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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Evaluation of thermal and mechanical loading effects on the structural behavior of a SIC/titanium composite

Composite specimens of titanium-15-3 matrix reinforced with continuous SCS-6 silicon carbide fibers were tested under a variety of thermal and mechanical loadings. A combined experimental/finite element approach was used to estimate the effective in situ modulus of the matrix material and to evaluate changes in modulus due to the applied loads. Several fiber orientations were tested. Results indicate that the effect of thermal loads on composite stiffness varies with fiber orientation. Applications of this method to test specimens damaged by uniaxial tension, thermal cycling, and isothermal fatigue loadings are used to illustrate that by monitoring overall structural behavior, changes in stiffness caused by thermomechanical loading can be detected.

Grady, J. E.↗
NASA NTRS1990

Evaluation of thermal and mechanical loading effects on the structural behavior of a SiC/titanium composite

Composite specimens of titanium-15-3 matrix reinforced with continuous SCS-6 silicon carbide fibers were tested under a variety of thermal and mechanical loadings. A combined experimental/finite element approach was used to estimate the effective in-situ modulus of the matrix material and to evaluate changes in modulus due to the applied loads. Several fiber orientations were tested. Results indicate that the effect of the thermal loads on composite stiffness varies with fiber orientation. Applications of this method to test specimens damaged by uniaxial tension, thermal cycling, and isothermal fatigue loadings are used to illustrate that by monitoring overall structural behavior, changes in stiffness caused by thermomechanical loading can be detected.

Grady, Joseph E.↗
NASA NTRS1978

Thermal performance evaluation of the Solargenics solar collector at outdoor conditions

Test procedures used during the performance of an evaluation program are presented. The test program was conducted to obtain the following performance data and information on the solar collector. (1) thermal performance data under outdoor conditions; (2) structural behavior of collector under static conditions; (3) effects of long term exposure to material weathering elements. The solargenics is a liquid, single-glazed, flat plate collector. Approximate dimensions of each collector are 240 inches long, 36 inches wide, and 3.5 inches in depth.

Source record↗
NASA NTRS1977

Thermal performance evaluation of Solar Energy Products Company (SEPCO) 'Soloron' collector tested outdoors

The test article, Model EF-212, Serial Nr. 002, is a single glazed collector with a nonselective absorber plate, using flowing air as the heat transfer medium. The absorber plate and box frame are aluminum and the insulation is one inch isocyanurate foam board with thermal conductivity of 0.11 (BTU/sq ft Hr0/ft.) The tests included the following. (1) time constant test, (2) collector efficiency test, (3) collector stagnation test, (4) incident angle modifier test, (5) load test, (6) weathering test, and (7) absorber plate optical properties test. The results of these tests are tabulated, graphed, or otherwise recorded.

Chiou, J., Sr.↗
NASA NTRS1985

Evaluation of thermal control surface on-orbit servicing methods for long term missions

Future activities of NASA will include the long-term (10 - 30 years) operation of space vehicles. For this reason, there will be an urgent need to provide the basic technology for space vehicle thermal control surfaces and their functional maintenance for future long-term missions. One of the problems arising in connection with such missions is related to contamination which can degrade operational design parameters of critical and thermal control surfaces. All Space Based Payloads will arrive on orbit with a certain level of contamination from ground handling, and, on orbit, will be subjected to some level of contamination over their mission life. For the extension of mission life, it appears practical to institute surface refurbishment procedures for contaminated and degraded surfaces. Potential resurfacing methods are evaluated, taking into account three potential processes. The most promising of these is a cleaning procedure based on the utilization of atomic oxygen.

Saylor, W.↗
NASA NTRS1978

Thermal performance evaluation of the Calmac (liquid) solar collector

The procedures used and the results obtained during the evaluation test program on the S. N. 1, (liquid) solar collector are presented. The flat plate collector uses water as the working fluid. The absorber plate is aluminum with plastic tubes coated with urethane black. The glazing consists of .040 in fiberglass reinforced polyester. The collector weight is 78.5 pounds with overall external dimensions of approximately 50.3in. x 98.3in. x 3.8in. The following information is given: thermal performance data under simulated conditions, structural behavior under static loading, and the effects of long term exposure to natural weathering. These tests were conducted using the MSFC Solar Simulator.

Usher, H.↗
NASA NTRS1979

Thermal performance evaluation of the Semco (liquid) solar collector

Procedures used and results obtained during the evaluation test program on a flat plate collector which uses water as the working fluid are discussed. The absorber plate is copper tube soldered to copper fin coated with flat black paint. The glazing consists of two plates of Lo-Iron glass; the insulation is polyurethane foam. The collector weight is 242.5 pounds with overall external dimensions of approximately 48.8 in. x 120.8 in. x 4.1 in. The test program was conducted to obtain thermal performance data before and after 34 days of weather exposure test.

Source record↗
NASA NTRS1985

High time service evaluation of thermal barrier coatings on the Rolls-Royce RB211 engine

One of the main concerns of airline operators for the use of thermal barrier coatings (TBC) in the turbine is that the coating will spall and cause a premature engine removal. Even though much cyclic data is available on TBCs, high time data is much harder and expensive to come by. The typical 150 h type test used to qualify hardware, or modifications, falls far short of the 5 to 10,000 hour experience desired. One way to obtain data demonstrating the longevity of TBCs is through a service evaluation program on a commercial engine. For a meaningful evaluation of the TBC system it must be applied to a component which operates in a typical hot end environment. In addition the component performance should not suffer if the coating is lost. For these reasons Rolls-Royce chose to coat the IP turbine nozzle guide vanes, and run these in an RB211 engine. Two ceramic top coats and several different bond coats were tested in a rainbow fashion on several engines. Three layer magnesium zirconate was used as a base line. Various yttria stabilized zirconia ceramics were used. Top MCrAlY bond coats were applied by various techniques. Some of the coated vanes have now accumulated ofer 5000 hours. The results are presented from the first sets with 2500 and 4200 hours of service respectively.

Toriz, F. Chris↗
NASA NTRS1980

Thermal performance evaluation of the Suncatcher SH-11 (liquid) solar collector

The procedures used and the results obtained during the evaluation test program on the Solar Unlimited, Inc., Suncatcher SH-11 (liquid) solar collector are presented. The flat-plate collector case assembly is made of .08 inch aluminum 3003 H14 riveted with fiberglass board insulation. The absorber consists of collared aluminum fins mechanically bonded to 3/8 inch copper tubing and coated with 3M Nextel black. Water is used as the working fluid. The glazing is made of a single glass, 1/8 inch water white, tempered and antireflective. The collector weight is 85 pounds with overall external dimensions of about 35.4 in x 82.0 in x 4.0 in. Thermal performance data on the Solar Unlimited Suncatcher SH-11 solar collector under simulated conditions were conducted using the MSFC Solar Simulator.

Source record↗
NASA NTRS1990

Evaluation of thermal loading on a methane injector at high pressure and temperature

Experimental and numerical analyses are conducted to determine the surface temperature on a methane fuel injector used to produce a high enthalpy test stream for a combustion-fed subscale wind tunnel facility. It was found that the ratio of the methane fuel injection velocity to the air stream velocity is a significant factor in the production of high injector surface temperatures which lead to rapid deterioration of the fuel injector structure. The numerical code utilized for the computational analysis was found to be representative of the experimentally measured data since the experimental trends were reproduced by the numerical simulation. The quantitative accuracy of the numerical predictions could not be assessed from the data gathered because of the difficulty of making a noninterfering injector surface temperature measurement. The numerical code can be used for parametric evaluation of combustor parameters and thus will serve as an important tool in the design of such fuel injector systems.

Harvin, Stephen F.↗