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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Laser Incident in the NASA Unitary Plan Wind Tunnel

A viewgraph presentation describing the laser incident in the NASA Unitary Plan Wind Tunnel (UPWT) is shown. The topics include: 1) Unitary Plan Wind Tunnel (UPWT); 2) UPWT 11' x 11' Transonic Wind Tunnel; 3) UPWT 9' x 7' Supersonic Wind Tunnel; 4) 3D Particle Image Velocimetry (PIV); 5) PIV System in 11' x 11' Transonic Test Section; 6) PIV installation in 11' x 11' TWT; 7) 3% Space Shuttle Ascent Configuration Test in UPWT 9' x 7' Test Section; 8) PIV installation in 9' x 7' SWT; 9) PIV Laser System in 9' x 7' SWT; 10) PIV Laser System Access Window; 11) Cooling Water Leak at Rear of Power Supply; 12) PIV Laser Safety Interlock System; 13) Safety Interlock Cable; 14) Q-Switch located on top of 9' x 7' Test Section; 15) Investigation Findings and Recommendations; and 16) PIV Results for 3% Space Shuttle Model in UPWT 9' x 7'.

George, Michael W.↗
NASA NTRS1990

Cooling of rocket thrust chambers with liquid oxygen

Rocket engines using high pressure liquid oxygen (LOX) and kerosene (RP-1) as the propellants have been considered for future launch vehicle propulsion. Generally, in regeneratively cooled engines, the fuel is used to cool the combustion chamber. However, hydrocarbons such as RP-1 are limited in their cooling capability at high temperatures and pressures. Therefore, LOX is being considered as an alternative coolant. However, there has been concern as to the effect on the integrity of the chamber liner if oxygen leaks into the combustion zone through fatigue cracks that may develop between the cooling passages and the hot-gas side wall. To address this concern, an investigation was previously conducted with simulated fatigue cracks upstream of the thrust chamber throat. When these chambers were tested, an unexpected melting in the throat region developed which was not in line with the simulated fatigue cracks. The current experimental program was conducted in order to determine the cause for the failure in the earlier thrust chambers and to further investigate the effects of cracks in the thrust chamber liner upstream of the throat. The thrust chambers were tested at oxygen-to-fuel mixture ratios from 1.5 to 2.86 at a nominal chamber pressure of 8.6 MPa. As a result of the test series, the reason for the failure occurring in the earlier work was determined to be injector anomalies. The LOX leaking through the simulated fatigue cracks did not affect the integrity of the chambers.

Armstrong, Elizabeth S.↗
NASA NTRS1990

Cooling of rocket thrust chambers with liquid oxygen

Rocket engines using high pressure liquid oxygen (LOX) and kerosene (RP-1) as the propellants have been considered for future launch vehicle propulsion. Generaly, in regeneratively cooled engines, thefuel is used to cool the combustion chamber. However, hydrocarbons such as RP-1 are limited in their cooling capability at high temperatures and pressures. Therefore, LOX is being considered as an alternative coolant. However, there has been concern as to the effect on the integrity of the chamber liner if oxygen leaks into the combustion zone through fatigue cracks that may develop between the cooling passages and the hot-gas side wall. To address this concern, an investigation was previously conducted with simulated fatigue cracks upstream of the thrust chamber throat. When these chambers were tested, an unexpected melting in the throat region developed which was not in line with the simulated fatigue cracks. The current experimental program was conducted in order to determine the cause for the failure in the earlier thrust chambers and to further investigate the effects of cracks in the thrust chamber liner upstream of the throat. The thrust chambers were tested at oxygen-to-fuel mixture ratios from 1.5 to 2.86 at a nominal chamber pressure of 8.6 MPa. As a result of the test series, the reason for the failure occurring in the earlier work was determined to be injector anomalies. The LOX leaking through the simulated fatigue cracks did not affect the integrity of the chambers.

Armstrong, Elizabeth S.↗
DOE OSTI2026

Methane Mitigation Using Linear Motor Leak Recovery Compressor

GTI Energy (GTI), in collaboration with The University of Texas at Austin - Center for Electromechanics (UT‑CEM), designed, fabricated, and tested a linear motor–driven compressor intended to mitigate methane emissions at natural gas facilities across transmission, storage, gathering, and processing sectors of the gas value chain.

02 PETROLEUM↗
NASA NTRS1994

Microfabricated Hydrogen Sensor Technology for Aerospace and Commercial Applications

Leaks on the Space Shuttle while on the Launch Pad have generated interest in hydrogen leak monitoring technology. An effective leak monitoring system requires reliable hydrogen sensors, hardware, and software to monitor the sensors. The system should process the sensor outputs and provide real-time leak monitoring information to the operator. This paper discusses the progress in developing such a complete leak monitoring system. Advanced microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC) and Gencorp Aerojet (Aerojet). Changes in the hydrogen concentrations are detected using a PdAg on silicon Schottky diode structure. Sensor temperature control is achieved with a temperature sensor and heater fabricated onto the sensor chip. Results of the characterization of these sensors are presented. These sensors can detect low concentrations of hydrogen in inert environments with high sensitivity and quick response time. Aerojet is developing the hardware and software for a multipoint leak monitoring system designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Work has commenced on integrating the NASA LeRC-CWRU hydrogen sensors with the Aerojet designed monitoring system. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. Possible commercialization of the system will also be discussed.

Hunter, Gary W.↗
DOE OSTI2025

Fitness For Service Assessment of a Corroded Heat Exchanger

Within the Fermi National Accelerator complex, there exist various water systems that support accelerator operations. One of these systems is extremely vital to the operation of the machine; that is the cooling system. The cooling system consists of nine relatively large heat exchangers that take untreated pond water and use it to cool the process fluid that further cools machine components. Over the 30 years these heat exchangers have been in operation, they have undergone significant material loss on the channels. This material loss, due to various forms of corrosion such as galvanic and microbiologically influenced corrosion (MIC) and possibly others, has deteriorated more than 80% of the nominal wall thickness of some of the exchangers and placed them in a questionable state. ASME FFS-1 (API 579) has been applied to address the condition of the heat exchangers due to their noncompliance with the governing code, BPVC Sec. VIII Div. 1. The assessments encompassed ASME FFS-1 parts 4: General Metal Loss and 9: Crack Like Flaw using level 1, 2, and 3 analysis techniques based on inspection data obtained by API 510 inspections. Level 1 and 2 assessments were deemed unfit for the corroded regions due to their location relative to a major structural discontinuity (channel to tube-sheet joint), so a level 3 analysis was conducted according to ASME Sec. VIII Div. 2 (design by analysis) rules for pressure vessels. Supplemental information included pond water tests to determine an accurate future corrosion allowance due to lacking inspection history. A leak before break (LBB) route was chosen to evaluate the possibility of leaking prior to the onset of failure. The analysis of one heat exchanger shows that the possibility the channel will develop a pinhole leak over 2.5 more years of operation should not be overlooked, but burst was unlikely from operation. The use of fracture mechanics show, that if a through-wall crack were to develop, it would not propagate further than the channel geometry and cause a leak not greater than 35 GPM. Using ASME Section XI Code Case N-705-1, allowing us to operate with a leak until the next outage given certain operating conditions and developing a leak mitigation procedure, this heat exchanger is deemed fit-for-service.

Humenik, Alex [Fermilab]↗
NASA NTRS1975

The performance of components in the Skylab refrigeration system

The on-orbit performance of the Skylab refrigeration system components is presented. Flight anomalies are analyzed and performance of the newly developed components is described. Nine months of orbit data proved the practicality of the leak-free coolant system design. Flight proven application of a thermal capacitor and development test results of the first all-mechanical, low temperature mixing valve represent a significant advance in single-phase, low temperature coolant loop design. System flight data suggest that additional instrumentation and fluid filters could have prevented system orbit performance anomalies.

Daniher, C. E., Jr.↗
NASA NTRS1981

Safety testing of lithium cells

The testing consisted of a forced discharge to zero volts constant current under isothermal conditions. The temperature range was -40 to 65 C. Short circuit tests, drop tests, and puncture tests were run to determine how a cell might behave if it developed a leak. Once the sulfur dioxide is exhausted, a lithium acetontirile reaction occurs. An excess of sulfur dioxide must be maintained in order to avoid chemical explosions.

Bene, J.↗
NASA NTRS1982

Flightweight radiantly and actively cooled panel: Thermal and structural performance

A 2- by 4-ft flightweight panel was subjected to thermal/structural tests representative of design flight conditions for a Mach 6.7 transport and to off-design conditions simulating flight maneuvers and cooling system failures. The panel utilized Rene 41 heat shields backed by a thin layer of insulation to radiate away most of the 12 Btu/ft2-sec incident heating. A solution of ethylene glycol in water circulating through tubes in an aluminum-honeycomb-sandwich panel absorbed the remainder of the incident heating (0.8 Btu/sq ft-sec). The panel successfully withstood (1) 46.7 hr of radiant heating which included 53 thermal cycles and 5000 cycles of uniaxial inplane loading of + or - 1200 lfb/in; (2) simulated 2g-maneuver heating conditions and simulated cooling system failures without excessive temperatures on the structural panel; and (3) the extensive thermal/structural tests and the aerothermal tests reported in NASA TP-1595 without significant damage to the structural panel, coolant leaks, or hot-gas ingress to the structural panel.

Shore, C. P.↗
NASA NTRS1986

Test results for sawtooth-pattern damper seals - Leakage and rotordynamic coefficients

Test results consisting of direct and transverse force coefficients are presented for eleven sawtooth-pattern damper-seal configurations. The designation 'damper' seal refers to a seal which uses a deliberately roughened stator and smooth rotor to increase the net seal damping force. The designation 'sawtooth-pattern' refers to a stator-roughness pattern whose cross section normal to the axis of the seal resembles saw teeth with the teeth direction opposing fluid motion in the direction of shaft rotation. The sawtooth pattern yields axial grooves in the stator which are interrupted by spacer elements which act as flow constrictions or 'dams'. Sawtooth-pattern seals had more damping than smooth seals but less than the round-hole-pattern seals tested previously. If damping is sacrificed, sawtooth-pattern seals can be designed to leak less than round-hole-pattern seals.

Childs, D.↗
NASA NTRS2007

Stress Rupture Testing and Analysis of the NASA WSTF-JPL Carbon Overwrapped Pressure Vessels

Carbon composite overwrapped pressure vessels (COPVs) are widely used in applications from spacecraft to life support. COPV technology provides a pressurized media storage advantage over amorphous technology with weight savings on the order of 30 percent. The National Aeronautics and Space Administration (NASA) has been supporting the development of this technology since the early 1970's with an interest in safe application of these components to reduce mass to orbit. NASA White Sands Test Facility (WSTF) has been testing components in support of this objective since the 1980s and has been involved in test development and analysis to address affects of impact, propellant and cryogenic fluids exposure on Kevlar and carbon epoxy. The focus of this paper is to present results of a recent joint WSTF-Jet Propulsion Laboratories (JPL) effort to assess safe life of these components. The WSTF-JPL test articles consisted of an aluminum liner and a carbon fiber overwrap in an industry standard epoxy resin system. The vessels were specifically designed with one plus-minus helical wrap and one hoop wrap over the helical and they measured 4.23 x 11.4 in. long. 120 test articles were manufactured in August of 1998 of one lot fiber and resin and the 110 test articles were delivered to WSTF for test. Ten of the 120 test articles were burst tested at the manufacturer to establish the delivered fiber stress. Figure 1 shows a test article in a pre burst condition and with a hoop fiber failure (no leak of pressurized media) and post burst (failure of liner and loss of pressurized media).

Greene, Nathanael↗
NASA NTRS2014

Application of Model-based Prognostics to a Pneumatic Valves Testbed

Pneumatic-actuated valves play an important role in many applications, including cryogenic propellant loading for space operations. Model-based prognostics emphasizes the importance of a model that describes the nominal and faulty behavior of a system, and how faulty behavior progresses in time, causing the end of useful life of the system. We describe the construction of a testbed consisting of a pneumatic valve that allows the injection of faulty behavior and controllable fault progression. The valve opens discretely, and is controlled through a solenoid valve. Controllable leaks of pneumatic gas in the testbed are introduced through proportional valves, allowing the testing and validation of prognostics algorithms for pneumatic valves. A new valve prognostics approach is developed that estimates fault progression and predicts remaining life based only on valve timing measurements. Simulation experiments demonstrate and validate the approach.

prediction↗
NASA NTRS2014

Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)

NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the Initial valve design and subsequent improvements that resulted from prototype testing. The Initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the Titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated.Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the Initial Valve design was used to develop a second, more robust Aperture valve. Based on a check-ball design, the ETU flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, nonmagnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.

Mars↗
NASA NTRS2014

Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)

NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the Initial valve design and subsequent improvements that resulted from prototype testing. The Initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the Titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated. Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the Initial Valve design was used to develop a second, more robust Aperture valve. Based on a check-ball design, the ETU /flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, nonmagnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.

00000↗
NASA NTRS2014

Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)

NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the initial valve design and subsequent improvements that resulted from prototype testing. The initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated. Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the initial Valve design was used to develop a second, more robust Aperture Valve. Based on a check-ball design, the ETU / flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, non-magnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.

Engler, Charles↗
NASA NTRS2015

Design of the Brine Evaporation Bag for Increased Water Recovery in Microgravity

The existing water recovery system on the International Space Station (ISS) is limited to 75% reclamation; consequently, long duration space missions are currently unfeasible due to the large quantity of water necessary to sustain the crew. The Brine Evaporation Bag (BEB) is a proposed system to supplement the existing water recovery system aboard the ISS that can to increase water recovery to 99%. The largest barrier to high water recovery is mineral scaling inside the water recovery equipment, which leads to equipment failure; therefore, some water must remain to keep the minerals dissolved. This waste stream is liquid brine containing salts, acids, organics, and water. The BEB is designed to recover this remaining water while protecting the equipment from scale. The BEB consists of a sealed bag containing a hydrophobic membrane that allows water vapor and gas to pass through. It is operated under vacuum, heated, and continuously filled with brine to boil away the water. The water vapor is recovered and the solids are contained inside the bag for disposal. The BEB can dry the brine to a solid block. Ongoing work includes improving the design of the BEB and the evaporator to prevent leaks, maximize the rate of water removal, and minimize energy use and weight. Additional testing will determine whether designs are heat- or mass-transfer limited and the optimal water recovery rate.

Brine Evaporation Bag↗
NASA NTRSDate not supplied

Alternative MMOD Shielding Concepts

The main types of meteoroid and orbital debris (MMOD) shields are single-layer “monolithic” shields, dual-wall “Whipple” shields, and multi-wall shields (“Stuffed Whipple” and “multi-shock” are common types). Aluminum alloys are typically used for the outer bumper layer and for the rear wall of the dual- and multi-wall shields, although carbon-composites are increasingly employed in MMOD shields given their low-mass and high-strength. Ceramic (NextelTM) and KevlarTM fabrics are commonly used for the intermediate layers of Stuffed Whipple shields. The NASA Johnson Space Center (JSC) Hypervelocity Impact Technology (HVIT) group is continuously working to improve NASA spacecraft MMOD shielding by evaluating new materials and shielding concepts by test and analysis. HVIT has performed many hypervelocity impact tests over several years to evaluate alternative MMOD shield materials and concepts. This paper will provide results of this work in the following areas: (1) Material substitutions to improve radiation and MMOD protection within Stuffed Whipple shields, (2) Metallic and ceramic foam bumper and intermediate layer materials, (3) Self-sealing materials. In the first two areas listed above, the candidate shield materials were tested under similar test conditions and with fixed shield standoff and mass. Damage to the rear wall was quantified and compared to determine the best performing shield materials. In the self-sealing material evaluations, the test objective was to gauge the ability of different materials and techniques to stop leaks in a rear wall with a 1-atmosphere (air) delta-pressure across the wall. This paper provides results of the investigations and describes forward work to continue the development of the most promising MMOD shield alternatives. KevlarTM is a trademark of DuPont de Nemours, Inc. NextelTM is a trademark of 3M Corporation Note, Trade names and trademarks are used in this report for identification only. Their usage does not constitute an official endorsement, either expressed or implied, by the National Aeronautics and Space Administration.

Hypervelocity↗
NASA NTRSDate not supplied

Alternative MMOD Shielding Concepts

A core objective of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Hypervelocity Impact Technology (HVIT) group is to improve spacecraft meteoroid and orbital debris (MMOD) shielding by evaluating new materials and shielding concepts by test and analysis. This paper describes hypervelocity impact tests that were performed over several years to evaluate alternative MMOD shielding concepts. Specific objectives of the work were to incorporate improved MMOD and radiation protection within Stuffed Whipple shields, and to evaluate various self-sealing MMOD shielding concepts. The tests were performed under similar impact conditions and with fixed shield standoff and comparable overall shield mass. Damage to the rear wall was quantified and compared to determine the best performing shield concepts. Generally, the best shielding for both MMOD and radiation protection included polymer materials rich in hydrogen introduced into the intermediate and final layers of the shielding. In the self-sealing material evaluations, the test objective was to gauge the ability of different materials and techniques to stop leaks in a rear wall with a delta-pressure across the wall typical of spacecraft crew cabins (i.e., up to 1 atmosphere pressure). Shielding containing ionomer films and elastomer materials satisfied this objective for pressure shell holes up to 6mm diameter. This paper provides results of the investigations.

Orbital Debris↗