Component testing of a 30-centimeter diameter electron bombardment thruster
Performance tests of critical components on mercury electron bombardment thruster
Bechtel, R. T.↗
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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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Operation and testing of Mark 10 Mod 3 underwater breathing apparatus
Performance tests on a closed circuit, mixed gas underwater breathing apparatus are reported. The equipment is designed to provide a minimum diving duration of four hours at 1500 ft below sea surface; it senses oxygen partial pressure in the breathing gas mix and controls oxygen content of the breathing gas within narrow limits about a preset value. The breathing circuit subsystem provides respirable gas to the diver and removes carbon dioxide and moisture from the expired gas. Test results indicate undesirable variations in oxygen partial pressure with oxygen addition and insufficient carbon dioxide absorption.
Milwee, W. I., Jr.↗
Modification, static testing and delivery of one servoactuator
The development and performance testing of a servoactuator device are discussed. The detailed information includes the following: (1) modification description, (2) test data to include analyses, test procedures, and test data, (3) conclusions, and (4) recommendations. Diagrams of the servoactuator and photographs of the test equipment are presented. Descriptions of optimized system configurations are developed.
Hart, K. E.↗
Role of Wind Tunnels and Computer Codes in the Certification and Qualification of Rotorcraft for Flight in Forecast Icing
The cost and time to certify or qualify a rotorcraft for flight in forecast icing has been a major impediment to the development of ice protection systems for helicopter rotors. Development and flight test programs for those aircraft that have achieved certification or qualification for flight in icing conditions have taken many years, and the costs have been very high. NASA, Sikorsky, and others have been conducting research into alternative means for providing information for the development of ice protection systems, and subsequent flight testing to substantiate the air-worthiness of a rotor ice protection system. Model rotor icing tests conducted in 1989 and 1993 have provided a data base for correlation of codes, and for the validation of wind tunnel icing test techniques. This paper summarizes this research, showing test and correlation trends as functions of cloud liquid water content, rotor lift, flight speed, and ambient temperature. Molds were made of several of the ice formations on the rotor blades. These molds were used to form simulated ice on the rotor blades, and the blades were then tested in a wind tunnel to determine flight performance characteristics. These simulated-ice rotor performance tests are discussed in the paper. The levels of correlation achieved and the role of these tools (codes and wind tunnel tests) in flight test planning, testing, and extension of flight data to the limits of the icing envelope are discussed. The potential application of simulated ice, the NASA LEWICE computer, the Sikorsky Generalized Rotor Performance aerodynamic computer code, and NASA Icing Research Tunnel rotor tests in a rotorcraft certification or qualification program are also discussed. The correlation of these computer codes with tunnel test data is presented, and a procedure or process to use these methods as part of a certification or qualification program is introduced.
Flemming, Robert J.↗
Statistical analysis of SSME system data
A statistical methodology to enhance the Space Shuttle Main Engine (SSME) performance prediction accuracy is proposed. This methodology was to be used in conjunction with existing SSME performance prediction computer codes to improve parameter prediction accuracy and to quantify that accuracy. However, after a review of related literature, researchers concluded that the proposed problem required a coverage of areas such as linear and nonlinear system theory, measurement theory, statistics, and stochastic estimation. Since state space theory is the foundation for a more complete study of each of the before mentioned areas, these researchers chose to refocus emphasis to cover the more specialized topic of state vector estimation procedures. State vector estimation was also selected because of current and future concerns by NASA for SSME performance evaluation; i.e., there is a current interest in an improved evaluation procedure for actual SSME post flight performance as well as for post static test performance of a single SSME. A current investigation of analytical methods may be used to improve test stand failure detection. This paper considers the issue of post flight/test state variable reconstruction through the application of observations made on the output of the Space Shuttle propulsion system. Rogers used the Kalman filtering procedure to reconstruct the state variables of the Space Shuttle propulsion system. An objective of this paper is to give the general setup of the Kalman filter and its connection to linear regression. A second objective is to examine the reconstruction methodology for application to the reconstruction of the state vector of a single Space Shuttle Main Engine (SSME) by using static test firing data.
Temple, Enoch C.↗
Qualification of the RSRM case membrane case-to-insulation bondline inspection using the Thiokol Corporation ultrasonic RSRM bondline inspection system
Qualification testing of Combustion Engineering's AMDATA Intraspect/98 Data Acquisition and Imaging System that applies to the redesigned solid rocket motor (RSRM) case membrane case-to-insulation bondline inspection was performed. Testing was performed at M-67, the Thiokol Corp. RSRM Assembly Facility. The purpose of the inspection was to verify the integrity of the case membrane case-to-insulation bondline. The case membrane scanner was calibrated on the redesigned solid rocket motor case segment calibration standard, which had an intentional 1.0 by 1.0 in. case-to-insulation unbond. The case membrane scanner was then used to scan a 20 by 20 in. membrane area of the case segment. Calibration of the scanner was then rechecked on the calibration standard to ensure that the calibration settings did not change during the case membrane scan. This procedure was successfully performed five times to qualify the unbond detection capability of the case membrane scanner.
Cook, M.↗
9977 type b packaging internal data collection feasibility testing - magnetic field communications
The objective of this report is to document the findings from proof-of-concept testing performed by the Savannah River National Laboratory (SRNL) R&D Engineering and Visible Assets, Inc. for the DOE Packaging Certification Program (PCP) to determine if RuBee (IEEE 1902.1) tags and readers could be used to provide a communication link from within a drum-style DOE certified Type B radioactive materials packaging. A Model 9977 Type B Packaging was used to test the read/write capability and range performance of a RuBee tag and reader. Testing was performed with the RuBee tags placed in various locations inside the packaging including inside the drum on the outside of the lid of the containment vessel and also inside of the containment vessel. This report documents the test methods and results. A path forward will also be recommended.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Lightweight composite mirror analysis and testing
The Jet Propulsion Laboratory InterDisciplinary Model for precision composite structures is described along with the HAVOC composite computer code used to study laminate mirror facesheets. The composite mirror panel thermal behavior is described in addition to structural and optical characteristics. Environmental mirror performance testing and performance test/prediction correlation are covered.
Helms, R. G.↗
Dielectric breakdown in a dilute plasma.
Description of tests performed to determine the effects of high voltages on dielectrics that are to insulate solar cell arrays operating at voltages up to 16 kV from the electrically active plasma of the space environment at 500 km altitude. The tests were performed on dielectrics considered for this application at positive bias voltages as high as 20 kV dc relative to ground in an argon plasma with electron number densities of approximately one million per cu cm. Teflon specimens displayed higher breakdown voltages than all other dielectrics tested.
Mckinzie, D. J., Jr.↗
Experimental and analytical comparison of flowfields in a 110 N (25 Lbf) H2/O2 rocket
A gaseous hydrogen/gaseous oxygen 110 N (25 lbf) rocket has been examined through the RPLUS code using the full Navier-Stokes equations with finite-rate chemistry. Performance tests were conducted on the rocket in an altitude test facility. Preliminary parametric analyses have been performed for a range of mixture ratios and fuel film cooling percentages. It is shown that the computed values of specific impulse and characteristic exhaust velocity follow the trend of the experimental data. Specific impulse computed by the code is lower than the comparable test values by about two to three percent. The computed characteristic exhaust velocity values are lower than the comparable test values by three to four percent. Thrust coefficients computed by the code are found to be within two percent of the measured values. It is concluded that the discrepancy between computed and experimental performance values could not be attributed to experimental uncertainty.
Reed, Brian D.↗
Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets
The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to each the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fouriers Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at 76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.
Structural attachments↗
The second generation Singapore high resolution proton beam writing facility
A new proton beam focusing facility, designed for proton beam writing (PBW) applications has been tested. PBW allows for proximity free structuring of high aspect ratio, high-density 3D nanostructures. The new facility is designed around OM52 compact quadrupole lenses capable of operating in a variety of high demagnification configurations. Performance tests show that proton beams can be focused down to 19.0 x 29.9 nm{sup 2} and single line scans show a beam width of 12.6 nm. The ultimate goal of sub 10 nm structuring with MeV protons will be discussed.
43 PARTICLE ACCELERATORS↗
Validation of a fault-tolerant multiprocessor: Baseline experiments and workload implementation
In the future, aircraft must employ highly reliable multiprocessors in order to achieve flight safety. Such computers must be experimentally validated before they are deployed. This project outlines a methodology for validating reliable multiprocessors. The methodology begins with baseline experiments, which tests a single phenomenon. As experiments progress, tools for performance testing are developed. The methodology is used, in part, on the Fault Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB facility. Experiments are designed to evaluate the fault-free performance of the system. Presented are the results of interrupt baseline experiments performed on FTMP. Interrupt causing exception conditions were tested, and several were found to have unimplemented interrupt handling software while one had an unimplemented interrupt vector. A synthetic workload model for realtime multiprocessors is then developed as an application level performance analysis tool. Details of the workload implementation and calibration are presented. Both the experimental methodology and the synthetic workload model are general enough to be applicable to reliable multiprocessors beside FTMP.
Feather, Frank↗
Elastomer mounted rotors - An alternative for smoother running turbomachinery
This paper describes the design of elastomeric bearing supports for a rotor built to simulate the power turbine of an advanced gas turbine engine which traverses two bending critical speeds. The elastomer dampers were constructed so as to minimize rotor dynamic response at the critical speeds. Results are presented of unbalance response tests performed with two different elastomer materials. These results showed that the resonances on the elastomer-mounted rotor were well damped for both elastomer materials and showed linear response to the unbalance weights used for response testing. Additional tests were performed using solid steel supports at either end (hand-mounted), which resulted in drastically increased sensitivity and nonlinear response, and with steel supports in one end of the rotor and the elastomer at the other, which yielded results which were between the soft- and hard-mounted cases. It is concluded that elastomeric supports are a viable alternative to other methods of mounting flexible rotors, that damping was well in excess of predictions and that elastomeric supports are tolerant of small rotor misalignments.
Tecza, J. A.↗
T-1072: Beam test for muon strips
Beam test for muon strips is an experiment to measure the efficiency, time resolution and longitudinal position resolution of scintillator strips for a muon system at future colliders. The muon system at future colliders is envisioned as several layers of position-sensitive detectors embedded in the iron flux-return yoke of the solenoidal magnet. The role of the muon system is primarily the identification of muons and track matching to the central tracker, besides serving as the tail catcher for the hadronic showers that penetrate beyond the hadron calorimetry. Previous tests performed at Fermilab with cosmic muons have shown that scintillators with wavelength-shifting (WLS) fibers and a SiPM readout offer promising performance (NIM A 823, 2016, pp.120-125). The purpose of the present beam tests is to determine the performance parameters with better accuracy. The measurement setup is schematically presented in Fig. 1. The length of the tested strips will vary between 1 m and 2 m. The scintillator strip to be tested will be placed horizontally perpendicular to the beam on a platform in the area behind the beam dump of MT6.2. Two fast scintillators S1 and S2 with vacuum PMT readout will be placed in front and after the tested strip in the beam. The distance between S1 and S2 is 1 m. One fast scintillator strip S3 will be placed in beam immediately in front of the tested strip, perpendicular to the tested strip. A rack with a CAMAC crate and two NIM crates will be used for the data acquisition. The data collection will be performed and monitored from a PC with USB connection to the CAMAC Crate controller.
43 PARTICLE ACCELERATORS↗
Space Fission Propulsion Testing and Development Progress
Successful development of space fission systems will require an extensive program of affordable and realistic testing. In addition to tests related to design/development of the fission system, realistic testing of the actual flight unit must also be performed. Testing can be divided into two categories, non-nuclear tests and nuclear tests. Full power nuclear tests of space fission systems we expensive, time consuming, and of limited use, even in the best of programmatic environments. If the system is designed to operate within established radiation damage and fuel burn up limits while simultaneously being designed to allow close simulation of heat from fission using resistance heaters, high confidence in fission system performance and lifetime can be attained through a series of non-nuclear tests. Non-nuclear tests are affordable and timely, and the cause of component and system failures can be quickly and accurately identified. MSFC is leading a Safe Affordable Fission Engine (SAFE) test series whose ultimate goal is the demonstration of a 300 kW flight configuration system using non-nuclear testing. This test series is carried out in collaboration with other NASA centers, other government agencies, industry, and universities. If SAFE-related nuclear tests are desired they will have a high probability of success and can be performed at existing nuclear facilities. The paper describes the SAFE non-nuclear test series, which includes test article descriptions, test results and conclusions, and future test plans.
VanDyke, Melissa↗
A Hybrid Parachute Simulation Environment for the Orion Parachute Development Project
A parachute simulation environment (PSE) has been developed that aims to take advantage of legacy parachute simulation codes and modern object-oriented programming techniques. This hybrid simulation environment provides the parachute analyst with a natural and intuitive way to construct simulation tasks while preserving the pedigree and authority of established parachute simulations. NASA currently employs four simulation tools for developing and analyzing air-drop tests performed by the CEV Parachute Assembly System (CPAS) Project. These tools were developed at different times, in different languages, and with different capabilities in mind. As a result, each tool has a distinct interface and set of inputs and outputs. However, regardless of the simulation code that is most appropriate for the type of test, engineers typically perform similar tasks for each drop test such as prediction of loads, assessment of altitude, and sequencing of disreefs or cut-aways. An object-oriented approach to simulation configuration allows the analyst to choose models of real physical test articles (parachutes, vehicles, etc.) and sequence them to achieve the desired test conditions. Once configured, these objects are translated into traditional input lists and processed by the legacy simulation codes. This approach minimizes the number of sim inputs that the engineer must track while configuring an input file. An object oriented approach to simulation output allows a common set of post-processing functions to perform routine tasks such as plotting and timeline generation with minimal sensitivity to the simulation that generated the data. Flight test data may also be translated into the common output class to simplify test reconstruction and analysis.
Moore, James W.↗
A convenient miniature test platform for polyelectrolyte membrane fuel-cell research
We report a simple and convenient small-scale fuel-cell test platform was created from a commercial compression fitting and graphite rod current collectors and used to conduct diagnostic tests on disk-shaped membrane-electrode assemblies (MEAs) fabricated from Nafion membranes and Nafion-impregnated platinum-on-carbon-cloth anodes and cathodes. A key advantage of this test platform is that it requires very little material, perhaps just a few milligrams, to conduct a fuel-cell test on a supported catalyst. Electrochemically-active surface area (ECSA) values for supported platinum on carbon-cloth electrodes were obtained by in-situ (in the fuel cell) and ex-situ (in liquid electrolyte) cyclic voltammetry on similarly-prepared electrodes, and values obtained by these methods were compared with each other to estimate the fraction of platinum catalyst contacted by the Nafion ionomer in the fuel-cell cathode. Polarization curves were acquired under controlled-potential conditions using slow-scan cyclic and sampled-current voltammetry and potential-step amperometry methods with conventional electroanalytical instrumentation. Tests performed using this platform are complementary to rotating disk electrode (RDE) voltammetry tests which also allow for catalyst testing on small amounts of material, albeit in the presence of liquid electrolyte, and are commonly used for initial screening of new fuel-cell catalysts. They are also complementary to conventional fuel-cell testing that is commonly performed on MEAs having active areas more than 100 times larger than that in the present cells.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗