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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 253 records · Page 14

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NASA NTRS2010

Cascade Distillation Subsystem Development: Early Results from the Exploration Life Support Distillation Technology Comparison Test

In 2009, the Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, California) was assessed in the National Aeronautics and Space Administration (NASA) Exploration Life Support (ELS) distillation comparison test. The purpose of the test was to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. The CDS portion of the comparison test was conducted between May 6 and August 19, 2009. The system was challenged with two pretreated test solutions, each intended to represent a feasible wastewater generated in a surface habitat. The 30-day equivalent wastewater loading volume for a crew of four was intended to be processed for each wastewater solution. Test Solution 1 consisted of a mixed stream containing human-generated urine and humidity condensate. Test Solution 2 contained the addition of human-generated hygiene wastewater to the solution 1 waste stream components. Approximately 1500 kg of total wastewater was processed through the CDS during testing. Respective recoveries per solution were 93.4 +/- 0.7 and 90.3 +/- 0.5 percent. The average specific energy of the system during testing was calculated to be less than 120 W-hr/kg. The following paper provides detailed information and data on the performance of the CDS as challenged per the ELS distillation comparison test.

Callahan, Michael R.↗

NASA NTRS1990

The effect of swirl recovery vanes on the cruise noise of an advanced propeller

The SR-7A propeller was acoustically tested with and without downstream swirl recovery vanes to determine if any extra noise was caused by the interaction of the propeller wakes and vortices with these vanes. No additional noise was observed at the cruise condition over the angular range tested. The presence of the swirl recovery vanes did unload the propeller and some small peak noise reductions were observed from lower propeller loading noise. The propeller was also tested alone to investigate the behavior of the peak propeller noise with helical tip Mach number. As observed before on other propellers, the peak noise first rose with helical tip Mach number and then leveled off or decreased at higher helical tip Mach numbers. Detailed pressure-time histories indicate that a portion of the primary pressure pulse is progressively cancelled by a secondary pulse as the helical tip Mach number is increased. This cancellation appears to be responsible for the peak noise behavior at high helical tip Mach numbers.

Dittmar, James H.↗

NASA NTRS1990

The effect of swirl recovery vanes on the cruise noise of an advanced propeller

Dittmar, James H.↗

NASA NTRS1942

Free-Spinning-Tunnel Tests of a 1/23.75-Scale Model of the Douglas DC-3 Airplane

Explore the source record for details and available documents.

SPINNING - RECOVERY↗

NASA NTRS2016

Construction of Supersonic Flight Dynamics Test (SFDT-2) Vehicle Monte Carlo Splashdown Footprints for Use in Range Safety and Recovery Planning

Overview of Low Density Supersonic Decelerator (LDSD) SFDT-2 ( Supersonic Flight Dynamics Test-2) flight profile; Description of Monte Carlo flight dynamics simulations performed; Modeling and uncertainties; Results with statistical prediction of test vehicle splashdown location; Use of Monte Carlo results for range safety and recovery planning.

Strauss, Bill↗

DOE OSTI2025

Electro-Thermo-Mechanical (ETM) Study on Submarine Dynamic Power Cables (SDPC) for Offshore Wind Transmission

Understanding the failure mechanisms of submarine dynamic power cables (SDPC) is critical for innovative design to meet the 2035 cost reduction target of U.S. DOE Floating Offshore Wind Shot. This is important because the current design suffers a significant failure rate in the field. This project conducted a systematic electro-thermo-mechanical (ETM) experimental study on the power cores extracted from a 15kV power cable with three cores of copper conductor, ethylene propylene rubber (EPR) insulation, and continuously corrugated welded aluminum armor (CCWA). An ETM testing system was developed by integrating a high voltage (HV) amplifier, two ceramic heaters, and a rod-plate transverse compression setup into a mechanical testing machine. Increasing temperature from room temperature (RT, 22 degree C) to 90 degree C resulted in the 67% decrease in the failure mechanical load as defined by the dielectric breakdown. Under creep mechanical loading, the dielectric breakdown time was decreased by 70% for a given mechanical load when the specimen temperature increased from RT to 90oC. The failure strain in both monotonic and creep mechanical loading modes was related to the maximum mechanical load applied. Although the dielectric breakdown occurred in the ETM test, the post-test measurement revealed an impressive recovery of electric resistance. The failure analysis on cross section of tested specimens indicated a sizable gap across insulation layer near the area between copper conductor and loading rod, which apparently resulted from online dielectric failure and offline elastic recovery of components including conductor and insulation layer.

17 WIND ENERGY↗

DOE OSTI2024

Production of Germanium and Gallium Concentrates for Industrial Processes

A conceptual design of a process to produce germanium and gallium metal from mixed rare earth concentrates (consisting of oxides or carbonates) (MREC) produced from lignite carbon-ore was developed. The design was based on past work associated with the recovery of Ge from carbon-ore ash, modeling of the behavior of Ge and Ga in pyrometallurgical processes, and laboratory testing of the potential recovery of Ge and Ga from MREC. A teaming plan was developed that encompasses the entire supply chain that consisted of the Ge and Ga-rich carbon-ore resource, MREC pilot scale concentrate producer, MREC processing facility to produce Ge/Ga concentrates, refining of Ge and Ga concentrates to produce high purity metals (99.999+ purity), and Ge/Ga end users. A research plan was developed to transition the Ge and Ga separation from MREC, concentrating, and refining technology from a conceptual design to commercial scale. A technical and economic assessment of the conceptual design indicated that MREC derived from the UND process can produce 90 to 99% pure Ge and Ga concentrates at >20% lower costs.

01 COAL, LIGNITE, AND PEAT↗

NASA NTRS1942

Investigation of Diving Moments of a Pursuit Airplane in the Ames 16-Foot High Speed Wind Tunnel

A pursuit type airplane encountered severe diving moments in high-speed dives which make recovery difficult. For the purpose of investigating these diving moments and finding means for their reduction, a 1/6-scale model of the airplane was tested in the 16-foot high-speed wind tunnel at Ames Aeronautical Laboratory. The test results indicate that up to a Mach number of at least 0.75, the limit of the tests, the dive-recovery difficulties can be alleviated and the longitudinal maneuverability improved by the substitution of a long symmetrical fuselage for the standard fuselage.

MACH NUMBER↗

NASA NTRS2009

Cascade Distillation Subsystem Development: Early Results From the Exploration Life Support Distillation Technology Comparison Test

In 2009, the Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, CA) was assessed in the National Aeronautics and Space Administration (NASA) Exploration Life Support (ELS) distillation comparison test. The purpose of the test was to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. The CDS portion of the comparison test was conducted between May 6 and August 19, 2009. The system was challenged with two pretreated test solutions, each intended to represent a feasible wastewater generated in a surface habitat. The 30-day equivalent wastewater loading volume for a crew of four was processed for each wastewater solution. Test Solution 1 consisted of a mixed stream containing human-generated urine and humidity condensate. Test Solution 2 contained the addition of human-generated hygiene wastewater to the solution 1 waste stream components. Approximately 1500 kg of total wastewater was processed through the CDS during testing. Respective recoveries per solution were 93.4 +/- 0.7 and 90.3 +/- 0.5%. The average specific energy of the system was calculated to be less than 130 W-hr/kg. The following paper provides detailed information and data on the performance of the CDS as challenged per the ELS distillation comparison test.

Callahan, Michael R.↗

DOE OSTI2022

An acid baking approach to enhance heavy rare earth recovery from bituminous coal-based sources

The recovery of rare earth elements (REEs) from secondary resources, particularly coal-based materials, has recently received attention due to supply and demand imbalance. Research reported to date indicates that a high REE recovery can be realized when treating bituminous coal sources using strong acid solutions of approximately100 g/L or higher. This study introduces an approach to enhance the total rare earth recovery (TREE), especially for heavy rare earth elements (HREEs), from these coal sources at significantly lower acid concentrations. Based on the presence of REE minerals like monazite and xenotime, a detailed investigation was undertaken to quantify three pre-leach treatment methods, i.e., 1) roasting, 2) direct acid baking, and 3) acid baking after roasting. Roasting tests at 600°C revealed that the recovery of light REEs (LREEs) was enhanced while the recovery of HREEs remained relatively unaffected. LREE and HREE recovery values of 38.3% and 21.3%, respectively, were achieved using a 50 g/L (0.5 M) sulfuric acid solution at 5% solid concentration and a solution temperature of 75°C for 2 h. Comparatively, direct acid baking at 250°C provided substantial increases in LREE and HREE recovery values to approximately 49.4% and 53.0%, respectively, using an equivalent acid dosage. Recoveries were maximized to 77.0% and 79.6% for LREE and HREE, respectively, by roasting followed by acid baking. Similar results were obtained from the treatment of a second bituminous coal source. Due to strong correlations between REE and Al recovery values, tests were performed on kaolinite and illite, which were prominent clay minerals within the source coals. In conclusion, these experiments revealed that the REE recovery improvements were likely a result of dehydroxylation of clays and subsequent release and decomposition of REE-bearing minerals such as monazite, xenotime and zircon.

42 ENGINEERING↗

NASA NTRS1991

Investigations of detail design issues for the high speed acoustic wind tunnel using a 60th scale model tunnel. Part 1: Tests with open circuits

This report summarizes the tests on the 1:60 scale model of the High Speed Acoustic Wind Tunnel (HSAWT) performed during the period of November 1989 to December 1990. Throughout the testing the tunnel was operated in the 'open circuit mode', that is when the airflow was induced by a powerful exhaust fan located outside the tunnel circuit. The tests were first performed with the closed test section and were subsequently repeated with the open test section. While operating with the open test section, a novel device, called the 'nozzle-diffuser,' was also tested in order to establish its usefulness of increasing pressure recovery in the first diffuser. The tests established the viability of the tunnel design. The flow distribution in each tunnel component was found acceptable and pressure recovery in the diffusers were found satisfactory. The diffusers appeared to operate without flow separation. All tests were performed at NASA LaRC.

Barna, P. Stephen↗

NASA NTRS1991

An autonomous fault detection, isolation, and recovery system for a 20-kHz electric power distribution test bed

Future space explorations will require long term human presence in space. Space environments that provide working and living quarters for manned missions are becoming increasingly larger and more sophisticated. Monitor and control of the space environment subsystems by expert system software, which emulate human reasoning processes, could maintain the health of the subsystems and help reduce the human workload. The autonomous power expert (APEX) system was developed to emulate a human expert's reasoning processes used to diagnose fault conditions in the domain of space power distribution. APEX is a fault detection, isolation, and recovery (FDIR) system, capable of autonomous monitoring and control of the power distribution system. APEX consists of a knowledge base, a data base, an inference engine, and various support and interface software. APEX provides the user with an easy-to-use interactive interface. When a fault is detected, APEX will inform the user of the detection. The user can direct APEX to isolate the probable cause of the fault. Once a fault has been isolated, the user can ask APEX to justify its fault isolation and to recommend actions to correct the fault. APEX implementation and capabilities are discussed.

Quinn, Todd M.↗

NASA NTRS1993

The development and flight test of a deployable precision landing system for spacecraft recovery

A joint NASA Dryden Flight Research Facility and Johnson Space Center program was conducted to determine the feasibility of the autonomous recovery of a spacecraft using a ram-air parafoil system for the final stages of entry from space that included a precision landing. The feasibility of this system was studied using a flight model of a spacecraft in the generic shape of a flattened biconic which weighed approximately 150 lb and was flown under a commercially available, ram-air parachute. Key elements of the vehicle included the Global Positioning System guidance for navigation, flight control computer, ultrasonic sensing for terminal altitude, electronic compass, and onboard data recording. A flight test program was used to develop and refine the vehicle. This vehicle completed an autonomous flight from an altitude of 10,000 ft and a lateral offset of 1.7 miles which resulted in a precision flare and landing into the wind at a predetermined location. At times, the autonomous flight was conducted in the presence of winds approximately equal to vehicle airspeed. Several techniques for computing the winds postflight were evaluated. Future program objectives are also presented.

Sim, Alex G.↗

NASA NTRS1947

Investigations of Tumbling Characteristics of a 1/20-Scale Model of the Northrop N-9M Airplane

The tumbling characteristics of a 1/20-scale model of the Northrop N-9M airplane have been determined in the Langley 20-foot free-spinning tunnel for various configurations and loading conditions of the model. The investigation included tests to determine whether recovery from a tumble could be effected by the use of parachutes. An estimation of the forces due to acceleration acting on the pilot during a tumble was made. The tests were performed at an equivalent test altitude of 15,000 feet. The results of the model tests indicate that if the airplane is stalled with its nose up and near the vertical, or if an appreciable amount of pitching rotation is imparted to the airplane as through the action of a strong gust, the airplane will either tumble or oscillate in pitch through a range of angles of the order of +/-120 deg. The normal flying controls will probably be ineffective in preventing or in terminating the tumbling motion. The results of the model tests indicate that deflection of the landing flaps full down immediately upon the initiation of pitching rotation will tend to prevent the development of a state of tumbling equilibrium. The simultaneous opening of two-7-foot diameter parachutes having drag coefficients of 0.7, one parachute attached to the rear portion of each wing tip with a towline between 10 and 30 feet long, will provide recovery from a tumble. The accelerations acting on the pilot during a tumble will be dangerous.

MacDougall, George F., Jr.↗

DOE OSTI2025

Does class matter? Understanding differential pandemic recovery via a building typology

This study investigates the recovery of building-level footfall from the COVID-19 pandemic using privacy-preserving mobile devices-based footfall data within 60 downtown areas in the USA and Canada. Using clustering, we identify five distinct building typologies based on their characteristics, including rent, quality and recovery rates. The results reveal significant variation of recovery rates by building features. We find negative relationships with footfall recovery for both the percentage of office and remote work tenants and building quality. In contrast, buildings with traditional work tenants and retail functions achieve higher recovery rates. We also test the ‘flight to quality’ hypothesis via on our typology results. High-quality office buildings (Class A+) continue to have high rents but experience low physical footfall recovery, which suggests that this class is not as resilient as portrayed. The findings thus suggest the importance of considering both economic and footfall resilience in evaluating the performance of office buildings.

Covid-19↗

NASA NTRSDate not supplied

Tracking and Recovery of the LOFTID RV (Low-Earth Orbit Flight Test of an Inflatable Decelerator Reentry Vehicle)

The LOFTID mission launched from Vandenberg on Nov 10, 2022, and successfully demonstrated the reentry of a 6m diameter inflatable aeroshell from low Earth orbit. This paper will cover the design features implemented to enable recovery of the flight vehicle, and will discuss the splashdown calculations, in-flight tracking, recovery from the ocean, and post-flight inspection of the flight vehicle. To support recovery of the RV and ejected data recorder after splashdown, a recovery ship was pre-positioned near the predicted splashdown ellipse in the Pacific Ocean. The splashdown ellipse was repeatedly updated as launch approached. In-flight tracking included transmission from the RV of GPS data through both the Iridium satellite network and the LoRa direct RF link, along with IR video cameras on the recovery ship and airborne imagery from the SCIFLI Team. Using both the GPS data and the IR imagery, the recovery ship tracked down the RV, and deployed an inflatable boat to approach the RV and attach it to the ship’s crane, after which the RV was hoisted on board and secured in its GSE recovery stand. The ship then tracked down the ejected data recorder, which was also broadcasting its GPS data, and pulled it from the water. Once the ship returned to port, the RV was hoisted ashore for additional inspection, removal of the data recorders, and repackaging for shipment back to NASA Langley.

Robert A Dillman↗

NASA NTRS2001

Compressor Stall Recovery Through Tip Injection Assessed

Aerodynamic stability is a fundamental limit in the compressor design process. The development of robust techniques for increasing stability has several benefits: enabling higher loading and fewer blades, increasing safety throughout a mission, increasing tolerance to stage mismatch during part-speed operation and speed transients, and providing an opportunity to match stages at the compressor maximum efficiency point, thus reducing fuel burn. Mass injection upstream of the tip of a high-speed axial compressor rotor is a stability enhancement approach known to be effective in suppressing stall in tip-critical rotors if the injection is activated before stall occurs. This approach to stall suppression requires that a reliable stall warning system be available. Tests have recently been performed to assess whether steady injection can also be used to recover from fully developed stall. If mass injection is effective in recovering from stall quickly enough to avoid structural damage or loss of engine power, then a stall warning system may not be required. The stall recovery tests were performed on a transonic compressor rotor at its design tip speed of 1475 ft/sec using four injectors evenly spaced around the compressor case upstream of the rotor. The injectors were connected to an external air source. In an actual engine application, the injected air would be supplied with compressor bleed air. The injectors were isolated from the air source by a fast-acting butterfly valve. With the injectors turned off, the compressor was throttled into stall. Air injection was then activated with no change in throttle setting by opening the butterfly valve. The compressor recovered from stall at a fixed throttle setting with the aid of tip injection. The unsteady operating characteristic of the rotor was measured during these tests using high-response pressure sensors located upstream and downstream of the rotor. The figure shows the results, where the unsteady pressure and mass flow are superimposed on the steady operating characteristic. The total injected mass flow was equal to 1.3 percent of the compressor flow. The solid line with no solid squares on it denotes the operating point during the beginning of throttle closure and the initial drop into stall. The gray traces denote the operating point during an additional throttle closure that occurred over the next 1200 rotor revolutions (4 sec). The dashed line denotes the recovery from stall that occurred during 90 rotor revolutions (0.3 sec) after the injectors were activated with no change in throttle setting. Tip injection not only recovers the compressor from stall, but also restores the compressor to its pre-stall level of pressure rise. In contrast, standard stall recovery schemes such as compressor bleed, stator vane actuation, or engine throttle modulation result in a loss of pressure rise across the compressor, which results in a loss of engine power.

Suder, Ken L.↗

DOE OSTI2025

Effect of Transverse Compression on the Dielectric Breakdown of Power Cable with Ethylene Propylene Rubber Insulation

Understanding of the failure mechanisms of submarine dynamic power cables (SDPC) is critical for innovative design to meet the 2035 cost reduction target of U.S. DOE Floating Offshore Wind Shot. This is important because the current design suffers a significant failure rate in the field. This project explored a multiphysics approach and conducted systematic electro-thermo-mechanical (ETM) experimental study on the power cores extracted from a 15 kV power cable. The power cable had three cores of copper conductor and ethylene propylene rubber (EPR) insulation. An ETM testing system with transverse compression capability was developed. Mechanical loading induced dielectric breakdown. Increasing temperature from room temperature (RT, 22 degrees Celsius) to 90 degrees Celsius resulted in the 67% decrease in the failure mechanical load as defined by the dielectric breakdown. With the same temperature rise, the creep mechanical load was reduced by 70% at a given dielectric breakdown time. The post-test measurement revealed an impressive recovery of electrical resistance, although the dielectric breakdown occurred in the ETM test that would not be captured without the use of ETM testing.

Wang, Hong [ORNL] (ORCID:0000000201730545)↗