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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 631 records · Page 35

An experimental investigation with artificial sunlight of a solar hot-water heater

Thermal performance measurements were made of a commercial solar hot-water heater in a solar simulator. The objective of the test was to determine basic performance characteristics of a traditional type of flat-plate collector, with and without side reflectors (to increase the solar flux). Due to the fact that collector testing in the solar simulator permits control of the variables that affect collector performance, it was possible to obtain information on each of the following: (1) the effect of flow and incidence angle on the efficiency of a flat-plate collector (but only without side reflectors), (2) transient performance under flow and nonflow conditions, (3) the effectiveness of reflectors in increasing collector efficiency for a zero radiation angle at fluid temperatures required for solar air conditioning, and (4) the limits of applicability of a collector efficiency correlation based on the Hottel-Whillier equation (1958).

Simon, F. F.↗

Flat-plate liquid solar collector

Report presents test procedures and results of program to obtain thermal performance data on liquid, incident-angle-modifier, heat-loss-coefficient, and stagnation tests.

Shih, K.↗

Indoor and outdoor tests of a liquid solar collector

Two reports describe thermal-performance data obtained on double-covered liquid solar collector. One report describes data obtained during outdoor testing and the other describes indoor test data obtained by using Marshall Space Flight Center solar simulator. Indoor data were taken to verify performance of solar simulator.

Losey, R.↗

Indoor tests of a hot-air solar collector

Data taken relating indoor testing using solar simulator at Marshall Space Center has been compared with data taken during outdoor tests in previous studies. Data includes tests on thermal performance, time constance, and incidence-angle modifier tests in table/graph form.

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Outdoor tests of a liquid solar collector

Results of outdoor test program evaluating thermal performance of liquid solar collector are presented in report. Test article used is flatplate collector with antifreeze solution as working fluid.

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Verification test of the MSFC solar simulator using a Honeywell double-covered liquid solar collector

Additional verification data to support the utilization of the MSFC Solar Simulator for testing solar collectors was obtained. The Honeywell double-covered liquid solar collector number 2 for which thermal performance data under natural outdoor conditions had been previously obtained was installed on the Solar Simulator and subjected to a series of eight tests under various conditions of wind flow rate. Although these test conditions were not absolutely identical to those of the outdoor tests, they are considered to be sufficiently representative to provide a basis for an accurate comparative analysis of the data recorded for both test programs.

Shih, K., Sr.↗

Experimental evaluation of a fixed collector employing vee-trough concentrator and vacuum tube receivers

A test bed for experimental evaluation of a fixed solar collector which combines an evacuated glass tube solar receiver with a flat plate/black chrome plated copper absorber and an asymmetric vee-trough concentrator was designed and constructed. Earlier predictions of thermal performance were compared with test data acquired for a bare vacuum tube receiver; and receiver tubes with Alzak aluminum, aluminized FEP Teflon film laminated sheet metal and second surface ordinary mirror reflectors. Test results and system economics as well as objectives of an ongoing program to obtain long-term performance data are discussed.

Selcuk, M. K.↗

Cryogenic foam insulation for LH2 fueled subsonic transports

Shortages of petroleum-based aircraft fuels are foreseen before the end of the century. To cope with such shortages, NASA is developing a commercial aircraft which can operate on liquid hydrogen. Various foam insulators for LH2 storage are considered in terms of thermal performance and service life. Of the cryogenic foams considered (plain foam, foam with flame retardants and fiberglass reinforcement, and foam with vapor barriers), polyurethane foams were found to be the best. Tests consisted of heating a 5 cm layer of insulation around an aluminum tank containing LH2 to 316 K, and then cooling it to 266 K, while the inner surface was maintained at LH2 temperature (20 K).

Sharpe, E. L.↗

Weathering of a liquid-filled solar collector

Report describes procedures and results of tests for effects of weathering on flat-plate liquid solar collector. Thermal performance was measured before and after natural weathering for 15-1/2 months by using Marshall Space Flight solar simulator.

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Fin-tube solar collectors

Report presents test procedures and results of thermal-performance evaluation of seven commercial fin tube (liquid) solar collector-absorber plates. Tests were conducted indoors at Marshall Space Flight Center Solar simulator. Results are graphically shown along with supporting test data and summary, indicating efficiency as function of collector inlet temperature.

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Testing of a solar collector with concentrating mirrors

Commerical flat-plate solar collector with concentrating mirrors has been tested for thermal performance, structured behavior under static load, and effects of long-term natural weathering. Report documents results of testing and concludes that absorptivity was degraded by weathering.

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Design data brochure for the Owens-Illinois Sunpak (TM) air-cooled solar collector

Information necessary to evaluate the design and installation of the Owens-Illinois Sunpak TM Air-Cooled Solar Collector is presented. Information includes collector features, fluid flow, thermal performance, installation and system tips. The collector utilizes a highly selective wavelength coating in combination with vacuum insulation, which virtually eliminates conduction and convention losses.

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Evaluation of SHABERTH: A bearing simulation computer program

To investigate lubrication effects on bearing thermal performance, an investigation was performed to determine the feasibility of using the SKF program SHABERTH for simulating the performance of cryogenically lubricated ball bearings. As a part of this study, the particular application chosen for SHABERTH was to simulate the performance of the Space Shuttle main engine turbo-pump and pre-burner bearing system.

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A graphical approach to the efficiency of flat-plate collectors

A nomogram is described which can be used to determine the thermal performance of flat plate solar collectors, resulting in two performance factors: the net absorptance and the net heat loss coefficient. The nomogram takes into account angle of incidence, collector slope, absorber plate design, insulating materials, thicknesses, optical properties of absorbing surfaces and glazing materials, and flow factors. A case example is given to illustrate the use of the nomogram.

Selcuk, M. K.↗

Evaluation of an evacuated-tube liquid solar collector

Indoor and outdoor thermal performances of collectors are compared in report. Tests conducted on indoor solar simulator with data from both diffuse and specular reflectors are presented graphically and in tables. Comparisons with previous data for prototype show effects of improved mainfold.

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Thermal energy storage testing facility

The thermal performance of resistance storage heaters in respect to current standards is determined. The design and construction of a storage heater test facility with capability for measuring the performance of electric resistance heated storage units is described. The performance of commercial units are compared based on existing standards. Additional performance standards are proposed.

Schoenhals, R. J.↗

Heater Composite Measures Heat Transfer

Composite consisting of commercially available elements has been developed to measure heat transfer. Composite provides a simple, convenient, low-cost device for use in heat-transfer work for rapid evaluation of thermal performance of both flat and simply curved objects. Device utilizes available off-the-shelf materials and provides a convenient method, with good resolution of local temperatures and heat transfer, with measurement accuracy at near-normal room conditions.

Hippensteele, S. A.↗

Temperature control simulation for a microwave transmitter cooling system

The thermal performance of a temperature control system for the antenna microwave transmitter (klystron tube) of the Deep Space Network antenna tracking system is discussed. In particular the mathematical model is presented along with the details of a computer program which is written for the system simulation and the performance parameterization. Analytical expressions are presented.

Yung, C. S.↗