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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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Relationships among physical properties as indicators of high temperature deformation or post-shock thermal annealing in ordinary chondrites
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Evaluation of torque relaxation screw thread forms vs. thermal shock
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Sunrise/sunset thermal shock disturbance analysis and simulation for the TOPEX satellite
It is shown here that during normal on-orbit operations the TOPEX low-earth orbiting satellite is subjected to an impulsive disturbance torque caused by rapid heating of its solar array when entering and exiting the earth's shadow. Error budgets and simulation results are used to demonstrate that this sunrise/sunset torque disturbance is the dominant Normal Mission Mode (NMM) attitude error source. The detailed thermomechanical modeling, analysis, and simulation of this torque is described, and the predicted on-orbit performance of the NMM attitude control system in the face of the sunrise/sunset disturbance is presented. The disturbance results in temporary attitude perturbations that exceed NMM pointing requirements. However, they are below the maximum allowable pointing error which would cause the radar altimeter to break lock.
Tempered glass and thermal shock of ceramic materials
A laboratory experiment is described that shows students the different strengths and fracture toughnesses between tempered and untempered glass. This paper also describes how glass is tempered and the materials science aspects of the process.
Resistance of Six Cast High-temperature Alloys to Cracking Caused by Thermal Shock
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Thermal Shock Resistance and High-temperature Strength of a Molybdenum Disilicide - Aluminum Oxide Ceramic
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Turbojet Engine Investigation of Effect of Thermal Shock Induced by External Water-spray Cooling on Turbine Blades of Five High-temperature Alloys
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Solar Pumped High Power Solid State Laser for Space Applications
Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.
Thermostructural Analysis of the SOFIA Fine Field and Wide Field Imagers Subjected to Convective Thermal Shock
The originally designed SOFIA aircraft configuration included a system to pre-cool the telescope cavity on the ground before flight, however, due to various factors in the history of the project that system was not installed. This lack of ground pre-cooling was thus the source of the concern over whether or not the imagers would be exposed to a potentially unsafe thermostructural environment when the telescope cavity door was opened at altitude. This concern was in addition to the already existing concern that the air temperature rate of change during flight (both at the same altitude as well as ascent or descent) could cause the imagers to be exposed to an unsafe thermostructural environment. Four optical components were identified as the components of concern - two of higher concern (one in each imager) and two of lower concern (one in each imager). The requirement was to perform transient, coupled thermostructural analyses to determine whether the stress would ever achieve unsafe levels in these components. The analysis effort began by analyzing one component, after which the analyses for the other components was deemed unnecessary.
Thermostructural Analysis of the SOFIA Fine Field and Wide Field Imagers Subjected to Convective Thermal Shock
The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a highly modified Boeing 747-SP with a 17- ton infrared telescope installed in the aft portion of the aircraft. Unlike ground- and space-based platforms, SOFIA can deploy to make observations anytime, anywhere, in the world. The originally designed aircraft configuration included a ground pre-cool system, however, due to various factors in the history of the project, that system was not installed. This lack of ground pre-cooling was the source of the concern about whether or not the imagers would be exposed to a potentially unsafe thermostructural environment. This concern was in addition to the already-existing concern of some project members that the air temperature rate of change during flight (both at the same altitude as well as ascent or descent) could cause the imagers to be exposed to an unsafe thermostructural environment. Four optical components were identified as the components of concern: two of higher concern (one in each imager), and two of lower concern (one in each imager). The analysis effort began by analyzing one component, after which the analyses for the other components was deemed unnecessary. The purpose of this report is to document these findings as well as lessons learned from the effort.
Thermal expansion fluid flow and thermal shock of cement and a cement/steel interface at elevated pressure and temperature.
Abstract not provided.
Thermal expansion fluid flow and thermal shock of cement and a cement/steel interface at elevated pressure and temperature.
Abstract not provided.
Thermal expansion, fluid flow, and thermal shock of cement and a cement/steel interface at elevated pressure and temperature .
Abstract not provided.
Thermal Expansion of Simulated Wellbores Subjected to Thermal Shock Conditions
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Super-hydrophobic, thermally insulating, thermal-shocks resistant well cement composites for completion of geothermal wells at hydrothermal temperatures of up to 300° C
A well cement composite and a method for making a well cement composite includes a mixture of calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS; sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of the mixture of CAC and CS; polymethylhydrosiloxane (PMHS) in an amount of from 0.5 to 6.0% of the total weight of the mixture of CAC and CS; and water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.
Evaluation of oxidation resistant nonmetallic materials at 1204 C (2200 F) in a Mach 1 burner
Specimens of 23 oxidation resistant, nonmetallic, refractory materials were systematically exposed in a high gas velocity burner to simulate a turbine engine environment. Isothermal and cyclic tests were conducted at a specimen temperature of 2200F which resulted from exposure to Mach 1 or Mach 0.5 hot gas streams. Specimen behavior was judged on the basis of failure mode, appearance, and weight change. SiC and Si3N4 exhibited the most promising behavior surviving all exposures including Mach 1 for 120 cycles (10 hr). Major failure modes identified for other materials were thermal shock, thermal fatigue, and mechanical failure due to gas loading.