along with ancillary components to generate oxygen and hydrogen for a manned space station application are considered. Standard commercial components are utilized wherever possible. Presented are the results of investigations, surveys, tests, conclusions and recommendations for future development efforts.
Requirements for the orbit transfer vehicle engine were examined. Engine performance/weight sensitivities, the effect of a service life of 300 start/shutdown cycles between overalls on the maximum engine operating pressure, and the sensitivity of the engine design point (i.e., thrust chamber pressure and nozzle area ratio) to the performance requirements specified are among the factors studied. Preliminary engine systems analyses were conducted on the stage combustion, expander, and gas generator engine cycles. Hydrogen and oxygen pump discharge pressure requirements are shown for various engine cycles. Performance of the engine cycles is compared.
A parallel-burn version of a single-stage vehicle for transport from the earth to low-earth orbit using two fuels and rocket propulsion is considered. New engine results were incorporated in vehicle performance and design studies. The results indicate that a hydrogen-cooled gas generator cycle engine provides attractive vehicle performance and that there is little incentive for increasing the chamber pressure beyond 27 MPa.
Simple aerosol generator catalytically converts hydrogen peroxide to super-heated steam and then mixes steam with dye. Highly visible mist lasts for 6 minutes and can be used to study aerodynamic turbulence. Method does not depend on formation of ice crystals at cold high altitudes and is environmentally safe.
Continuously operating compressor system converts 90 percent of gas-turbine plant energy to electricity. Conventional plants work in batch mode, operating at 40 percent efficiency. Compressor uses metal hydride matrix on outside of rotating drum to generate working gas, hydrogen. Rolling valve seals allow continuous work. During operation, gas is absorbed, releasing heat, and desorbed with heat gain. System conserves nuclear and fossil fuels, reducing powerplant capital and operating costs.
Near threshold fatigue crack propagation in pipeline steels in high pressure environments was studied. The objective was to determine the level of threshold stress intensity for fatigue crack growth rate behavior in a high strength low alloy X60 pipeline-type steel. Complete results have been generated for gaseous hydrogen at ambient pressure, laboratory air at ambient pressure and approximately 60% relative humidity as well as vacuum of 0.000067 Pa ( 0.0000005 torr) at R-ratios = K(min)/K(max) of 0.1, 0.5, and 0.8. Fatigue crack growth rate behavior in gaseous hydrogen, methane, and methane plus 10 percent hydrogen at 6.89 MPa (100 psi) was determined.
The potential for the reduction in propulsion system life cycle costs through the use of on-board water electrolysis to generate oxygen and hydrogen propellants, as well as the potential advantages of improved system safety and contamination impact, led to a study to evaluate candidate oxygen-/hydrogen-based propulsion systems. In this study a representative set of propulsion system requirements were compiled and candidate oxygen/hydrogen-based propulsion systems synthesized. These candidate concepts were screened and a systems evaluation was performed on the remaining eight candidate concepts. Detailed system schematics were prepared. Operational design conditions were determined and system weight, volume, energy requirements, and costs were calculated. Evaluation results indicated that the oxygen/hydrogen propulsion systems can provide simple, low cost, and viable systems for the IOC Space Station. Based on these data, a relative concept evaluation was conducted using as selection criteria reliability, safety, cost, technical risk, contamination, operational utility, growth potential, and integration potential. Top ranked candidate systems were recommended to NASA/MSFC for consideration for the IOC Space Station.
Preliminary results are reported from Doppler-shift measurements to the Voyager-2 spacecraft at a distance of 26 AU, obtained using the 32-m VLBI antenna at Medicina (Italy) during July and August 1988. The apparatus comprises the el-az antenna, an S-X-band receiver, a hydrogen maser to generate the reference signal, a Mark III VLBI terminal, and a digital tone extractor capable of isolating a tone of known frequency from a noisy signal and giving its phase and amplitude. A signal transmitted in S-band from the NASA Deep Space Network (DSN) station in Australia and retransmitted coherently in X-band by Voyager, was received 7 h 6 min later at Medicina and at the DSN station in Madrid. Sample data are presented graphically and shown to be of generally high quality; further in-depth analysis is under way.
The purification of reclaimed water is essential to water reclamation technology life-support systems in lunar/Mars habitats. An electrochemical UV reactor is being developed which generates oxidants, operates at low temperatures, and requires no chemical expendables. The reactor is the basis for an advanced oxidation process in which electrochemically generated ozone and hydrogen peroxide are used in combination with ultraviolet light irradiation to produce hydroxyl radicals. Results from this process are presented which demonstrate concept feasibility for removal of organic impurities and disinfection of water for potable and hygiene reuse. Power, size requirements, Faradaic efficiency, and process reaction kinetics are discussed. At the completion of this development effort the reactor system will be installed in JSC's regenerative water recovery test facility for evaluation to compare this technique with other candidate processes.
An investigation of a twin-engine fighter-type airplane model has been conducted in the Langley 16-foot transonic tunnel to determine the effect on drag of a fuselage volume addition incorporating streamline contouring and more extensive boattailing of the engine shrouds. The effect of hot exhausts from the turbojet engines was simulated with hydrogen peroxide gas generators using scaled nonafterburning engine nozzles. Afterbody pressure distributions, base drag coefficients, and forces on the fuselage-tail configurations are presented at Mach numbers from 0.80 to 1.05 angles of attack of 0 degree and 4 degrees for jet pressure ratios from 1 to 7. The effect of jet operation on both the basic and modified models was generally to decrease base pressures but to increase most other afterbody pressures and, therefore, to result in an overall decrease in fuselage-tail component drag. The addition of volume to the basic model reduced the base drag coefficient by 0.0010 with the jets off and 0.0018 at a typical cruise operating condition of a jet pressure ratio of 3, a Mach number of 0.85, and an angle of attack of 4 degrees. The overall jet-off reduction in fuselage-tail component drag due to the volume addition was a maximum of 0.0040 at a Mach number of 0.90 for an angle of attack of 4 degrees.
An investigation of the performance, stability, and control characteristics of a variable-sweep arrow-wing model with the outer wing panels swept 75 deg. has been conducted in the Langley 16-foot transonic tunnel. Four outboard engines located above and below the wing provided propulsive thrust, and, by deflecting in the pitch direction and rotating in the lateral plane, also produced control forces. The engine nacelles incorporated swept lateral and vertical fins for aerodynamic stability and control. Jet-off data were obtained with flow-through nacelles, simulating inlet flow; jet thrust and hot-jet interference effects were obtained with faired-nose nacelles housing hydrogen peroxide gas generators. Six-component force and moment data were obtained at Mach numbers from 0.60 to 1.05 through a range of angles of attack and angles of side-slip. Control characteristics were obtained by deflecting the nacelle-fin combinations as elevators, rudders, and ailerons at several fixed angles for each control. The results indicate that the basic wing-body configuration becomes neutrally stable or unstable at a lift coefficient of 0.15; addition of nacelles with fins delayed instability to a lift coefficient of 0.30. Addition of nacelles to the wing-body configuration increased minimum drag from 0.0058 to 0.0100 at a Mach number of 0.60 and from 0.0080 to 0.0190 at a Mach number of 1.05 with corresponding reductions in maximum lift-drag ratio of 12 percent and 33 percent, respectively. The nacelle-fin combinations were ineffective as longitudinal controls but were adequate as directional and lateral controls. The model with nacelles and fins was directionally and laterally stable; the stability generally increased with increasing lift. Jet interference effects on stability and control characteristics were small but the adverse effects on drag were greater than would be expected for isolated nacelles.
An investigation of the performance, stability, and control characteristics of a variable-sweep arrow-wing model (the "Swallow") with the outer wing panels swept 25 deg has been conducted in the Langley 16-foot transonic tunnel. The wing was uncambered and untwisted and had RAE 102 airfoil sections with a thickness-to-chord ratio of 0.14 normal to the leading edge. Four outboard engines located above and below the wing provided propulsive thrust, and, by deflecting in the pitch direction and rotating in the lateral plane, also produced control forces. A pair of swept lateral fins and a single vertical fin were mounted on each engine nacelle to provide aerodynamic stability and control. Jets-off data were obtained with flow-through nacelles, stimulating the effects of inlet flow; jet thrust and hot-jet interference effects were obtained with faired-nose nacelles housing hydrogen peroxide gas generators. Six-component force and moment data were obtained through a Mach number range of 0.40 to 0.90 at angles of attack and angles of sideslip from 0 deg to 15 deg. Longitudinal, directional, and lateral control were obtained by deflecting the nacelle-fin combinations as elevators, rudders, and ailerons at several fixed angles for each control.
We are currently developing an atomic oxygen diagnostic to study the degree of oxygen dissociation in ground-based facilities. The absorption of the (sub 3)P - (sup 3)S(sup 0) resonance triplet in the vacuum ultraviolet is a direct measure of the ground state number density of atomic oxygen. Although the integrated line strength is well known for these transitions, the line profile is not. We report the results of a series of experiments in which the line profile is measured in shock-heated oxygen. An ArF excimer laser and a hydrogen Raman shifter generate tunable VUV radiation at the resonance wavelength. The test gas is dissociated oxygen, generated in the Electric Arc Shock Tube (EAST) Facility at NASA-Ames Research Center. By measuring the absorption of known concentrations of atomic oxygen, we are able to study the absorption line profile. The results will serve as a calibration to apply this diagnostic in other flowfields.
In this work-in-progress report, we show the development of a unique high-pressure burner facility (up to 60 atm) that provides steady, reproducible premixed flames with high precision, while having the capability to use multiple fuel/oxidizer combinations. The highpressure facility has four optical access ports for applying different laser diagnostic techniques and will provide a standard reference flame for the development of a spectroscopic database in high-pressure/temperature conditions. Spontaneous Raman scattering (SRS) was the first diagnostic applied, and was used to successfully probe premixed hydrogen-air flames generated in the facility using a novel multi-jet micro-premixed array burner element. The SRS spectral data include contributions from H2, N2, O2, and H2O and were collected over a wide range of equivalence ratios ranging from 0.16 to 4.9 at an initial pressure of 10-atm via a spatially resolved point SRS measurement with a high-performance optical system. Temperatures in fuel-lean to stoichiometric conditions were determined from the ratio of the Stokes to anti-Stokes scattering of the Q-branch of N2, and those in fuel-rich conditions via the rotational temperature of H2. The SRS derived temperatures using both techniques were consistent and indicated that the flame temperature was approximately 500 K below that predicted by adiabatic equilibrium, indicating a large amount of heat-loss at the measurement zone. The integrated vibrational SRS signals show that SRS provides quantitative number density data in high-pressure H2-air flames.
Contents include the following: High power density motors. The training process of the organization development and training office. Modeling and analysis of a regenerative fuel cell propulsion system for a high altitude long endurance. Increasing the thermal stability of aluminum titanate for solid oxide mJEL cell anodes. Microstructural evaluation of forging parameters for superalloy disks. Epoxy adgesives for stator magnet assembly in stirling radioisotope generator. Nickel-Hydrogen and lithium ion space batteries. Statistical and prediction modeling of the Ka band using experimental results from ACTS propagation terminals at 20.185 and 27.505 GHz.
The Lunar Reconnaissance Orbiter's (LRO), Lunar Exploration Neutron Detector (LEND) was developed to refine the lunar surface hydrogen (H) measurements generated by the Lunar Prospector Neutron Spectrometer. LPNS measurements indicated a approx.4,6% decrease in polar epithermal fluxes equivalent to (1.5+/-0,8)% H concentration and are direct geochemical evidence indicating water /high H at the poles. Given the similar operational and instrumental objectives of the LEND and LPNS systems, an important science analysis step for LEND is to test correlation with existing research including LPNS measurements. In this analysis, we compare corrected low altitude epithermal rate data from LPNS available via NASA's Planetary Data System (PDS) with calibrated LEND epithermal maps using a cross-correlation technique