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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

A CAD approach to magnetic bearing design

A design methodology has been developed at the Magnetic Bearing Research Laboratory for designing magnetic bearings using a CAD approach. This is used in the algorithm of an interactive design software package. The package is a design tool developed to enable the designer to simulate the entire process of design and analysis of the system. Its capabilities include interactive input/modification of geometry, finding any possible saturation at critical sections of the system, and the design and analysis of a control system that stabilizes and maintains magnetic suspension.

Jeyaseelan, M.↗
NASA NTRS2001

The AIRES Optical Design

AIRES (Airborne InfraRed Echelle Spectrometer) is the facility spectrometer for SOFIA (Stratospheric Observatory For Infrared Astronomy). AIRES is a long-slit (approximately 160 in) spectrometer designed to cover the 17 to 210-micron range with good sensitivity using three spectroscopic arrays. Initially, only the 30-130 micron, mid-wavelength array will be available. The instrument has a cryogenic K-mirror to perform field rotation and a slit-viewing camera (lambda < 28 microns, FOV = 160 in diameter) to image source morphology and verify telescope pointing. AIRES employs a large echelle grating to achieve a spectral resolving power (lambda/delta lambda) of approximately 1.0 x 10(exp 6)/lambda (sub mu), where lambda (sub mu) is the wavelength in microns. Hyperfine, Inc. has ruled and tested the AIRES' echelle; its wave-front error is 0.028 waves RMS (root mean square) at 10.6 microns. The instrument is housed in a liquid-helium cryostat which is constrained in diameter (approximately 1 m) and length (approximately 2 m) by the observatory. Hence, the length of the echelle (approximately 1.1 m) and the focal length of its collimator (approximately 5.2 m) severely drive the optical design and packaging. The final design uses diamond-turned aluminum optics and has up to 19 reflections inside the cryostat, depending on the optical path. This design was generated, optimized, and toleranced using Code V. The predicted performance is nearly diffraction-limited at 17 microns; the error budget is dominated by design residuals. Light loss due to slit rotation and slit curvature has been minimized. A thorough diffraction analysis with GLAD (G-Level Analysis Drawer) was used to size the mirrors and baffles; the internal light loss is shown to be a strong function of slit width.

Haas, Michael R.↗
NASA NTRS2013

Simulation Packages Expand Aircraft Design Options

In 2001, NASA released a new approach to computational fluid dynamics that allows users to perform automated analysis on complex vehicle designs. In 2010, Palo Alto, California-based Desktop Aeronautics acquired a license from Ames Research Center to sell the technology. Today, the product assists organizations in the design of subsonic aircraft, space planes, spacecraft, and high speed commercial jets.

Source record↗
NASA NTRS1983

Plastic-Sealed Hybrid Power Circuit Package

Proposed design for hybrid high-voltage power-circuit package uses molded plastic for hermetic sealing instead of glass-to-metal seal. New package used to house high-voltage regulators and solid-state switches for applications in aircraft, electric automobiles, industrial equipment, satellites, solarcell arrays, and other equipment in extreme environments.

Miller, W. N.↗
DOE OSTI2022

REGULATORY TESTING AND 3D SCANNING METHODOLOGY OF THE DPP-1 TYPE SHIPPING CONTAINER FOR NCT AND HAC TESTS

The safe transportation of radioactive material using appropriately designed and certified transportation packages is important to protect the public and environment. In the United States of America all transportation of radioactive material is regulated by the Department of Transportation (DOT) along with input by the Nuclear Regulatory Commission (NRC). All packages that contain radioactive material requires that it be transported and regulated by the requirements set by the DOT Class 7 hazardous material transportation. Federal regulations place strict administrative controls on the transport of radioactive materials. The two main goals for transporting radioactive materials are 1. Safety should be the primarily focused on the package because it is the first line of defense. 2. Package integrity should be directly related to the degree of the hazard of the radioactive material contents. The two-part goal ensures that the right package is used. Type B packages are designed to transport radioactive materials with the highest level of radioactivity. Examples of material transported in Type B packagings include spent nuclear fuel, high-level radioactive waste, and high concentrations of other radioactive materials. The purpose of this test protocol is to determine the effects of drop and thermal testing on package performance in a Type B shipping package (DPP-1). Required physical tests for the DPP-1 package include free drop, crush, puncture, penetration, compression, vibration, water spray, water immersion, and thermal. The preparation, regulatory testing, and post-test evaluation of a Type B shipping package tested to the 10 CFR 71.71 and 10 CFR 71.73 requirements will be presented. Six packages were tested and the responses when subjected to the HAC sequence of free drop, puncture, and thermal tests according to 10 CFR 71.73(c)(1), (c)(2), (c)(3) and (c)(4) were measured. The Free Drop, Crush and Puncture tests were performed at the NTRC in Knoxville, TN, and the Thermal tests were performed Southwest Research Institute in San Antonio, TX. The test units were subjected to a pre-operational leak testing before the NCT and HAC tests and a post-operational leak test and a helium leak test once regulatory testing was complete. Finally, all test units were scanned with a handheld blue light scanner to capture a 3D CAD geometry of the test units in the deformed shape. The handheld scanner provided the most effective and reliable way to acquire accurate 3D measurements of the test unit. The scanned geometry was sectioned in areas with deformation and the cross-section profile was measured to determine accurate and repeatable results of the deformed shape of the test units.

Martinez, Oscar↗
DOE OSTI2020

Parametric Design Study of a Power Electronics Package

The lifetime of a power electronics package is, to a large extent, determined by the reliability of its bonded interfaces under major loading conditions in an operational environment. Based on the application-level requirements of the package, bonded interface material is selected based on the results obtained from accelerated tests such as thermal cycling and power cycling. In addition to evaluating the reliability through accelerated tests, it is important to consider the impact of other component layers on the thermomechanical performance of the interface material, both from a material and geometric perspective. The co-efficient of thermal expansion (CTE) mismatch introduced by the use of different materials within a package and its structural design plays a critical role in determining the interface material reliability. In this paper, we present the results of a parametric modeling study of a power electronics package under thermal cycling in which the materials and geometric design of the different component layers were varied with respect to a baseline design to understand their impact on the reliability of the interface material. We chose the volume-averaged strain energy density per cycle computed at the corner region of the interface material as the metric for the reliability comparisons. Our results indicate that in addition to the CTE mismatch, the stiffness of individual component layers has a major impact on reliability. Among the different baseplates that we studied, aluminum silicon-carbide baseplates offered superior reliability over their copper and aluminum counterparts. We also found that the magnitude of the impact of stiffness variation—amongst the adjacent layers—on the reliability of the solder joint is dependent on the inherent CTE mismatch between the layers.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Parametric Design Study of a Power Electronics Package for Improving Solder Joint Reliability

The lifetime of a power electronics package is, to a large extent, determined by the reliability of its bonded interfaces under major loading conditions in an operational environment. Based on the application-level requirements of the package, bonded interface material is selected based on the results obtained from accelerated tests such as thermal cycling and power cycling. In addition to evaluating the reliability through accelerated tests, it is important to consider the impact of other component layers on the thermomechanical performance of the interface material, both from a material and geometric perspective. The co-efficient of thermal expansion (CTE) mismatch introduced by the use of different materials within a package and its structural design plays a critical role in determining the interface material reliability. In this paper, we present the results of a parametric modeling study of a power electronics package under thermal cycling in which the materials and geometric design of the different component layers were varied with respect to a baseline design to understand their impact on the reliability of the interface material. We chose the volume-averaged strain energy density per cycle computed at the corner region of the interface material as the metric for the reliability comparisons. Our results indicate that in addition to the CTE mismatch, the stiffness of individual component layers has a major impact on reliability. Among the different baseplates that we studied, aluminum silicon-carbide baseplates offered superior reliability over their copper and aluminum counterparts. We also found that the magnitude of the impact of stiffness variation—amongst the adjacent layers—on the reliability of the solder joint is dependent on the inherent CTE mismatch between the layers.

47 OTHER INSTRUMENTATION↗
NASA NTRS2007

Overview of NASA Langley's Piezoelectric Ceramic Packaging Technology and Applications

Over the past decade, NASA Langley Research Center (LaRC) has developed several actuator packaging concepts designed to enhance the performance of commercial electroactive ceramics. NASA LaRC focused on properly designed actuator and sensor packaging for the following reasons, increased durability, protect the working material from the environment, allow for proper mechanical and electrical contact, afford "ready to use" mechanisms that are scalable, and develop fabrication methodology applicable to any active material of the same physical class. It is more cost effective to enhance or tailor the performance of existing systems, through innovative packaging, than to develop, test and manufacture new materials. This approach led to the development of several solid state actuators that include THUNDER, the Macrofiber Composite or (MFC) and the Radial Field Diaphragm or (RFD). All these actuators are fabricated using standard materials and processes derived from earlier concepts. NASA s fabrication and packaging technology as yielded, piezoelectric actuators and sensors that are easy to implement, reliable, consistent in properties, and of lower cost to manufacture in quantity, than their predecessors (as evidenced by their continued commercial availability.) These piezoelectric actuators have helped foster new research and development in areas involving computational modeling, actuator specific refinements, and engineering system redesign which led to new applications for piezo-based devices that replace traditional systems currently in use.

Bryant, Robert G.↗
NASA NTRS2014

A Compact Two-Stage 120 W GaN High Power Amplifier for SweepSAR Radar Systems

This work presents the design and measured results of a fully integrated switched power two-stage GaN HEMT high-power amplifier (HPA) achieving 60% power-added efficiency at over 120Woutput power. This high-efficiency GaN HEMT HPA is an enabling technology for L-band SweepSAR interferometric instruments that enable frequent repeat intervals and high-resolution imagery. The L-band HPA was designed using space-qualified state-of-the-art GaN HEMT technology. The amplifier exhibits over 34 dB of power gain at 51 dBm of output power across an 80 MHz bandwidth. The HPA is divided into two stages, an 8 W driver stage and 120 W output stage. The amplifier is designed for pulsed operation, with a high-speed DC drain switch operating at the pulsed-repetition interval and settles within 200 ns. In addition to the electrical design, a thermally optimized package was designed, that allows for direct thermal radiation to maintain low-junction temperatures for the GaN parts maximizing long-term reliability. Lastly, real radar waveforms are characterized and analysis of amplitude and phase stability over temperature demonstrate ultra-stable operation over temperature using integrated bias compensation circuitry allowing less than 0.2 dB amplitude variation and 2 deg phase variation over a 70 C range.

Thrivikraman, Tushar↗
NASA NTRS1998

Advanced Spacesuit Portable Life Support System Packaging Concept Mock-Up Design & Development

A concentrated development effort was begun at NASA Johnson Space Center to create an advanced Portable Life Support System (PLSS) packaging concept. Ease of maintenance, technological flexibility, low weight, and minimal volume are targeted in the design of future micro-gravity and planetary PLSS configurations. Three main design concepts emerged from conceptual design techniques and were carried forth into detailed design, then full scale mock-up creation. "Foam", "Motherboard", and "LEGOtm" packaging design concepts are described in detail. Results of the evaluation process targeted maintenance, robustness, mass properties, and flexibility as key aspects to a new PLSS packaging configuration. The various design tools used to evolve concepts into high fidelity mock ups revealed that no single tool was all encompassing, several combinations were complimentary, the devil is in the details, and, despite efforts, many lessons were learned only after working with hardware.

O''Connell, Mary K.↗
NASA NTRS1972

Apollo experience report: Thermal design of Apollo lunar surface experiments package

The evolution of the thermal design of the Apollo lunar surface experiments package central station from the basic concept to the final flight hardware is discussed, including results of development, prototype, and qualification tests that were used to verify that the flight hardware would operate adequately on the lunar surface. In addition, brief discussions of the thermal design of experiments included in the experiments package are presented. The flight thermal performance is compared with analytical results and thermal-vacuum test results, and design modifications for future lunar surface experiment packages are presented.

Harris, R. S., Jr.↗
NASA NTRS1992

Helium compressors for closed-cycle, 4.5-Kelvin refrigerators

An improved helium compressor for traveling-wave maser and closed-cycle refrigerator systems was developed and is currently being supplied to the DSN. This new 5-hp compressor package is designed to replace the current 3-hp DSN compressors. The new compressor package was designed to retrofit into the existing 3-hp compressor frame and reuse many of the same components, therefore saving the cost of documenting and fabricating these components when implementing a new 5-hp compressor.

Hanson, T. R.↗
NASA NTRS1987

Space station power semiconductor package

A package of high-power switching semiconductors for the space station have been designed and fabricated. The package includes a high-voltage (600 volts) high current (50 amps) NPN Fast Switching Power Transistor and a high-voltage (1200 volts), high-current (50 amps) Fast Recovery Diode. The package features an isolated collector for the transistors and an isolated anode for the diode. Beryllia is used as the isolation material resulting in a thermal resistance for both devices of .2 degrees per watt. Additional features include a hermetical seal for long life -- greater than 10 years in a space environment. Also, the package design resulted in a low electrical energy loss with the reduction of eddy currents, stray inductances, circuit inductance, and capacitance. The required package design and device parameters have been achieved. Test results for the transistor and diode utilizing the space station package is given.

Balodis, Vilnis↗