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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 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

Microgravity Disturbance Characterization of the Quench Module Insert (QMI) Phase Change Device (PCD)

The Materials Science Research Facility (MSRF) is a multi-user, multi-purpose facility for materials science research. One experiment within the MSRF will be the Quench Module Insert (QMI), a high-temperature furnace with unique capabilities for processing different classes of materials. The primary functions of the QMI furnace are to melt, directionally solidify, and quench metallic samples, providing data to aid in understanding the effects of the microgravity environment on the characteristics of these processed metals. The QMI houses sealed individual sample ampoules containing material to be processed. Quenching of the samples in the QMI furnace is accomplished by releasing low-melting-point metallic shoes into contact with the outside of the sample ampoule, dissipating heat and cooling the sample inside. The impact from this method of quench will induce sample vibrations which could be large enough to adversely affect sample quality. Utilizing breadboard hardware, the sample quench sequence, releasing the shoes, was conducted. Data was collected from accelerometers located on the breadboard sample cartridge, indicating the maximum acceleration achieved by the sample. The primary objective of the test described in this presentation was to determine the acceleration imparted on the sample by the shoe contact. From this information, the science community can better assess whether this method of quench will allow them to obtain the data they need.

Gattis, Christy↗
NASA NTRS2017

Drag-Free Performance of the ST7 Disturbance Reduction System Flight Experiment on the LISA Pathfinder

The Space Technology-7 Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft. LISA Pathfinder launched from Kourou, French Guiana on December 3, 2015. The DRS is tasked to validate two specific technologies: colloidal micro-Newton thrusters (CMNT) to provide low-noise control capability of the spacecraft, and drag-free control flight. This validation is performed using highly sensitive drag-free sensors, which are provided by the LISA Technology Package of the European Space Agency. The Disturbance Reduction System is required to maintain the spacecrafts position with respect to a free-floating test mass to better than 10nmHz, along its sensitive axis (axis in optical metrology). It also has a goal of limiting the residual accelerations of any of the two test masses to below 30 (1 + [f3 mHz]) fmsHz, over the frequency range of 1 to 30 mHz.This paper briefly describes the design and the expected on-orbit performance of the control system for the two modes wherein the drag-free performance requirements are verified. The on-orbit performance of these modes are then compared to the requirements, as well as to the expected performance, and discussed.

Attitude Control↗
NASA NTRS1975

Propellant reorientation with off-axis accelerations

Reorientation of propellant within a tank is important to the design of many acquisition and vent systems. A drop tower test program was conducted to determine the influence of off-axis accelerations on the motion of the liquid. A series of 39 tests was performed with a spherical tank and a cylindrical tank with hemispherical end domes, varying tank orientation, liquid volume and the magnitude of the acceleration. It was shown that reorientation under the effect of a pure axial acceleration, which has been studied in prior test programs, is a special case. The lateral component of the acceleration caused the liquid to reorient along one side of the tank. The motion of the liquid appeared to be independent of the magnitude of the lateral acceleration for the range of values considered.

Tegart, J.↗
NASA NTRS2001

Proceedings of the Twentieth International Microgravity Measurements Group Meeting

The International Microgravity Measurements Group annual meetings provide a forum for an exchange of information and ideas about various aspects of microgravity acceleration research in international microgravity research programs. These meetings are sponsored by the PI Microgravity Services (PIMS) project at the NASA Glenn Research Center. The twentieth MGMG meeting was held 7-9 August 2001 at the Hilton Garden Inn Hotel in Cleveland, Ohio. The 35 attendees represented NASA, other space agencies, universities, and commercial companies; eight of the attendees were international representatives from Canada, Germany, Italy, Japan, and Russia. Seventeen presentations were made on a variety of microgravity environment topics including the International Space Station (ISS), acceleration measurement and analysis results, science effects from microgravity accelerations, vibration isolation, free flyer satellites, ground testing, and microgravity outreach. Two working sessions were included in which a demonstration of ISS acceleration data processing and analyses were performed with audience participation. Contained within the minutes is the conference agenda which indicates each speaker, the title of their presentation, and the actual time of their presentation. The minutes also include the charts for each presentation which indicate the author's name(s) and affiliation. In some cases, a separate written report was submitted and has been included here.

DeLombard, Richard↗
NASA NTRS2001

Cardiopulmonary Responses to Supine Cycling during Short-Arm Centrifugation

The purpose of this study was to investigate cardiopulmonary responses to supine cycling with concomitant +G(sub z) acceleration using the NASA/Ames Human Powered Short-Arm Centrifuge (HPC). Subjects were eight consenting males (32+/-5 yrs, 178+/-5 cm, 86.1+/- 6.2 kg). All subjects completed two maximal exercise tests on the HPC (with and without acceleration) within a three-day period. A two tailed t-test with statistical significance set at p less than or equal to 0.05 was used to compare treatments. Peak acceleration was 3.4+/-0.1 G(sub z), (head to foot acceleration). Peak oxygen uptake (VO2(sub peak) was not different between treatment groups (3.1+/-0.1 Lmin(exp -1) vs. 3.2+/-0.1 Lmin(exp -1) for stationary and acceleration trials, respectively). Peak HR and pulmonary minute ventilation (V(sub E(sub BTPS))) were significantly elevated (p less than or equal to 0.05) for the acceleration trial (182+/-3 BPM (Beats per Minute); 132.0+/-9.0 Lmin(exp -1)) when compared to the stationary trial (175+/-3 BPM; 115.5+/-8.5 Lmin(exp -1)). Ventilatory threshold expressed as a percent of VO2(sub peak) was not different for acceleration and stationary trials (72+/-2% vs. 68+/-2% respectively). Results suggest that 3.4 G(sub z) acceleration does not alter VO2(sub peak) response to supine cycling. However, peak HR and V(sub E(sub BTPS)) response may be increased while ventilatory threshold response expressed as a function of percent VO2(sub peak) is relatively unaffected. Thus, traditional exercise prescription based on VO2 response would be appropriate for this mode of exercise. Prescriptions based on HR response may require modification.

Vener, J. M.↗
NASA NTRS1990

Prediction of force and acceleration control spectra for Space Shuttle orbiter sidewall-mounted payloads

The development of force and acceleration control spectra for vibration testing of Space Shuttle (STS) orbiter sidewall-mounted payloads requiresreliable estimates of the sidewall apparent weight and free (i.e. unloaded) vibration during lift-off. The feasibility of analytically predicting these quantities has been investigated through the development and analysis of a finite element model of the STS cargo bay. Analytical predictions of the sidewall apparent weight were compared with apparent weight measurements made on OV-101, and analytical predictions of the sidewall free vibration response during lift-off were compared with flight measurements obtained from STS-3 and STS-4. These analysis suggest that the cargo bay finite element model has potential application for the estimation of force and acceleration control spectra for STS sidewall-mounted payloads.

Hipol, Philip J.↗
NASA NTRS2011

Comparison of Test and Finite Element Analysis for Two Full-Scale Helicopter Crash Tests

Finite element analyses have been performed for two full-scale crash tests of an MD-500 helicopter. The first crash test was conducted to evaluate the performance of a composite deployable energy absorber under combined flight loads. In the second crash test, the energy absorber was removed to establish the baseline loads. The use of an energy absorbing device reduced the impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to analytical results. Details of the full-scale crash tests and development of the system-integrated finite element model are briefly described along with direct comparisons of acceleration magnitudes and durations for the first full-scale crash test. Because load levels were significantly different between tests, models developed for the purposes of predicting the overall system response with external energy absorbers were not adequate under more severe conditions seen in the second crash test. Relative error comparisons were inadequate to guide model calibration. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used for the second full-scale crash test. The calibrated parameter set reduced 2-norm prediction error by 51% but did not improve impact shape orthogonality.

Annett, Martin S.↗
NASA NTRS1981

Electric vehicle test report Cutler-Hammer Corvette

Vehicles were characterized for the state of the art assessment of electric vehicles. The vehicle evaluated was a Chevrolet Corvette converted to electric operation. The original internal combustion engine was replaced by an electric traction motor. Eighteen batteries supplied the electrical energy. A controller, an onboard battery charger, and several dashboard instruments completed the conversion. The emphasis was on the electrical portion of the drive train, although some analysis and discussion of the mechanical elements are included. Tests were conducted both on the road (actually a mile long runway) and in a chassis dynamometer equipped laboratory. The majority of the tests performed were according to SAE Procedure J227a and included maximum effort accelerations, constant speed range, and cyclic range. Some tests that are not a part of the SAE Procedure J227a are described and the analysis of the data from all tests is discussed.

Source record↗
NASA NTRS2016

ASTAR Flight Test: Overview and Spacing Results

The purpose of the NASA Langley Airborne Spacing for Terminal Arrival Routes (ASTAR) research aboard the Boeing ecoDemonstrator aircraft was to demonstrate the use of NASA's ASTAR algorithm using contemporary tools of the Federal Aviation Administration's Next Generation Air Transportation System (NEXTGEN). EcoDemonstrator is a Boeing test program which utilizes advanced experimental equipment to accelerate the science of aerospace and environmentally friendly technologies. The ASTAR Flight Test provided a proof-of-concept flight demonstration that exercised an algorithmic-based application in an actual aircraft. The test aircraft conducted Interval Management operations to provide time-based spacing off a target aircraft in non-simulator wind conditions. Work was conducted as a joint effort between NASA and Boeing to integrate ASTAR in a Boeing supplied B787 test aircraft while using a T-38 aircraft as the target. This demonstration was also used to identify operational risks to future flight trials for the NASA Air Traffic Management Technology Demonstration expected in 2017.

Roper, Roy D.↗
NASA NTRS2011

A Comparative Analysis of Two Full-Scale MD-500 Helicopter Crash Tests

Two full scale crash tests were conducted on a small MD-500 helicopter at NASA Langley Research Center fs Landing and Impact Research Facility. One of the objectives of this test series was to compare airframe impact response and occupant injury data between a test which outfitted the airframe with an external composite passive energy absorbing honeycomb and a test which had no energy absorbing features. In both tests, the nominal impact velocity conditions were 7.92 m/sec (26 ft/sec) vertical and 12.2 m/sec (40 ft/sec) horizontal, and the test article weighed approximately 1315 kg (2900 lbs). Airframe instrumentation included accelerometers and strain gages. Four Anthropomorphic Test Devices were also onboard; three of which were standard Hybrid II and III, while the fourth was a specialized torso. The test which contained the energy absorbing honeycomb showed vertical impact acceleration loads of approximately 15 g, low risk for occupant injury probability, and minimal airframe damage. These results were contrasted with the test conducted without the energy absorbing honeycomb. The test results showed airframe accelerations of approximately 40 g in the vertical direction, high risk for injury probability in the occupants, and substantial airframe damage.

Littell, Justin D.↗
NASA NTRS1980

Combustion in an acceleration field: A survey of Soviet literature

The effect of an acceleration field on the burning rate of a solid propellant was measured from -900g's to +1000g's using both double base and ammonium perchlorate based propellants. The acceleration fields were simulated using a centrifuge device and the burning rate was recorded. Both metalized and non-metalized variations of each propellant were tested and it was found that acceleration fields affect the burning rate. For the most part the theoretical predictions and the experimental results agreed.

Radloff, S. J.↗
NASA NTRS1972

Balanced-bellows spirometer

Compact balanced-bellows dry type spirometer was designed to be insensitive to acceleration fields along any or all coordinate axes. It provides true indication of respiratory action of test subject without need for calibration in acceleration fields.

Holden, G. G.↗
NASA NTRS2010

Suited Occupant Injury Potential During Dynamic Spacecraft Flight Phases

In support of the Constellation Space Suit Element [CSSE], a new space-suit architecture will be created for support of Launch, Entry, Abort, Microgravity Extra- Vehicular Activity [EVA], and post-landing crew operations, safety and, under emergency conditions, survival. The space suit is unique in comparison to previous launch, entry, and abort [LEA] suit architectures in that it utilizes rigid mobility elements in the scye (i.e., shoulder) and the upper arm regions. The suit architecture also utilizes rigid thigh disconnect elements to create a quick disconnect approximately located above the knee. This feature allows commonality of the lower portion of the suit (from the thigh disconnect down), making the lower legs common across two suit configurations. This suit must interface with the Orion vehicle seat subsystem, which includes seat components, lateral supports, and restraints. Due to the unique configuration of spacesuit mobility elements, combined with the need to provide occupant protection during dynamic vehicle events, risks have been identified with potential injury due to the suit characteristics described above. To address the risk concerns, a test series has been developed in coordination with the Injury Biomechanics Research Laboratory [IBRL] to evaluate the likelihood and consequences of these potential issues. Testing includes use of Anthropomorphic Test Devices [ATDs; vernacularly referred to as "crash test dummies"], Post Mortem Human Subjects [PMHS], and representative seat/suit hardware in combination with high linear acceleration events. The ensuing treatment focuses on test purpose and objectives; test hardware, facility, and setup; and preliminary results.

Dub, Mark O.↗
NASA NTRS2017

Drag-Free Performance of the ST7 Disturbance Reduction System Flight Experiment on the LISA Pathfinder

The Space Technology-7 Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft. LISA Pathfinder launched from Kourou, French Guiana on December 3, 2015. The DRS is tasked to validate two specific technologies: colloidal micro-Newton thrusters (CMNT) to provide low-noise control capability of the spacecraft, and drag-free controlflight. This validation is performed using highly sensitive drag-free sensors, which are provided by the LISA Technology Package of the European Space Agency. The Disturbance Reduction System is required to maintain the spacecrafts position with respect to a free-floating test mass to better than 10nm/(square root of Hz), along its sensitive axis (axis in optical metrology). It also has a goal of limiting the residual accelerations of any of the two test masses to below 30 x 10(exp -14) (1 + ([f/3 mHz](exp 2))) m/sq s/(square root of Hz), over the frequency range of 1 to 30 mHz.This paper briefly describes the design and the expected on-orbit performance of the control system for the two modes wherein the drag-free performance requirements are verified. The on-orbit performance of these modes are then compared to the requirements, as well as to the expected performance, and discussed.

Attitude Control↗
NASA NTRS1985

Flight testing the fixed-wing configuration of the Rotor Systems Research Aircraft (RSRA)

The Rotor Systems Research Aircraft (RSRA) is a unique research aircraft designed to flight test advanced helicopter rotor system. Its principal flight test configuration is as a compound helicopter. The fixed wing configuration of the RSRA was primarily considered an energy fly-home mode in the event it became necessary to sever an unstable rotor system in flight. While it had always been planned to flight test the fixed wing configuration, the selection of the RSRA as the flight test bed for the X-wing rotor accelerated this schedule. This paper discusses the build-up to, and the test of, the RSRA fixed wing configuration. It is written primarily from the test pilot's perspective.

Hall, G. W.↗
NASA NTRS1984

Flight testing the fixed wing configuration of the Rotor Systems Research Aircraft (RSRA)

The Rotor Systems Research Aircraft (RSRA) is a unique research aircraft designed to flight test advanced helicopter rotor system. Its principal flight test configuration is as a compound helicopter. The fixed wing configuration of the RSRA was primarily considered an energy fly-home mode in the event it became necessary to sever an unstable rotor system in flight. While it had always been planned to flight test the fixed wing configuraion, the selection of the RSRA as the flight test bed for the x-wing rotor accelerated this schedule. This paper discusses the build-up to, and the test of, the RSRA fixed wing configuration. It is written primarily from the test pilot's perspective.

Hall, G. W.↗
NASA NTRS1995

Energy measurement of electron beams by Compton scattering

A method has been proposed to utilize the well-known Compton scattering process as a tool to measure the centroid energy of a high energy electron beam at the 0.01% level. It is suggested to use the Compton scattering of an infrared laser off the electron beam, and then to measure the energy of the scattered gamma-rays very precisely using solid-state detectors. The technique proposed is applicable for electron beams with energies from 200 MeV to 16 GeV using presently available lasers. This technique was judged to be the most viable of all those proposed for beam energy measurements at the nearby Continuous Electron Beam Accelerator Facility (CEBAF). Plans for a prototype test of the technique are underway, where the main issues are the possible photon backgrounds associated with an electron accelerator and the electron and laser beam stabilities and diagnostics. The bulk of my ASEE summer research has been spent utilizing the expertise of the staff at the Aerospace Electronics Systems Division at LaRC to assist in the design of the test. Investigations were made regarding window and mirror transmission and radiation damage issues, remote movement of elements in ultra-high vacuum conditions, etc. The prototype test of the proposed laser backscattering method is planned for this December.

Keppel, Cynthia↗