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Results for “thermal protection materials”

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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Technology Readiness Assessment for HEEET TPS

The HEEET project was conceived to develop a heatshield with a high performance ablative thermal protection material that can withstand the extreme entry environment produced as a result of rapid deceleration during high speed entry into Venus, Saturn, Uranus or higher speed entry into Earth's atmosphere. Successful maturation of HEEET supports future New Frontiers and Discovery AO's, as well as Flagship and directed missions in the longer term. In addition, HEEET has the potential to evolve and to support re-entry to Earth, for missions such as Mars Sample Return.The primary goal of the HEEET Project was to develop an ablative TPS heat-shield based on woven TPS technology to Technology Readiness Level (TRL) 6. Key evidence to support the TRL evaluation includes: Demonstration of reproducible manufacturing of a dual layer material over a range of thicknesses and integrated on to a heatshield engineering test unit at a scale that is applicable to near term Discovery as the highest priority and future NF missions as secondary priority set of missions. Demonstration of predictable and stable performance of the dual layer TPS over a range of entry environments that are applicable to near term Discovery and NF missions of interest to SMD.Includes completion of coupon arc jet and laser testing and development of a mid-fidelity thermal response model that correlates with test results. Demonstration of flight heatshield system design for a range of sizes and loads that are relevant to near term Discovery and NF missions of interest to SMD. Includes completion of structural testing to validate analytic thermal/structural models and development of a material property database. Includes structural testing of a ~1m Engineering Test Unit under relevant entry loads.

Gage, Peter↗
DOE OSTI2023

Doped Lanthanum Chromite-refractory Based Composites Sensors for High Temperature Monitoring in Harsh Environments Systems

In order to test and monitor the operational stability and conditions of various energy, and manufacturing systems and their components, development of accurate sensors capable of operating at temperatures in excess of 1000 °C in various environments for long durations is required. In addition, many of these harsh-environment systems do not permit sensors to be directly inserted, so these sensors need to be embedded into thermal protective materials. In this work were developed high-temperature embedded thermocouples composed of various doped lanthanum chromites-refractory based composites synthesized by a mixed-oxide route and directly embedded into a Al2O3 based refractory. The electrical properties were specifically manipulated by altering the level of percolation of the conductive phase within the refractory constituent. Chemical stability of sensors was determined by phase development analysis by X-ray diffraction and X-ray photoelectron spectroscopy; Seebeck coefficients were determined by thermoelectric voltages measurements at temperature up to 1400 oC.

Perovskite LaCrO3, High-temperature conductivity, ↗
NASA NTRS1975

A users manual for a revised version of the Langley charring ablator program

A computer program is described that will compute the transient response of a thermal protection material to a prescribed heat input at the surface. The program has the capability of analyzing pyrolysis gas chemical kinetics in detail and treating pyrolysis reactions-in-depth. Deposition of solid products produced by chemical reactions in the gas phase is included in the analysis. An outline is given for the theory. detailed operating instructions for the computer program are included.

Stroud, C. W.↗
NASA NTRS1976

Measurements of spectral and total emittance of reinforced carbon-carbon

Elevated temperature measurements of the spectral emittance of reinforced carbon-carbon (RCC) as the thermal protection material for the leading edge areas of the Space Shuttle Orbiter were carried out in situ, with environments provided by arc-heated streams of air and argon. A monochromator, infrared pyrometers, and thermocouples were used in evaluating the response of the RCC test specimens during the emittance measurements. Results indicate that the material is nongray, with lowest spectral emittance at the short wavelengths and with relatively high total emittance. The trend of the total emittance data suggests a slight decrease in total emittance with increasing temperature, although the emittance value stabilizes with continuing exposure.

Grinberg, I. M.↗
NASA NTRS1976

Molecular outgassing measurements for an element of the Shuttle thermal protection system

Molecular outgassing studies were conducted on a thermal-protection material recently developed for the Shuttle Orbiter. Molecular outgassing rates as low as 10 to the minus 11th g/sq cm/sec, condensation coefficients, and molecular desorption rates were measured in four separate experiments using cryogenically and thermoelectrically cooled quartz crystal microbalances. Although the initial outgassing rates are high, they decreased to values in the 10 to the minus 10th g/sq cm/sec range in a reasonable period of time. Outgassing rates do not increase after entry heating although the condensation coefficients at various microbalance collection-surface temperatures become somewhat larger.

Visentine, J. T.↗
NASA NTRS1982

Catalytic recombination and Space Shuttle heating

The measurement of surface temperatures on the thermal protection materials of the Space Shuttle Orbiter during reentry provides the basis for an important test of the prediction techniques developed over the past 10 years for reacting flows over reentry vehicles. The present investigation is concerned with comparisons of calculated temperatures with those measured during the second and third Space Shuttle missions. The general trends of the calculations compared favorably with the measurements. However, the calculations overpredicted the temperatures on the forward part of the windward centerline. Agreement was better farther aft, especially at the later times in the entry. The investigation has pointed out the significance of surface chemical reactions on the heat flux to the surface of the Orbiter and the need for further understanding.

Scott, C. D.↗
NASA NTRS1983

A review of nonequilibrium effects and surface catalysis on shuttle heating

A review is given of the nonequilibrium calculation techniques by various authors over the past decade to predict heat fluxes to the windward side of the Space Shuttle orbiter. The results of these techniques are compared with measurements made on the first few flights of the Space Shuttle. The calculations attempt to account for finite rate chemistry in the shock layer around the vehicle and for finite rate catalytic atom recombination on the thermal protection materials. The techniques considered are the axisymmetric viscous shock layer method, three dimensional reacting Euler equation solutions coupled with axisymmetric analog boundary layer method, and a recently developed nonequilibrium 3-D viscous shock layer method.

Scott, C. D.↗
NASA NTRS1987

Computer Simulation of Ablator Charring

Transient response of thermal-protection material to heat applied to surface calculated using CHAP III computer program. Used to analyze chemical kinetics of pyrolysis gas in detail and examine pyrolysis reactions-in-depth. Analysis includes deposition of solid products produced by chemical reactions in gas phase. Uses modeling technique that approximates wide range of ablation problems. CHAP III written in FORTRAN IV.

Stroud, C. W.↗
NASA NTRS1988

Heating Distributions For Aeroassisted Vehicles

Report discusses anticipated distributions of temperature on symmetric and asymmetric large-angle blunt nose-cone space vehicles re-entering atmosphere. Report considers three cone angles; 100 degree, 120 degree, and 140 degree. Experimental surface-temperature data obtained on specimens made of thermal-protection materials proposed for vehicles. Discusses relationship between stagnation-point heat-transfer rate and bow-shock standoff distance for cones.

Stewart, David A.↗
NASA NTRS1988

In-flight rain damage tests of the shuttle thermal protection system

NASA conducted in-flight rain damage tests of the Shuttle thermal protection system (TPS). Most of the tests were conducted on an F-104 aircraft at the Dryden Flight Research Facility of NASA's Ames Research Center, although some tests were conducted by NOAA on a WP-3D aircraft off the eastern coast of southern Florida. The TPS components tested included LI900 and LI2200 tiles, advanced flexible reusable surface insulation, reinforced carbon-carbon, and an advanced tufi tile. The objective of the test was to define the damage threshold of various thermal protection materials during flight through rain. The test hardware, test technique, and results from both F-104 and WP-3D aircraft are described. Results have shown that damage can occur to the Shuttle TPS during flight in rain.

Meyer, Robert R., Jr.↗
NASA NTRS2012

Body weight of advanced concept hypersonic aircraft

In this paper, preliminary qualitative and quantitative comparisons of the body weight of five hypersonic aircraft configurations are conducted. The five configurations are briefly described as follows: (1) a wing-and-body arrangement with a power-law, circular cross-section body and a delta wing; (2) an all-body vehicle with delta planform and elliptical cross-sections; (3) a wingless wave rider configuration; (4) a winged wave rider configuration; and (5) the spacewing concept, an oblique flying wing at low speed that yaws to 90 deg sweep and flies end-on at hypersonic speeds. The vehicles are defined by their external moldline geometries and by the interior arrangement of their fuel tanks and other components. Intersecting, circular-lobed tankage is used in vehicles with noncircular bodies. The nonusable volume of such concepts is calculated. The structural concept, structural materials, Thermal Protection System, and heat load are allowed to vary with vehicle longitudinal station. Relative strengths and weaknesses of the various hypersonic aircraft concepts in terms of body weight are summarized.

Mark D Ardema↗
NASA NTRS1992

Shuttle Infrared Leeside Temperature Sensing (SILTS) experiment - STS-35 and STS-40 preliminary results

Preliminary results from the STS-35 and STS-40 flight of the Shuttle Infrared Leeside Temperature Sensing (SILTS) experiment aboard the Shuttle Orbiter Columbia are presented. Infrared images are shown in false-color indicating the level and distribution of surface temperature over the vehicle's leeside fuselage during entry. Features evident in the imagery are related to their causative aerodynamic flow phenomena. Quantitative comparisons of the infrared image data with in situ temperature measurements obtained with thermocouples located at the aerodynamic surface of the thermal protection materials are presented.

Throckmorton, David A.↗
NASA NTRS1992

Numerical procedures for three-dimensional computational surface thermochemistry

Models and equations for surface thermochemistry and near-surface thermophysics of aerodynamically-heated thermal protection materials are reviewed, with particular emphasis on computational boundary conditions for surface mass and energy transfer. The surface energy and mass balances, coupled with an appropriate ablation or surface catalysis model, provide complete thermochemical boundary conditions for a true multidisciplinary solution of the fully coupled fluid-dynamics/solid mechanics problem. Practical approximate solutions can be obtained by using a detailed model with full thermophysics for either the solid or fluid phase amd a semianalytic method for the other half of the problem. A significant increase in the state-of-the-art in aerothermal computational fluid dynamics is possible by uniting CFD methodology with surface thermochemistry boundary conditions and the heat-balance-integral method.

Milos, Frank S.↗
NASA NTRS1992

Aerobraking technology for manned space transportation systems

The paper discusses aerobraking technology for manned missions to Mars. Special attention is given to the human and technical parameters that strongly affect the design of aerobrakes and the aerothermodynamic environment which will be encountered during atmospheric passage to Mars, and to the thermal protection technology for aerobrakes, including some recent developments in ablative thermal protection materials. Some results of tests are presented, and recommendations are made for future technology developments in aerobraking.

Arnold, J. O.↗
NASA NTRS1993

Thermal protection systems for all-weather reusable launch vehicles

The topics addressed are: (1) thermal protection system technology needs; and (2) long-term, reusable thermal protection materials, such as recently developed materials (CMC's, metallics, ceramics, etc.), which require ground and flight testing, basic materials whose properties are properties verified/quantified, and load-carrying hot structured and controlled surfaced materials.

Giegerich, Marc J.↗
NASA NTRS1994

Review of numerical procedures for computational surface thermochemistry

Models and equations for surface thermochemistry and near-surface thermophysics of aerodynamically heated thermal protection materials are reviewed, with particular emphasis on computational boundary conditions for surface mass and energy transfer. The surface energy and mass balances, coupled with an appropriate ablation or surface catalysis model, provide complete thermochemical boundary conditions for a true multidisciplinary solution of the fully coupled fluid-dynamics/solid mechanics problem. Practical approximate solutions can be obtained by using a detailed model with full thermophysics for either the solid or fluid phase and a semianalytic method for the other half of the problem. A significant increase in the state-of-the-art in aerothermal computational fluid dynamics is possible by uniting computational fluid dynamic (CFD) methodology with surface thermochemistry boundary conditions and the heat-balance-integral method.

SOLID MECHANICS↗
NASA NTRS1997

Space Shuttle Reusable Solid Rocket Motor (RSRM) Hand Cleaning Solvent Replacement at Kennedy Space Center (KSC)

At Kennedy Space Center (KSC), Thiokol Corporation provides the engineering to assemble and prepare the Space Shuttle Reusable Solid Rocket Motor (RSRM) for launch. This requires hand cleaning over 86 surfaces including metals, adhesives, rubber and electrical insulations, various painted surfaces and thermal protective materials. Due to the phase-out of certain ozone depleting chemical (ODC) solvents, all RSRM hand wipe operations being performed at KSC using l,l,1-trichloroethane (TCA) were eliminated. This presentation summarizes the approach used and the data gathered in the effort to eliminate TCA from KSC hand wipe operations.

Keen, Jill M.↗