Calorimetric study of the thermodynamic properties of the nickel-cadmium cell Final report, 1 Oct. 1964 - 31 Dec. 1965
Thermal properties of electrochemical cells from calorimetry of nickel-cadmium battery
ELECTROCHEMICAL CELL↗
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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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Multiscale Modeling of Carbon/Phenolic Composite Thermal Protection Materials: Atomistic to Effective Properties
Next generation ablative thermal protection systems are expected to consist of 3D woven composite architectures. It is well known that composites can be tailored to achieve desired mechanical and thermal properties in various directions and thus can be made fit-for-purpose if the proper combination of constituent materials and microstructures can be realized. In the present work, the first, multiscale, atomistically-informed, computational analysis of mechanical and thermal properties of a present day - Carbon/Phenolic composite Thermal Protection System (TPS) material is conducted. Model results are compared to measured in-plane and out-of-plane mechanical and thermal properties to validate the computational approach. Results indicate that given sufficient microstructural fidelity, along with lowerscale, constituent properties derived from molecular dynamics simulations, accurate composite level (effective) thermo-elastic properties can be obtained. This suggests that next generation TPS properties can be accurately estimated via atomistically informed multiscale analysis.
Materials Science↗
Thermal Conductivity Estimation from Transient Test Data with Embedded Thermocouples using Genetic Algorithm Optimization
Inverse heat transfer methodology previously developed to estimate thermal properties of high temperature fibrous insulation from embedded thermocouples was applied to the thermoplastic polymer, polyether-ether-ketone (PEEK). A small experimental setup was utilized to test the PEEK sample between temperatures of 300 K and 525 K at atmospheric pressure. Cylindrical plugs of PEEK with three thermocouples embedded at various depths were incorporated in the test sample. The experimental PEEK thermocouple data were used as the boundary and initial conditions of a one-dimensional numerical thermal model to predict the internal temperatures of the material. The thermal conductivity of PEEK was estimated with the Continuous Genetic Algorithm optimization technique by searching for the coefficients of a functional form of thermal conductivity that minimized the difference between the experimentally measured and model predicted internal temperature values. The thermal testing, one-dimensional numerical thermal model, optimization algorithm, analysis, and results are presented.
Thermal Properties↗
Reusable surface insulations for reentry spacecraft
A family of ceramic, reusable surface insulations developed for the thermal protection of reentry vehicles is discussed. Their thermal properties are summarized and their thermal capabilities are compared. The insulation requirements for the Personnel Launch System are evaluated.
Chiu, S. Amanda↗
Evaluation of Coatings and Materials for Future Radiators
Radiators are used to reject energy from space vehicles through radiant heat transfer. They are typically the largest component in a vehicle's thermal control system and can have a large impact on the vehicle design and operation. NASA s current vision for exploration dictates that radiators for a Crew Exploration Vehicle (CEV), a Lunar Surface Access Module (LSAM), and a lunar base will need to be developed. These applications present new challenges when compared to previous radiators on the Space Shuttle and International Space Station (ISS). In addition, many technological advances have been made that could positively impact future radiator design. This paper outlines new requirements for future radiators and documents a trade study performed to select the some promising technologies for further evaluation. The technologies include K1100 based carbon composites for the radiator surface as well as Optical Solar Reflectors (OSRs), a lithium based white paint, and electrochromic thin films for optical coatings. Coupons were made using these materials and tests were performed to characterize their performance. Testing included evaluating structural and thermal properties of the carbon composites, thermal cycling, launch pad weather simulation, and exposure to solar wind, and Ultraviolet (UV) radiation.
Tuan, George C.↗
Engineering and design properties of thallium-doped sodium iodide and selected properties of sodium-doped cesium iodide
Mechanical and thermal properties, not available in the literature but necessary to structural design, using thallium doped sodium iodide and sodium doped cesium iodide were determined to be coefficient of linear thermal expansion, thermal conductivity, thermal shock resistance, heat capacity, elastic constants, ultimate strengths, creep, hardness, susceptibility to subcritical crack growth, and ingot variation of strength. These properties were measured for single and polycrystalline materials at room temperature.
Forrest, K.↗
Long-term stability and properties of zirconia ceramics for heavy duty diesel engine components
Physical, mechanical, and thermal properties of commercially available transformation-toughened zirconia are measured. Behavior is related to the material microstructure and phase assemblage. The stability of the materials is assessed after long-term exposure appropriate for diesel engine application. Properties measured included flexure strength, elastic modulus, fracture toughness, creep, thermal shock, thermal expansion, internal friction, and thermal diffusivity. Stability is assessed by measuring the residual property after 1000 hr/1000C static exposure. Additionally static fatigue and thermal fatigue testing is performed. Both yttria-stabilized and magnesia-stabilized materials are compared and contrasted. The major limitations of these materials are short term loss of properties with increasing temperature as the metastable tetragonal phase becomes more stable. Fine grain yttria-stabilized material (TZP) is higher strength and has a more stable microstructure with respect to overaging phenomena. The long-term limitation of Y-TZP is excessive creep deformation. Magnesia-stabilized PSZ has relatively poor stability at elevated temperature. Overaging, decomposition, and/or destabilization effects are observed. The major limitation of Mg-PSZ is controlling unwanted phase changes at elevated temperature.
Larsen, D. C.↗
Mechanical and thermal measurements on simulated lunar surface materials.
Mechanical and thermal properties of rock powders as lunar surface simulators
LUNAR SOIL↗
Thermal and Kinetic Properties of Motions in a Prominence Activation and Nearby Loop
We perform a quantitative analysis of the thermal properties of a prominence activation and motions in a nearby loop. In order to make measurements of the quickly moving features seen in prominences in the UV we use the SOHO/SUMER spectrograph to take a time series of exposures from a single pointing position, providing a measurement of spectral line properties as a function of time and position along the slit. The lines observed cover a broad range of temperatures from 80,000 - 1.6 million K. These measurements are combined with TRACE movies in transition region and coronal temperature bands to obtain more complete information concerning prominence structure and motions. The resulting observations allow us to analyze the thermal and kinetic energy of the moving sources as functions of time. The loop and prominence are most apparent in lines formed at temperatures below 250,000 K. We find that in most cases the temperature distribution of plasma in a moving feature changes relatively little over time periods of about 20 minutes.
Kucera, Therese↗
Regional sedimentological variations among dark crater floor features: Toward a model for modern eolian sand distribution on Mars
It has been known since 1972 that many Martian craters have dark features on their floors, and that when seen at higher image resolution, some of the dark units are dune fields. Interpretations of thermal inertia derived from Viking Infrared Thermal Mapper (IRTM) data have been used to suggest that many dark intracrater features, including those where dunes are not observed in images, contain some amount of sand or particles in the range 0.1-10 mm. However, it has never been known if all these dark features consist of dunes. We assembled a set of 108 carefully constrained Viking IRTM observations for dark crater-floor units. The data and selection criteria are described in detail elsewhere. Studied in conjunction with Mariner 9 and Viking orbiter images of each crater, these data indicate that the dark crater-floor units in some regions have different thermal properties than those in other regions. Thermal inertias were computed using the Viking thermal model of H. H. Kieffer and corrected for atmospheric CO2 effects using the relationship for a dust-free atmosphere shown by Haberle and Jakosky.
Edgett, K. S.↗
Performance evaluation of ''thermo-lag'' material for entry heat protection of advanced manned spacecraft. vol. 2- thermal investigations final report, 1 oct. 1962 - 31 jan. 1964
Thermal properties and performance of Thermo-lag material for entry heat protection of manned spacecraft
MANNED SPACECRAFT↗
Physical property measurements of doped cesium iodide crystals
Mechanical and thermal property values are reported for crystalline cesium iodide doped with sodium and thallium. Young's modulus, bulk modulus, shear modulus, and Poisson's ratio were obtained from ultrasonic measurements. Young's modulus and the samples' elastic and plastic behavior were also measured under tension and compression. Thermal expansion and thermal conductivity were the temperature dependent measurements that were made.
Synder, R. S.↗
Results of investigating thermal and electrical properties of lunar surface material and its analogs
Thermal and electrical properties are reported of lunar surface material returned to Earth by the Luna 16 automatic station and its terrestrial analogs studied in a vacuum and in a helium atmosphere. Study of the lunar surface material and its analogs showed that their specific heat capacity and electrical properties are similar in value but the coefficients of thermal conductivity differ. The results are compared with data on thermal and electrical properties of the surficial layer of the Moon obtained by indirect radiometric methods, and with results obtained for samples of lunar surface material returned to Earth by the crew of the Apollo 11 spacecraft.
Golovkin, A. R.↗
Computation of Variability in the Average Thermal and Mechanical Properties of a Melt-infiltrated Sic/sic Composite
Thermal conductivity and tensile properties (elastic modulus, proportional limit strength, inplane tensile strength, and strain to failure) of a SiC/SiC composite were experimentally determined at 816 and 1204 C. Tests were performed at room temperature on the same material to obtain interlaminar shear and tensile strength. For each thermal and mechanical property 24 tests were conducted to capture the variation. A random sampling method was used to quantify the variability exhibited by the mean values of the thermal and mechanical properties. The minimum number of tests required to characterize the mean value of each thermal or mechanical property for the composite was determined by varying the group size of the random sample.
Kalluri, Sreeramesh↗
Development of Vulcanizable Elastomers Suitable for Use in Contact with Liquid Oxygen Second Annual Summary Report, 9 May 1964 - 8 May 1965
Thermal properties of fluorine containing polymers for development of vulcanizable elastomers suitable for use in contact with liquid oxygen
POLYMER CHEMISTRY↗
Vapor Grown Carbon Fiber/Phenolic Matrix Composites for Rocket Nozzles and Heat Shields
The ablation and mechanical and thermal properties of vapor grown carbon fiber (VGCF)/phenolic resin composites were evaluated to determine the potential of using this material in solid rocket motor nozzles. Composite specimens with varying VGCF loading (30%-50% wt) including one sample with ex-rayon carbon fiber plies were prepared and exposed to a plasma torch for 20 s with a heat flux of 16.5 MW/sq m at approximately 1650 C. Low erosion rates and little char formation were observed, confirming that these materials were promising for rocket motor nozzle materials. When fiber loadings increased, mechanical properties and ablative properties improved. The VGCF composites had low thermal conductivities (approximately 0.56 W/m-C) indicating they were good insulating materials. If a 65% fiber loading in VGCF composite can be achieved, then ablative properties are projected to be comparable to or better than the composite material currently used on the Space Shuttle Reusable Solid Rocket Motor (RSRM).
Patton, R. D.↗
Determining norms from the basic electric parameters of connector contacts
Thermal property analysis of connector contacts to find basic electric parameters, and to determine norms for contact and transitional resistance valve
CONNECTOR↗
Development of Additive Manufacturing Technologies for 3D Printing of Spacecraft Heat Shields
Introduction: Ablative heat shields are an enabling technology for entry into planetary atmospheres. From the PICA heatshields used for several Mars rovers to the carbon phenolic material used for Galileo’s Jupiter entry probe, the heat shield manages the heat load transferred to the payload, protecting the sensitive scientific instruments carried on entry probes. The Additive Manufacturing of Thermal Protection Systems (AMTPS) project, an Early Career Initiative (ECI) funded by NASA’s Space Technology Mission Directorate and led by NASA Johnson Space Center, seeks to develop materials and processes for 3D printing ablative heat shields for spacecraft. Current methods for producing ablative heat shields are extremely labor intensive and re-quire extensive hands-on processes and quality control characterization. Additive manufacturing (AM) offers the possibility of reduced production times, improved reliability, and enhanced performance via graded compositions. Costs will also be reduced by reducing the time and labor required for heat shield production. Direct integration of the heat shield onto the structure during processing simplifies integration and reduces risk. Material Development: A critical challenge for the project is development of a material system that can (1) be printed in a near-net shape process and (2) perform well as an ablator. Achieving printability requires the material to flow under applied pressure, but maintain its shape once extruded from the printer nozzle. Ablative performance is measured by a multitude of markers, including char yield, char strength, thermal conductivity, and recession rate. Furthermore, there are several mechanical and thermal property considerations for vehicle integration including coefficient of thermal expansion (CTE) and residual stress. AM technology will be leveraged to grade the material formulation and properties through the thickness of the heat shield, an architecture not possible with current manufacturing processes. To this end, “robust” material formulations have been pre-pared with higher density for use on the surface where most ablation will occur. “Insulative” material formulations, with lower density and lower thermal conductivity, are prepared for use in the depth of the heat shield. This graded architecture will re-duce the overall mass of the heat shield and reduce costs and/or increase scientific payload capacities. To achieve a material system with the required properties, multiple resins have been investigated in collaboration with NASA Ames Research Center. To tune printability and performance, resin additives were studied to improve flexibility of the cured material while maintaining acceptable ablative performance. Material coupons were printed and studied via a suite of mechanical and thermal characterization methods. Arc jet testing was conducted at NASA Ames Research Center to evaluate ablative performance and thermal protection under conditions expected in atmospheric entry. Manufacturing Scale-Up: A partnership with Oak Ridge National Laboratory (ORNL) aims to enable full-scale fabrication of a 3D printed heat shield. Leveraging expertise in manufacturing and 3D printing at ORNL, a mid-scale manufacturing demonstration unit will be built and tested, using a dual-layer ablative system printed directly onto the titanium structure. Work on robotic system integration is ongoing and efforts to scale up material mixing with a material compound will ensure accurate and homogenous composition. Flight Test: A hypersonic sub-orbital flight test will provide a rigorous test of material performance ranging from ablation, thermal management, and mechanical integrity. Design of the capsule has taken place in collaboration with the University of Kentucky. Data collected from the flight will inform future design efforts in material formulation, printing methodology, and heat shield-capsule integration.
additive manufacturing↗