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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 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Evaluation of initial collector field performance at the Langley Solar Building Test Facility

The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. A 1,180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row were calculated and recorded along with sensor, insolation, and weather data every five minutes using a minicomputer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

Boyle, R. J.↗
NASA NTRS1977

Evaluation of initial collector field performance at the Langley Solar Building Test Facility

The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. An 1180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row are calculated and recorded along with sensor, insolation, and weather data every 5 minutes using a mini-computer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

Boyle, R. J.↗
NASA NTRS1979

Performance evaluation of a liquid solar collector

Report describes thermal performance and structural-load tests on commercial single glazed flat-plate solar collector with gross area of 63.5 sq ft that uses water as heat-transfer medium. Report documents test instrumentation and procedures and presents data as tables and graphs. Results are analyzed by standard data-reduction methods.

Source record↗
NASA NTRS2011

Thermally Stabilized Transmit/Receive Modules

RF-hybrid technologies enable smaller packaging and mass reduction in radar instruments, especially for subsystems with dense electronics, such as electronically steered arrays. We are designing thermally stabilized RF-hybrid T/R modules using new materials for improved thermal performance of electronics. We are combining advanced substrate and housing materials with a thermal reservoir material, and develop new packaging techniques to significantly improve thermal-cycling reliability and performance stability over temperature.

thermal cycling stress↗
NASA NTRS1977

Thermodynamic data report for the Titan/Centaur TC-5 extended mission

The Titan/Centaur vehicle, with the Helios B spacecraft, was launched on January 15, 1976. After the spacecraft was placed into its desired heliocentric trajectory, the Centaur vehicle continued into an extended mission to perform experiments demonstrating increased operational capabilities. The thermal performance of all pertinent Centaur systems and components was evaluated and its capability for satisfactory operation for long duration space coasts was verified. The selected thermal control techniques maintained the Centaur component temperatures within their qualification limits for the entire 8-hour and 22-minute duration of the extended mission.

Lacovic, R. F.↗
NASA NTRS1991

Thermal control surfaces experiment flight system performance

The Thermal Control Surfaces Experiment (TCSE) is the most complex system, other than the LDEF, retrieved after long term space exposure. The TCSE is a microcosm of complex electro-optical payloads being developed and flow by NASA and the DoD including SDI. The objective of TCSE was to determine the effects of the near-Earth orbital environment and the LDEF induced environment on spacecraft thermal control surfaces. The TCSE was a comprehensive experiment that combined in-space measurements with extensive post flight analyses of thermal control surfaces to determine the effects of exposure to the low earth orbit space environment. The TCSE was the first space experiment to measure the optical properties of thermal control surfaces the way they are routinely measured in a lab. The performance of the TCSE confirms that low cost, complex experiment packages can be developed that perform well in space.

Wilkes, Donald R.↗
NASA NTRS1992

Thermal control surfaces experiment flight system performance

The Thermal Control Surfaces Experiment (TCSE) is the most complex system retrieved after long term space exposure. The TCSE is a microcosm of complex electro-optical payloads being developed and flown. The objective of the TCSE on the LDEF was to determine the effects of the near-Earth orbital environment and the LDEF induced environment on spacecraft thermal control surfaces. The TCSE was a comprehensive experiment that combined in-space measurements with extensive post-flight analyses of thermal control surfaces to determine the effects of exposure to the low Earth orbit space environment. The TCSE was the first space experiment to measure the optical properties of thermal control surfaces the way they are routinely measured in the lab. The performance of the TCSE flight system on the LDEF was excellent.

Wilkes, Donald R.↗
NASA NTRS1973

Ion thruster thermal characteristics and performance.

Experimental and analytical results for a typical 20-cm-diam, hollow-cathode ion thrustor are reported. The foundation of the investigation was the application of thermal model correction techniques. Pertinent thermal properties and plasma heating characteristics of the thrustor were determined through correlation and integration of temperature measurement data with a single-state Wiener-Kalman filter. The thrustor self-heating levels on various parts were realistically estimated. Analytically predicted temperatures were forced to agree with the measured values for the purpose of constructing a corrected thermal model, which could then be used to evaluate more realistic thrustor circumstances and environments. The expected accuracy of the resultant analytical network model was demonstrated to be plus or minus 10 K. Thrustor thermal performance data for a typical five-thrustor array are presented as functions of environmental solar intensities. The thermal analyses are also extended to a 30-cm thrustor system.

Wen, L.↗
NASA NTRS1972

Modular thermal analyzer routine, volume 1

The Modular Thermal Analyzer Routine (MOTAR) is a general thermal analysis routine with strong capabilities for performing thermal analysis of systems containing flowing fluids, fluid system controls (valves, heat exchangers, etc.), life support systems, and thermal radiation situations. Its modular organization permits the analysis of a very wide range of thermal problems for simple problems containing a few conduction nodes to those containing complicated flow and radiation analysis with each problem type being analyzed with peak computational efficiency and maximum ease of use. The organization and programming methods applied to MOTAR achieved a high degree of computer utilization efficiency in terms of computer execution time and storage space required for a given problem. The computer time required to perform a given problem on MOTAR is approximately 40 to 50 percent that required for the currently existing widely used routines. The computer storage requirement for MOTAR is approximately 25 percent more than the most commonly used routines for the most simple problems but the data storage techniques for the more complicated options should save a considerable amount of space.

Oren, J. A.↗
NASA NTRS1981

Solar cooling system performance, Frenchman's Reef Hotel, Virgin Islands

The operational and thermal performance of a variety of solar systems are described. The Solar Cooling System was installed in a hotel at St. Thomas, U. S. Virgin Islands. The system consists of the evacuated glass tube collectors, two 2500 gallon tanks, pumps, computerized controller, a large solar optimized industrial sized lithium bromide absorption chiller, and associated plumbing. Solar heated water is pumped through the system to the designed public areas such as lobby, lounges, restaurant and hallways. Auxiliary heat is provided by steam and a heat exchanger to supplement the solar heat.

Harber, H.↗
NASA NTRS1987

Self-regulating heater application to Shuttle/Centaur hydrazine fuel line thermal control

The Shuttle/Centaur high energy upper stage vehicle thermal environments were more severe than previous Centaur vehicle thermal environments, creating need for a new hydrazine fuel line thermal control technique. Constant power heaters did not satisfy power dissipation requirements, because the power required to maintain fuel line thermal control during cold conditions exceeded the maximum power allowable during hot conditions. Therefore, a Raychem Thermolimit self-regulating heater was selected for this application, and was attached to the hydrazine fuel line with Kapton and aluminum foil tapes. Fuel line/heater thermal modeling and subsequent thermal vacuum chamber testing simulated heater thermal performance during all worst-case Shuttle/Centaur thermal environmental conditions. Fuel line temperatures were maintained between the 4C to 71C limits during all analytical and test cases. Finally, the thermal model predictions were correlated with the test data, thereby ensuring that the model would provide satisfactory predictions for future missions and/or vehicles.

Unkrich, David B.↗
NASA NTRSDate not supplied

Solar Absorptivity Degradation of Spacecraft Materials Due to UV and Charged Particles in the Gateway Environment

Traditionally, most of the data accumulated for material optical property degradation in space has been in the Low Earth Orbit (LEO) environment. However, Gateway is a new space station that will be assembled and flown in Near Rectilinear Halo Orbit (NRHO) for 15 years. Additionally, some Gateway modules will have a slow transit from Earth to NRHO that will take over a year to pass through the Van Allen Belts, which contain damaging charged particles. The environments Gateway modules will encounter are not well characterized. Environmental factors such as charged particles and ultraviolet (UV) radiation have been shown to significantly increase solar absorptivity (α) for some thermal control materials and coatings. Since α will impact thermal performance over the mission, the Gateway Passive Thermal Control System (PTCS) Group has identified charged particle and UV degradation of Gateway materials as a knowledge gap. Candidate materials and coatings were subjected to expected mission charged particle environments and over 5000 Equivalent Solar Hours (ESH) of UV at NASA Goddard Space Flight Center (GSFC). In situ change in reflectivity was observed at specified intervals during testing such that change in α could be plotted as a function of time of solar exposure.

Optical Property↗
NASA NTRS1976

Comparative performance of solar thermal power generation concepts

A performance comparison is made between the central receiver system (power tower) and a distributed system using either dishes or troughs and lines to transport fluids to the power station. These systems were analyzed at a rated capacity of 30 MW of thermal energy delivered in the form of superheated steam at 538 C (1000 F) and 68 atm (1000 psia), using consistent weather data, collector surface waviness, pointing error, and electric conversion efficiency. The comparisons include technical considerations for component requirements, land utilization, and annual thermal energy collection rates. The relative merits of different representative systems are dependent upon the overall conversion as expressed in the form of performance factors in this paper. These factors are essentially indices of the relative performance effectiveness for different concepts based upon unit collector area. These performance factors enable further economic tradeoff studies of systems to be made by comparing them with projected production costs for these systems.

Wen, L.↗
NASA NTRS1995

Test-Derived Effective Emittance for Cassini MLI Blankets and Heat Loss Characteristics in the Vicinity of Seams

Thermal performance of Cassini MLI blankets was characterized in thermal vacuum tests. Effective emittance was derived for the standard and high-temperature layups, with or without micrometeoroid protection standoffs, and for a high-performance duo-layup with staggered seams. The all-Kapton layup wa shown to have a 19% higher effective emittance than the hybrid Kapton-Mylar layup, and the duo-layup exhibited a dramatic capability of reducing heat dissipation by 2.6 fold. Several different definitions of effective emittance are discussed, and their relations to distinct hardware-MLI configurations and corresponding modeling techniques clarified. Large temperature differences (up to 70 C) were observed between the center and seam of a blanket. Heat losses in the vicinity of seams are qualified, and a major MLI heat loss mechanism elucidated.

Cassini↗
NASA NTRS1975

Application of the CINGEN program a thermal network data generator

The application of the CINGEN computer program and two of its supporting programs for the evaluation of structural and thermal performance of physical systems was described. The CINGEN program was written and implemented to avoid the duplication effort of performing a finite element approach for structural analysis and a finite differencing technique for thermal analysis, as well as the desire for a geometrical representation of the thermal model to reduce modeling errors. The program simplifies the thermal modeling process by performing all of the capacitance and conductance calculations normally done by the analyst. Each solid element is divided into five tetrahedrons, allowing the total volume to be calculated precisely. A sample problem was illustrated.

Shultz, W. E.↗
NASA NTRS1992

Spacelab carrier complement thermal design and performance

The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

Bancroft, S.↗
NASA NTRS1980

Solar energy system performance evaluation: Seasonal report for SEMCO, Loxahatchee, Florida

The operational and thermal performance of a variety of solar systems installed in operational test sites are described. The analysis used is based on instrumented system data monitored and collected for at least one full season of operation. The long-term field performance of the installed system and the technical contributions to the definition of techniques and requirements solar energy system design are analyzed. The solar energy system was designed to supply domestic hot water for a family of four, single-family residences. It consists of two liquid flat plate collectors, single tank, controls, and transport lines.

Source record↗
NASA NTRS1980

Solar energy system performance evaluation: Seasonal report for fern, Tunkhannock, Pennsylvania

The operational and thermal performance of a variety of solar systems installed in operational test sites are described. The analysis is based on instrumented system data monitored and collected for at least one full season of operation. The long-term field performance of the installed system is reported, and technical contributions to the definition of techniques and requirements for solar energy system design are made. The solar energy system was designed to supply space heating and domestic hot water for single-family residences. The system consists of air flat plate collectors, storage tank, pumps, heat exchangers, associated plumbing, and controls.

Source record↗