SEARCH · Engineering Papers
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.
Survey topics include - heat transfer boundaries of near critical region, free, natural, and forced convection experiments, oscillations, geometric effects, parameters which appear to be significant to heat transfer in critical region, and theories which have been proposed for region.
As the number of scientific experiments for the surface of Mars grows, the need for effective surface transportation becomes critical. Because of the diversity of the experiments proposed, as well as the desire to explore Mars from the equator to the poles, the optimum surface vehicle configuration is not obvious. Five candidate vehicles are described, with an estimate of their size and performance. In order to maximize the success of a manned Mars mission, it appears that two vehicles should be designed for surface transportation: an advanced long-range rover, and a remotely-piloted airplane.
A cavity heat pipe experiment has been designed to test the critical issues involved with incorporating thermal energy storage canisters into a heat pipe. The experiment is a replication of the operation of a heat receiver for a Brayton solar dynamic power cycle. The heat receiver is composed of a cylindrical receptor surface and an annular heat pipe with thermal energy storage canisters and gaseous working fluid heat exchanger tubes surrounding it. Hardware for the cavity heat pipe experiment will consist of a sector of the heat pipe, complete with gas tube and thermal energy storage canisters. Thermal cycling tests will be performed on the heat pipe sector to simulate the normal energy charge/discharge cycle of the receiver in a spacecraft application.
Beginning with OSTA-1 in November 1981, and ending with Neurolab in March 1998, thirty-six shuttle missions are considered Spacelab missions because they carried various Spacelab components such as the Spacelab module, the pallet, the Instrument Pointing System (IPS), or the MPESS. The experiments carried out during these flights included astrophysics, solar physics, plasma physics, atmospheric science, Earth observations, and a wide range of microgravity experiments in life sciences, biotechnology, materials science, and fluid physics which includes combustion and critical point phenomena. In all, some 764 experiments were conducted by investigators from the United States, Europe, and Japan. These experiments resulted in several thousand papers published In refereed journals, and thousands more in conference proceedings, chapters in books, and other publications. The purpose of this Spacelab Science Results Study is to document the contributions made in each of the major research areas by giving a brief synopsis of the more significant experiments and an extensive list of the publications that were produced. We have also endeavored to show how these results impacted the existing body of knowledge, where they have spawned new fields, and, if appropriate, where the knowledge they produced has been applied.
Beginning with OSTA-1 in November 1981, and ending with Neurolab in March 1998, thirty-six shuttle missions are considered Spacelab missions because they carried various Spacelab components such as the Spacelab module, the pallet, the Instrument Pointing System (IPS), or the MPESS. The experiments carried out during these flights included astrophysics, solar physics, plasma physics, atmospheric science, Earth observations, and a wide range of microgravity experiments in life sciences, biotechnology, materials science, and fluid physics which includes combustion and critical point phenomena. In all, some 764 experiments were conducted by investigators from the United States, Europe, and Japan. These experiments resulted in several thousand papers published in refereed journals, and thousands more in conference proceedings, chapters in books, and other publications. The purpose of this Spacelab Science Results Study is to document the contributions made in each of the major research areas by giving a brief synopsis of the more significant experiments and an extensive list of the publications that were produced. We have also endeavored to show how these results impacted the existing body of knowledge, where they have spawned new fields, and, if appropriate, where the knowledge they produced has been applied.
Beginning with OSTA-1 in November 1981, and ending with Neurolab n March 1998, thirty-six shuttle missions are considered Spacelab missions because they carried various Spacelab components such as the Spacelab module, the pallet, the Instrument Pointing System (IPS), or the MPESS (Mission Peculiar Experiment Support Structure). The experiments carried out during these flights included astrophysics, solar physics, plasma physics, atmospheric science, Earth observations, and a wide range of microgravity experiments in life sciences, biotechnology, materials science, and fluid physics which includes combustion and critical point phenomena. In all, some 764 experiments were conducted by investigators from the United States, Europe, and Japan. These experiments resulted in several thousand papers published in refereed journals, and thousands more in conference proceedings, chapters in books, and other publications. The purpose of this Spacelab Science Results Study is to document the contributions made in each of the major research areas by giving a brief synopsis of the more significant experiments and an extensive list of the publications that were produced. We have also endeavored to show how these results impacted the existing body of knowledge, where they have spawned new fields, and, if appropriate, where the knowledge they produced has been applied.
As shown in space flight experiments, g-jitter is a critical issue affecting solidification processing of materials in microgravity. This study aims to provide, through extensive numerical simulations and ground based experiments, an assessment of the use of magnetic fields in combination with microgravity to reduce the g-jitter induced convective flows in space processing systems. Analytical solutions and 2-D and 3-D numerical models for g-jitter driven flows in simple solidification systems with and without the presence of an applied magnetic field have been developed and extensive analyses were carried out. A physical model was also constructed and PIV measurements compared reasonably well with predictions from numerical models. Some key points may be summarized as follows: (1) the amplitude of the oscillating velocity decreases at a rate inversely proportional to the g-jitter frequency and with an increase in the applied magnetic field; (2) the induced flow oscillates at approximately the same frequency as the affecting g-jitter, but out of a phase angle; (3) the phase angle is a complicated function of geometry, applied magnetic field, temperature gradient and frequency; (4) g-jitter driven flows exhibit a complex fluid flow pattern evolving in time; (5) the damping effect is more effective for low frequency flows; and (6) the applied magnetic field helps to reduce the variation of solutal distribution along the solid-liquid interface. Work in progress includes developing numerical models for solidification phenomena with the presence of both g-jitter and magnetic fields and developing a ground-based physical model to verify numerical predictions.
Beginning with OSTA-1 in November 1981 and ending with Neurolab in March 1998, a total of 36 Shuttle missions carried various Spacelab components such as the Spacelab module, pallet, instrument pointing system, or mission peculiar experiment support structure. The experiments carried out during these flights included astrophysics, solar physics, plasma physics, atmospheric science, Earth observations, and a wide range of microgravity experiments in life sciences, biotechnology, materials science, and fluid physics which includes combustion and critical point phenomena. In all, some 764 experiments were conducted by investigators from the U.S., Europe, and Japan. The purpose of this Spacelab Science Results Study is to document the contributions made in each of the major research areas by giving a brief synopsis of the more significant experiments and an extensive list of the publications that were produced. We have also endeavored to show how these results impacted the existing body of knowledge, where they have spawned new fields, and if appropriate, where the knowledge they produced has been applied.
The role of experiment in the development of Computation Fluid Dynamics (CFD) for aerodynamic flow prediction is discussed. The CFD verification is a concept that depends on closely coordinated planning between computational and experimental disciplines. Because code applications are becoming more complex and their potential for design more feasible, it no longer suffices to use experimental data from surface or integral measurements alone to provide the required verification. Flow physics and modeling, flow field, and boundary condition measurements are emerging as critical data. Four types of experiments are introduced and examples given that meet the challenge of validation: flow physics experiments; flow modeling experiments; calibration experiments; and verification experiments. Measurement and accuracy requirements for each of these differ and are discussed. A comprehensive program of validation is described, some examples given, and it is concluded that the future prospects are encouraging.
The role of experiment in the development of Computational Fluid Dynamics (CFD) for aerodynamic flow prediction is discussed. The CFD verification is a concept that depends on closely coordinated planning between computational and experimental disciplines. Because code applications are becoming more complex and their potential for design more feasible, it no longer suffices to use experimental data from surface or integral measurements alone to provide the required verification. Flow physics and modeling, flow field, and boundary condition measurements are emerging as critical data. Four types of experiments are introduced and examples are given that meet the challenge of validation: flow physics experiments; flow modeling experiments; calibration experiments; and verification experiments. Measurement and accuracy requirements for each of these differ and are discussed. A comprehensive program of validation is described, some examples given, and it is concluded that the future prospects are encouraging.
Embedded domain-specific languages (EDSLs) are an approach for quickly building new languages while maintaining the advantages of a rich metalanguage. We argue in this experience report that the "EDSL approach" can surprisingly ease the task of building a high-assurance compiler.We do not strive to build a fully formally-verified tool-chain, but take a "do-it-yourself" approach to increase our confidence in compiler-correctness without too much effort. Copilot is an EDSL developed by Galois, Inc. and the National Institute of Aerospace under contract to NASA for the purpose of runtime monitoring of flight-critical avionics. We report our experience in using type-checking, QuickCheck, and model-checking "off-the-shelf" to quickly increase confidence in our EDSL tool-chain.
Due to its better superconducting properties (critical temperature Tc~ 18.3 K, superheating field Hsh~ 400 mT), Nb₃Sn is considered as a potential alternative to niobium (Tc~ 9.25 K, Hsh~ 200 mT) for superconducting radiofrequency (SRF) cavities for particle acceleration. Magnetron sputtering is an effective method to produce superconducting Nb₃Sn films. We deposited superconducting Nb₃Sn films on samples with magnetron sputtering using co-sputtering, sequential sputtering, and sputtering from a stoichiometric target. Nb₃Sn films produced by magnetron sputtering in our previous experiments have achieved DC superconducting critical temperature up to 17.93 K and RF superconducting transition at 17.2 K. A magnetron sputtering system with two identical cylindrical cathodes that can be used to sputter Nb₃Sn films on cavities has been designed and is under development now. We report on the design and the current progress on the development of the system.
Combustion of methanol, ethanol, propanol -1, n - pentane, n - heptane and n - decane was observed in air under natural convection conditions at pressures up to 100 atm. The droplets were simulated by porous spheres with diameters in the range 0.63 - 1.90 cm. The pressure levels of the tests were high enough so that near critical combustion was observed for methanol and ethanol. Measurements were made of the burning rate and liquid surface temperatures of the fuels. The data were compared with variable property analysis of the combustion process, including a correction for natural convection. The burning rate predictions of the various theories were similar and in fair agreement with the data. The high pressure theory gave the best prediction for the liquid surface temperatures of ethanol and propanol -1 at high pressure. The experiments indicated the approach of critical burning conditions for methanol and ethanol at pressures on the order of 80 - 100 atm, which was in good agreement with the predictions of both the low and high pressure analysis.
The NASA Goddard Space Flight Center (GSFC) Global Positioning System (GPS) applications test facility has been established within the GSFC Guidance Navigation and Control Center. The GPS test facility is currently housing the Global Simulation Systems Inc. (GSSI) STR2760 GPS satellite 40-channel attitude simulator and a STR4760 12-channel navigation simulator. The facility also contains a few other resources such as an atomic time standard test bed, a rooftop antenna platform and a radome. It provides a new capability for high dynamics GPS simulations of space flight that is unique within the aerospace community. The GPS facility provides a critical element for the development and testing of GPS based technologies i.e. position, attitude and precise time determination used on-board a spacecraft, suborbital rocket balloon. The GPS simulation system is configured in a transportable rack and is available for GPS component development as well as for component, spacecraft subsystem and system level testing at spacecraft integration and tests sites. The GPS facility has been operational since early 1996 and has utilized by space flight projects carrying GPS experiments, such as the OrbView-2 and the Argentine SAC-A spacecrafts. The SAC-A pre-flight test data obtained by using the STR2760 simulator and the comparison with preliminary analysis of the GPS data from SAC-A telemetry are summarized. This paper describes pre-flight tests and simulations used to support a unique spaceborne GPS experiment. The GPS experiment mission objectives and the test program are described, as well as the GPS test facility configuration needed to verify experiment feasibility. Some operational and critical issues inherent in GPS receiver pre-flight tests and simulations using this GPS simulation, and test methodology are described. Simulation and flight data are presented. A complete program of pre-flight testing of spaceborne GPS receivers using a GPS constellation simulator is detailed.
The NASA Goddard Space Flight Center (GSFC) Global Positioning System (GPS) applications test facility has been established within the GSFC Guidance Navigation and Control Center. The GPS test facility is currently housing the Global Simulation Systems Inc. (GSSI) STR2760 GPS satellite 40-channel attitude simulator and a STR4760 12-channel navigation simulator. The facility also contains a few other resources such as an atomic time standard test bed, a rooftop antenna platform and a radome. It provides a new capability for high dynamics GPS simulations of space flight that is unique within the aerospace community. The GPS facility provides a critical element for the development and testing of GPS based technologies i.e. position, attitude and precise time determination used on-board a spacecraft, suborbital rocket or balloon. The GPS simulator system is configured in a transportable rack and is available for GPS component development as well as for component, spacecraft subsystem and system level testing at spacecraft integration and test sites. The GPS facility has been operational since early 1996 and has been utilized by space flight projects carrying GPS experiments, such as the OrbView-2 and the Argentine SAC-A spacecrafts. The SAC-A pre-flight test data obtained by using the STR2760 simulator and the comparison with preliminary analysis of the GPS data from SAC-A telemetry are summarized. This paper describes pre-flight tests and simulations used to support a unique spaceborne GPS experiment. The GPS experiment mission objectives and the test program are described, as well as the GPS test facility configuration needed to verify experiment feasibility. Some operational and critical issues inherent in GPS receiver pre-flight tests and simulations using this GPS simulator, and test methodology are described. Simulation and flight data are presented. A complete program of pre-flight testing of spaceborne GPS receivers using a GPS constellation simulator is detailed.
From the very first days of human spaceflight, NASA has been conducting experiments in space to understand the effect of weightlessness on physical and chemically reacting systems. NASA Glenn Research Center (GRC) in Cleveland, Ohio has been at the forefront of this research looking at both fundamental studies in microgravity as well as experiments targeted at reducing the risks to long duration human missions to the moon, Mars, and beyond. In the current International Space Station (ISS) era, we now have an orbiting laboratory that provides the highly desired condition of long-duration microgravity. This allows continuous and interactive research similar to Earth-based laboratories. Because of these capabilities, the ISS is an indispensible laboratory for low gravity research. NASA GRC has been actively involved in developing and operating facilities and experiments on the ISS since the beginning of a permanent human presence on November 2, 2000. As the lead Center both Combustion, Fluid Physics, and Acceleration Measurement GRC has led the successful implementation of an Acceleration Measurement systems, the Combustion Integrated Rack (CIR), the Fluids Integrated Rack (FIR) as well as the continued use of other facilities on the ISS. These facilities have supported combustion experiments in fundamental droplet combustion fire detection fire extinguishment soot phenomena flame liftoff and stability and material flammability. The fluids experiments have studied capillary flow magneto-rheological fluids colloidal systems extensional rheology pool and nucleate boiling phenomena. In this paper, we provide an overview of the experiments conducted on the ISS over the past 12 years. We also provide a look to the future development. Experiments presented in combustion include areas such as droplet combustion, gaseous diffusion flames, solid fuels, premixed flame studies, fire safety, and super critical oxidation processes. In fluid physics, experiments are discussed in multiphase flows, capillary phenomena, and heat pipes. Finally in complex fluids, experiments in rheology and soft condensed materials will be presented.
Measurement of strength at high pressures is critical to understanding the behavior of materials subjected to extreme loading conditions. Recent developments have extended the pressure shear plate impact (PSPI) technique to the high-pressure regime. Such experiments provide a unique opportunity to extract the complete stress-strain behavior of materials at relatively high pressures. The modified technique includes a new fiber-optic heterodyne transverse velocity interferometer system and new analysis methods to account for the inelastic response of the anvil plates. In this study, PSPI experiments are conducted on oxygen-free high conductivity (OFHC) copper at pressures ranging from 10 to 43 GPa and at strain rates of ~10 5 s -1 . Complete stress-strain curves of copper are obtained using a hybrid methodology that relies on numerical simulations and particle velocity records gathered in these experiments. Experiments are conducted at similar pressures and strain rates using two types of anvils that undergo different levels of plastic strains: tool steel and tungsten carbide, to check the robustness of the hybrid method. The behavior of copper at these high pressures and strain rates is compared with previous literature data, and the effect of pressure and strain rate on the strength behavior of copper are discussed. Here, it was observed that the rate of change in yield strength change in pressure was 2.5 times the rate of change of shear modulus with pressure. The strength models that predict the response of copper at these extreme conditions are also examined and validated.
The Deep Underground Neutrino Experiment (DUNE) is a long-baseline neutrino oscillation experiment that aims at addressing key questions in neutrino physics in the next decades. Its scientific program includes the detection of the neutrino flux from a core-collapse supernova. The DUNE far detector will have four 17-kt mass liquid-argon (LAr) time-projection chamber (TPC) modules. ProtoDUNE Dual Phase (DP), a dual-phase LAr TPC with 300 t of active mass and 6 m of drift distance, was operated with cosmic muons in 2019-2020 as part of an R&D program at the CERN Neutrino Platform to demonstrate the feasibility of the technology at such a large scale. In a LAr TPC, the photon detection system (PDS) provides fundamental timing information and trigger capabilities. The PDS of ProtoDUNE-DP, which consisted of 36 photomultiplier tubes (PMTs), counted on a dedicated light calibration system (LCS) to monitor the PMT response. In this dissertation, the characterization and validation of the ProtoDUNE-DP PDS and LCS components before their installation will be reviewed, highlighting the results of general interest for experiments that use liquid noble gasses as target medium. The results from the stable performance of both systems in the detector during 15 months will be presented next as well as the studies on the scintillation light detection in ProtoDUNE-DP, where the collection of light produced in LAr at 7 m from the photosensors has been achieved for the first time. It is worth pointing out that the excellent LAr purity and the large size of the detector have enabled to develop a unique data-driven investigation on aspects that are critical for LAr-based experiments but that are not completely understood. The analyses cover the characterization of the low-energy background detected by the PDS, the quantification of the electric field impact on the light yield, the evaluation of the Rayleigh scattering affecting the light propagation, and the analysis of the PMT detection efficiency. The effect of the VUV reflectivity of the detector materials will be also discussed. In addition, the estimation of the cosmic muon flux crossing the TPC and the study of the observed light yield by the PDS will be reported. Finally, the results from the simulation-based study of the supernova burst trigger capability with the PDS of a 12.1-kt active mass dual-phase LAr TPC as the one proposed for DUNE will be summarized. Several configurations of reflective foils installed in the TPC to enhance the light collection will be compared.