Search NASA⌕ Search

SEARCH · Search NASA

Results for “TRANSPIRATION COOLING”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8

Small gas turbine combustor experimental study: Compliant metal/ceramic liner and performance evaluation

Combustor research relating to the development of fuel efficient small gas turbine engines capable of meeting future commercial and military aviation needs is currently underway at NASA Lewis. As part of this combustor research, a basic reverse-flow combustor has been used to investigate advanced liner wall cooling techniques. Liner temperature, performance, and exhaust emissions of the experimental combustor utilizing compliant metal/ceramic liners were determined and compared with three previously reported combustors that featured: (1) splash film-cooled liner walls; (2) transpiration cooled liner walls; and (3) counter-flow film cooled panels.

Acosta, W. A.↗

Small gas turbine combustor experimental study - Compliant metal/ceramic liner and performance evaluation

Combustor research relating to the development of fuel efficient small gas turbine engines capable of meeting future commercial and military aviation needs is currently underway at NASA Lewis. As part of this combustor research, a basic reverse-flow combustor has been used to investigate advanced liner wall cooling techniques. Liner temperature, performance, and exhaust emissions of the experimental combustor utilizing compliant metal/ceramic liners were determined and compared with three previously reported combustors that featured: (1)splash film-cooled liner walls; (2) transpiration cooled liner walls; and (3) counter-flow film cooled panels.

Acosta, W. A.↗

Experimental investigation of aerodynamic performance of cooled turbine vanes at gas- to collant-temperature ratios up to 2.75

The results of an experimental investigation of the aerodynamic performance of two geometrically similar turbine vanes with different cooling designs are presented. The test vanes were a convection-film-cooled vanes and a transpiration-cooled vane. A solid uncooled vane with the same aerodynamic profile as the cooled vane was also tested. Four vanes of each type were tested in an annular sector cascade. The cooled vanes were tested at primary to coolant temperature ratios of 1.0, 1.75, and 2.75 and a coolant to primary pressure ratios of 1.0, 1.2, and 1.5. This resulted in coolant flows up to about 10 percent of the primary flow. The principal measurements were surveys of vane exit total pressure, total temperature, and static pressure. The report includes a brief description of the test facility and the design of the test vanes. The test results presented include weight flow and efficiency data for the uncooled vanes and coolant flow, primary flow, and efficiency data as functions of the cooling variables for the cooled vanes.

Stabe, R. G.↗

Advanced oxide dispersion strengthened sheet alloys for improved combustor durability

Burner design modifications that will take advantage of the improved creep and cyclic oxidation resistance of oxide dispersion strengthened (ODS) alloys while accommodating the reduced fatigue properties of these materials were evaluated based on preliminary analysis and life predictions, on construction and repair feasibility, and on maintenance and direct operating costs. Two designs - the film cooled, segmented louver and the transpiration cooled, segmented twin Wall - were selected for low cycle fatigue (LCF) component testing. Detailed thermal and structural analysis of these designs established the strain range and temprature at critical locations resulting in predicted lives of 10,000 cycles for MA 956 alloy. The ODs alloys, MA 956 and HDA 8077, demonstrated a 167 C (300 F) temperature advantage over Hastelloy X alloy in creep strength and oxidation resistance. The MA 956 alloy was selected for mechanical property and component test evaluations. The MA 956 alloy was superior to Hastelloy X in LCF component testing of the film cooled, segmented louver design.

Henricks, R. J.↗

Liquid Oxygen/Liquid Methane Component Technology Development at MSFC

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. Besides existing in-house risk reduction activities, NASA has solicited from industry their participation on component technologies based on the potential application to the lunar ascent main engine (AME). Contracted and NASA efforts have ranged from valve technologies to engine system testbeds. The application for the AME is anticipated to be an expendable, pressure-fed engine for ascent from the moon at completion of its lunar stay. Additionally, the hardware is expected to provide an abort capability prior to landing, in the event that descent systems malfunction. For the past 4 years, MSFC has been working with the Glenn Research Center and the Johnson Space Center on methane technology development. This paper will focus on efforts specific to MSFC in pursuing ignition, injector performance, chamber material assessments and cryogenic valve technologies. Ignition studies have examined characteristics for torch, spark and microwave systems. Injector testing has yielded insight into combustion performance for shear, swirl and impinging type injectors. The majority of chamber testing has been conducted with ablative and radiatively cooled chambers with planned activities for regenerative and transpiration cooled chambers. Lastly, an effort is underway to examine the long duration exposure issues of cryogenic valve internal components. The paper will summarize the status of these efforts.

Robinson, Joel W.↗

Experimental investigation of the heat-transfer characteristics of an air-cooled sintered porous turbine blade

The results of a heat-transfer investigation on a transpiration-cooled turbine blade are presented. The investigation was made on a static cascade.506::Declassified December 11, 1953. Blade-peripheral wall-temperature distributions were measured and compared with the temperature distribution on a convection-cooled blade. A correlation of the blade-wall temperatures obtained at various gas temperatures and gas weight flows was made on the basis of a temperature-difference ratio. Blade-wall temperatures calculated using an approximate theory for turbulent flow are compared with the measured blade-wall tempeartures.

Schafer, Louis J , Jr↗

Effect of storable propellants on single-stage earth-to-orbit vehicles

A comparison is made between the storable-propellant engine and an equivalent dual-expander engine using oxygen, propane, and hydrogen propellants. The propane and hydrogen dual-expander engine is then compared with previous results with separate propane and hydrocarbon engines. It is shown that the dual-expander reduces vehicle dry mass from 94 to 89 Mg, or 5%. The hydrogen-only thrust of the dual-expander is 0.4 MN, while the separate hydrogen engines have a thrust of 2.3 MN. The low thrust level increases the difficulty of cooling the dual-expander engine, and additional hydrogen flow is added for transpirational cooling. This additional hydrogen flow leads to an increase in the hydrogen tank size. It is also shown that storable propellants increase the dry mass of single-stage earth-to-orbit vehicles by about 20% and the gross mass by about 54%. It is concluded that dual-expander engines should be studied with several thrust splits and thrust levels.

Martin, J. A.↗

Hypersonic engine component experiments in high heat flux, supersonic flow environment

A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding the sustained high thermal loads expected during hypersonic flight. Even though progress has been made in the computational understanding of fluid dynamics and the physics/chemistry of high speed flight, there is also a need for experimental facilities capable of providing a high heat flux environment for testing component concepts and verifying/calibrating these analyses. A hydrogen/oxygen rocket engine heat source was developed at the NASA Lewis Research Center as one element in a series of facilities at national laboratories designed to fulfill this need. This 'Hot Gas Facility' is capable of providing heat fluxes up to 450 w/sq cm on flat surfaces and up to 5,000 w/sq cm at the leading edge stagnation point of a strut in a supersonic flow stream. Gas temperatures up to 3050 K can also be attained. Two recent experimental programs conducted in this facility are discussed. The objective of the first experiment is to evaluate the erosion and oxidation characteristics of a coating on a cowl leading edge (or strut leading edge) in a supersonic, high heat flux environment. Macrophotographic data from a coated leading edge model show progressive degradation over several thermal cycles at aerothermal conditions representative of high Mach number flight. The objective of the second experiment is to assess the capability of cooling a porous surface exposed to a high temperature, high velocity flow environment and to provide a heat transfer data base for a design procedure. Experimental results from transpiration cooled surfaces in a supersonic flow environment are presented.

Gladden, Herbert J.↗

Cooled-turbine aerodynamic performance prediction from reduced primary to coolant total-temperature-ratio results

The prediction of the cooled aerodynamic performance, for both stators and turbines, at actual primary to coolant inlet total temperature ratios from the results obtained at a reduced total temperature ratio is described. Theoretical and available experimental results were compared for convection film and transpiration cooled stator vanes and for a film cooled, single stage core turbine. For these tests the total temperature ratio varied from near 1.0 to about 2.7. The agreement between the theoretical and the experimental results was, in general, reasonable.

Goldman, L. J.↗

Investigation of light hydrocarbon fuels with flox mixtures as liquid rocket propellants final report, 30 jun. 1964 - 30 jun. 1965

An analysis was completed for determination of the most promising hydrocarbon fuels for use with flox in upper stage rocket engines. Experimental rocket firings in uncooled, transpiration cooled, and regeneratively cooled thrust chambers were conducted using flox with methane, propane, butene-1, and a eutectic blend of pentane and isopentane. Experimental heated tube heat transfer and hypergolicity tests were conducted, and laboratory determinations of physical properties of various blends of hydrocarbon compounds were made.

HYDROCARBON FUEL↗

New type pressure transducer for severe thermal environments

Pressure transducer used in a rocket motor chamber to measure the amplitudes and frequencies of dynamic pressures /exceeding 2000 psi/ occurring during unstable combustion. the transducer utilizes a transpirational cooled porous beryllium plug and pressure transmitting column.

Source record↗

Oxidation-resistant silicide coating applied to columbium alloy screen

Coated screens withstand temperature cycling in special transpiration-cooling systems and provide porous surface that is effective at temperatures well above those limiting superalloy screen efficiency. Thickness of coating depends on time, temperature and activator concentration. Coatings are uniform and resistant to thermal cycling.

Torgerson, R. T.↗

A progress report - Induction plasma simulation of the GCNR.

Significant progress has been made in the design, construction and operation of induction coupled devices which simulate the open cycle Gas Core Nuclear Rocket. These devices incorporate solid feed of the plasma forming material (uranium and uranium simulating materials), permeable walls, seeding of the propellant, and transpiration cooled, choked flow nozzles. Operating parameters and performance data of devices employing these design features are discussed. A uranium plasma experiment is included. In addition, operating data of several devices which compare theoretical and actual performance at a variety of powers, pressures, frequencies, and sizes are discussed.

Vogel, C. E.↗