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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Thermal Vacuum/Balance Test Results of Swift BAT with Loop Heat Pipe Thermal System

The Swift Burst Alert Telescope (BAT) Detector Array is thermally well coupled to eight constant conductance heat pipes (CCHPs) embedded in the Detector Array Plate PAP), and two loop heat pipes (LHPs) transport heat from the CCHPs to a radiator. The CCHPs have ammonia as the working fluid and the LHPs have propylene as the working fluid. Precision heater controllers, which have adjustable set points in flight, are used to control the LHP compensation chamber and Detector Array xA1 ASIC temperatures. The radiator has AZ-Tek's AZW-LA-II low solar absorptance white paint as the thermal coating, and is located on the anti-sun side of the spacecraft. A thermal balance (T/B) test on the BAT was successfully completed. It validated that the thermal design satisfies the temperature requirements of the BAT in the flight thermal environments. Instrument level and observatory level thermal vacuum (TN) cycling tests of the BAT Detector Array by using the LHP thermal system were successfully completed. This paper presents the results of the T/B test and T N cycling tests.

Choi, Michael K.↗
NASA NTRS1973

Space vehicle integrated thermal protection/structural/meteoroid protection system, volume 1

A program was conducted to determine the merit of a combined structure/thermal meteoroid protection system for a cryogenic vehicle propulsion module. Structural concepts were evaluated to identify least weight designs. Thermal analyses determined optimum tank arrangements and insulation materials. Meteoroid penetration experiments provided data for design of protection systems. Preliminary designs were made and compared on the basis of payload capability. Thermal performance tests demonstrated heat transfer rates typical for the selected design. Meteoroid impact tests verified the protection characteristics. A mockup was made to demonstrate protection system installation. The best design found combined multilayer insulation with a truss structure vehicle body. The multilayer served as the thermal/meteoroid protection system.

Bartlett, D. H.↗
NASA NTRS1981

Simplified thermal analyzer

Simplified Shuttle Payload Thermal Analyzer (SSPTA) aids in evaluating thermal design of instruments to be flown in Space Shuttle cargo bay. It is collection of programs that are currently used in thermal analysis of spacecraft, modified for quick, preliminary analysis of payloads. Although designed primarily to analyze Shuttle payloads, it can be easily used for thermal analysis in other situations.

Coyle, M. J.↗
NASA NTRS1987

Shuttle payload bay thermal environments: Summary and conclusion report for STS Flights 1-5

The thermal data for the payload bay of the first five shuttle flights is summarized and the engineering evaluation of that data is presented. After a general discussion on mission profiles and vehicle configurations, the thermal design and flight instrumentation systems of the payload bay are described. The thermal flight data sources and a categorization of the data are then presented. A thermal flight data summarization section provides temperature data for the five phases of a typical mission profile. These are: prelaunch, ascent, on-orbit, entry and postlanding. The thermal flight data characterization section encompasses this flight data for flight to flight variations, payload effects, temperature ranges, and other variations. Discussion of the thermal environment prediction models in use by industry and various NASA Centers, and the results predicted by these models, is followed by an evaluation of the correlation between the actual flight data and the results predicted by the models. Finally, the available thermal data are evaluated from the viewpoint of the user concerned with establishing the thermal environment in the payload bay. The data deficiencies are discussed and recommendations for their elimination are presented.

Fu, J. H.↗
DOE OSTI2024

Boiling-Water Reactor Testing Capability in the Advanced Test Reactor

I-Loop is an irradiation facility that is currently being installed at the Advanced Test Reactor. It is a two-loop test facility capable of performing Light Water Reactor (LWR) irradiations in prototypic coolant conditions. The two loops are being installed to be capable of both Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR) pressure, temperature, and chemistry environments. Each loop is nominally dedicated as a BWR or PWR for simplicity of operations. In-reactor water loop testing that an I-Loop provides is key to the deployment of new accident tolerant fuel technologies and other advanced LWR fuel concepts. Currently, pressurized water loops are the only testing facilities available to test BWR fuel concepts. Their test environments are non-prototypic at higher pressure/temperature and at single-phase fluid flow conditions. This void in the LWR test bed capabilities is one that the I-Loop is uniquely situated to provide. This report discusses the mechanical design, thermal hydraulic calculations, and neutronic calculations of a proposed standard experiment of accident tolerant BWR fuel concepts. Mechanical design examines the geometry and features of the main components. Thermal hydraulic calculations examine the modeling and results of the two-phase flow options available. Lastly, neutronic calculations examine the Monte Carlo analysis of enrichment, heat rates, and flux spectrum.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS1985

Superconducting magnet

Extensive computer based engineering design effort resulted in optimization of a superconducting magnet design with an average bulk current density of approximately 12KA/cm(2). Twisted, stranded 0.0045 inch diameter NbTi superconductor in a copper matrix was selected. Winding the coil from this bundle facilitated uniform winding of the small diameter wire. Test coils were wound using a first lot of the wire. The actual packing density was measured from these. Interwinding voltage break down tests on the test coils indicated the need for adjustment of the wire insulation on the lot of wire subsequently ordered for construction of the delivered superconducting magnet. Using the actual packing densities from the test coils, a final magnet design, with the required enhancement and field profile, was generated. All mechanical and thermal design parameters were then also fixed. The superconducting magnet was then fabricated and tested. The first test was made with the magnet immersed in liquid helium at 4.2K. The second test was conducted at 2K in vacuum. In the latter test, the magnet was conduction cooled from the mounting flange end.

Source record↗
NASA NTRS1990

Ongoing nickel-hydrogen energy storage device testing at George C. Marshall Space Flight Center

The primary objective of the testing is to characterize Ni-H2 cells for successful integration into the electrical power system (EPS) of the Hubble Space Telescope (HST). A broad spectrum of Ni-H2 design technology is encompassed by the testing configurations; tests include cells with dates of manufacture as early as 1976. The database includes cells of varied storage times, capacity, plate design, stack design, terminal configuration, pressure vessel thickness, separator material, potassium hydroxide (KOH) concentration, and thermal control. Currently, 196 Ni-H2 cells are being tested, grouped as follows: 12 RNH-35-3, 14 RNH-30-1, 22 HST cells (1 battery, flight spare lot), 132 HST cells (6 batteries, test modules 1 and 2, called TM1 and TM2), 12 HST cells (3 four-cell packs, TM1, TM2, flight spare module FSM), and 4 HST cells (engineering lot). In addition to the characterization and life testing, an extensive thermal vacuum and purge test was conducted in November 1989 and February 1990 using the HST FSM (3 batteries composed of 69 HST cells from the flight spare lot) to help verify thermal design. A report is presented of the progress, significant findings, and future objectives of the testing.

Lowery, John E.↗
NASA NTRS2001

Thermal Performance of the Hubble Space Telescope (HST) Solar Array-3 During the Disturbance Verification Test (DVT)

The Hubble Space Telescope (HST) is one of NASA's most productive astronomical observatories. Launched in 1990, the HST continues to gather scientific data to help scientists around the world discover amazing wonders of the universe. To maintain HST in the fore front of scientific discoveries, NASA has routinely conducted servicing missions to refurbish older equipment as well as to replace existing scientific instruments with better, more powerful instruments. In early 2002, NASA will conduct its fourth servicing mission to the HST. This servicing mission is named Servicing Mission 3B (SM3B). During SM3B, one of the major refurbishment efforts will be to install new rigid-panel solar arrays as a replacement for the existing flexible-foil solar arrays. This is necessary in order to increase electrical power availability for the new scientific instruments. Prior to installing the new solar arrays on HST, the HST project must be certain that the new solar arrays will not cause any performance degradations to the observatory. One of the major concerns is any disturbance that can cause pointing Loss of Lock (LOL) for the telescope. While in orbit, the solar-array temperature transitions quickly from sun to shadow. The resulting thermal expansion and contraction can cause a "mechanical disturbance" which may result in LOL. To better characterize this behavior, a test was conducted at the European Space Research and Technology Centre (ESTEC) in the Large Space Simulator (LSS) thermal-vacuum chamber. In this test, the Sun simulator was used to simulate on-orbit effects on the solar arrays. This paper summarizes the thermal performance of the Solar Array-3 (SA3) during the Disturbance Verification Test (DVT). The test was conducted between 26 October 2000 and 30 October 2000. Included in this paper are: (1) brief description of the SA3's components and its thermal design; (2) a summary of the on-orbit temperature predictions; (3) pretest thermal preparations; (4) a description of the chamber and thermal monitoring sensors; and (6) presentation of test thermal data results versus flight predictions.

Nguyen, Daniel H.↗
NASA NTRS2008

JWST ISIM Harness Thermal Evaluation

The James Webb Space Telescope (JWST) will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for 2013. JWST wl1 be the premier observatory of the next decade serving thousands of astronomers worldwide. The Integrated Science Instrument Module (ISIM) is the unit that will house thc four main JWST instruments. The ISIM enclosure passively cooled to 37 Kelvin and has a tightly managed thermal budget. A significant portion of the ISIM heat load is due to parasitic heat gains from the instrument harnesses. These harnesses provide a thermal path from the Instrument Electronics Control (IEC) to the ISIM. Because of the impact of this load to the ISIM thermal design, understanding the harness parasitic heat gains is critical. To this effect, a thermal test program has been conducted in order to characterize these parasitic loads and verify harness thermal models. Recent parasitic heat loads tests resulted in the addition of a dedicated multiple stage harness radiator. In order for the radiator to efficiently reject heat from the harness, effective thermal contact conductance values for multiple harnesses had to be determined. This presentation will describe the details and the results of this test program.

Kobel, Mark↗
NASA NTRS1998

X-33 Base Region Thermal Protection System Design Study

The X-33 is an advanced technology demonstrator for validating critical technologies and systems required for an operational Single-Stage-to-Orbit (SSTO) Reusuable Launch Vehicle (RLV). Currently under development by a unique contractor/government team led by Lockheed- Martin Skunk Works (LMSW), and managed by Marshall Space Flight Center (MSFC), the X-33 will be the prototype of the first new launch system developed by the United States since the advent of the space shuttle. This paper documents a design trade study of the X-33 base region thermal protection system (TPS). Two candidate designs were evaluated for thermal performance and weight. The first candidate was a fully reusable metallic TPS using Inconel honeycomb panels insulated with high temperature fibrous insulation, while the second was an ablator/insulator sprayed on the metallic skin of the vehicle. The TPS configurations and insulation thickness requirements were determined for the predicted main engine plume heating environments and base region entry aerothermal environments. In addition to thermal analysis of the design concepts, sensitivity studies were performed to investigate the effect of variations in key parameters of the base TPS analysis.

Lycans, Randal W.↗
NASA NTRS1988

Thermal/structural design verification strategies for large space structures

Requirements for space structures of increasing size, complexity, and precision have engendered a search for thermal design verification methods that do not impose unreasonable costs, that fit within the capabilities of existing facilities, and that still adequately reduce technical risk. This requires a combination of analytical and testing methods. This requires two approaches. The first is to limit thermal testing to sub-elements of the total system only in a compact configuration (i.e., not fully deployed). The second approach is to use a simplified environment to correlate analytical models with test results. These models can then be used to predict flight performance. In practice, a combination of these approaches is needed to verify the thermal/structural design of future very large space systems.

Benton, David↗
DOE OSTI2024

A nanoscale photonic thermal transistor for sub-second heat flow switching

Abstract Control of heat flow is critical for thermal logic devices and thermal management and has been explored theoretically. However, experimental progress on active control of heat flow has been limited. Here, we describe a nanoscale radiative thermal transistor that comprises of a hot source and a cold drain (both are ~250 nm-thick silicon nitride membranes), which are analogous to the source and drain electrodes of a transistor. The source and drain are in close proximity to a vanadium oxide (VO x )-based planar gate electrode, whose dielectric properties can be adjusted by changing its temperature. We demonstrate that when the gate is located close ( < ~1 µm) to the source-drain device and undergoes a metal-insulator transition, the radiative heat transfer between the source and drain can be changed by a factor of three. More importantly, our nanomembrane-based thermal transistor features fast switching times ( ~ 500 ms as opposed to minutes for past three-terminal thermal transistors) due to its small thermal mass. Our experiments are supported by detailed calculations that highlight the mechanism of thermal modulation. We anticipate that the advances reported here will open new opportunities for designing thermal circuits or thermal logic devices for advanced thermal management.

42 ENGINEERING↗
DOE OSTI2024

Conceptual design of a high reactive-power ferroelectric fast reactive tuner

We present a novel design of a ferroelectric fast reactive tuner (FE-FRT) capable of modulating mega-VAR reactive power on a submicrosecond timescale. The high reactive power capability of our design extends the range of applications of reactive tuners to numerous applications. We present a detailed analytical model of the performance of a megawatt-class reactive power device and benchmark it against finite-element method eigenmode and frequency domain electromagnetic simulations. We introduce new features, including an annulus design for the ferroelectric capacitors and capacitive window coupling to the cavity. We consider thermal design issues and nonlinear effects in the ferroelectric. The model covers several configurations, allowing control of the frequency of superconducting and normal-conducting cavities in a variety of applications and frequencies. We calculate that the FE-FRT designed should be capable of handling around 0.45 MVAR of reactive power with around 3 kW of resistive losses, providing a frequency tuning range of 8 kHz in an example of 400 MHz cavity geometry. Published by the American Physical Society 2024

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Conceptual Design of a Pumped Water Capsule for TREAT

This study performed mechanical design, thermal hydraulic, and fuel performance investigations to determine whether an existing large water capsule design could be modified to create forced convection boundary conditions on nuclear fuel specimens in the Transient Reactor Test facility. This concept was found to be viable and offers several advantages compared to a static water environment for a variety of transient power shape categories. The pumped capsule is not foreseen to be superior to a past concept for a larger water loop, but the pumped capsule approach is recommended for further engineering and deployment based on its high cost-to-value ratio primarily as a stop gap capability until a larger water loop can be realized.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS1973

Performance of a modified downstream-cathode MPD thruster.

Discussion of the improvements incorporated since 1969 in a low-power MPD thruster design which is considered a potential candidate for satellite station keeping and attitude control. The improvements include a new cathode design, and changes in thruster geometry, with xenon used as the propellant. A better thermal design is found to be necessary for further improvement of the thruster.

Burkhart, J. A.↗