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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 163 records · Page 9

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NASA NTRS1990

Space Station thermal control system evolution

The thermal control system (TCS) for the space station assembly complete configuration includes a two-phase central thermal bus with a supplemental body mounted radiator system. Evolution of the space station from a heat rejection capacity of 75 kW to 300 kW will require scars to expand the thermal fluid distribution network, equipment replacement to enable greater thermal transport capacity, and enlargement of the heat rejection subsystem for increased heat rejection. The TCS requirements for assembly completion and growth are presented along with a review of the basic structure of the active and passive thermal control systems which include provisions for growth.

Bullock, Richard L.↗

NASA NTRS1973

Shuttle active thermal control system development testing. Volume 3: Modular radiator system test data correlation with thermal model

Results are presented of an analysis which compares the performance predictions of a thermal model of a multi-panel modular radiator system with thermal vacuum test data. Comparisons between measured and predicted individual panel outlet temperatures and pressure drops and system outlet temperatures have been made over the full range of heat loads, environments and plumbing arrangements expected for the shuttle radiators. Both two sided and one sided radiation have been included. The model predictions show excellent agreement with the test data for the maximum design conditions of high load and hot environment. Predictions under minimum design conditions of low load-cold environments indicate good agreement with the measured data, but evaluation of low load predictions should consider the possibility of parallel flow instabilities due to main system freezing. Performance predictions under intermediate conditions in which the majority of the flow is not in either the main or prime system are adequate although model improvements in this area may be desired. The primary modeling objective of providing an analytical technique for performance predictions of a multi-panel radiator system under the design conditions has been met.

Phillips, M. A.↗

NASA NTRS1981

Thermal and aerothermal performance of a titanium multiwall thermal protection system

A metallic thermal protection system (TPS) concept the multiwall designed for temperature and pressure at Shuttle body point 3140 where the maximum surface temperature is approximately 811 K was tested to evaluate thermal performance and structural integrity. A two tile model of titanium multiwall and a model consisting of a low temperature reusable surface insulation (LRSI) tiles were exposed to 25 simulated thermal and pressure Shuttle entry missions. The two systems performed the same, and neither system deteriorated during the tests. It is indicated that redesign of the multiwall tiles reduces tile thickness and/or weight. A nine tile model of titanium multiwal was tested for radiant heating and aerothermodynamics. Minor design changes that improve structural integrity without having a significant impact on the thermal protection ability of the titanium multiwall TPS are identified. The capability of a titanium multiwall thermal protection system to protect an aluminum surface during a Shuttle type entry trajectory at locations on the vehicle where the maximum surface temperature is below 811 K is demonstrated.

Avery, D. E.↗

NASA NTRS2003

Thermal Performance Testing Of Cryogenic Piping Systems

Thermal performance measurement of piping systems under actual field conditions is important for space launch development and commercial industry. Knowledge of the true insulating effectiveness is needed in system design, development, and research activities. A new 18-meter-long test apparatus for cryogenic pipelines has been developed. Three different pipelines, rigid or flexible, can be tested simultaneously. Critical factors in heat leak measurements include eliminating heat transfer at end connections and obtaining proper liquid saturation condition. Effects due to variations in the external ambient conditions like wind, humidity, and solar radiation must be minimized. The static method of liquid nitrogen evaporation has been demonstrated, but the apparatus can be adapted for dynamic testing with cryogens, chilled water, or other working fluids. This technology is suited for the development of an industry standard test apparatus and method. Examples of the heat transfer data from testing commercially available pipelines are given. Prototype pipelines are currently being tested and evaluated at the Cryogenics Test Laboratory of NASA Kennedy Space Center.

Fesmire, J. E.↗

NASA NTRSDate not supplied

Modernization of Insulative Reusable Thermal Protection Systems (IRTPS)

Insulative thermal protection systems, such as Flexible Reusable Surface Insulation blankets and High Temperature Reusable Surface Insulation tiles, were developed for the Shuttle Orbiter to enable reuse of the vehicle for low-earth orbit missions. Since reusability is essential to many new industry launch and space vehicles, Shuttle-derived thermal protection materials (TPMs) are being sought for their flight proven performance. Alumina Enhanced Thermal Barrier (AETB) is the state-of-the-art tile material that was developed in the 90’s. AETB along with associated coatings, reaction cured glass (RCG) and Toughened Unipiece Fibrous Insulation (TUFI), are currently made by NASA using heritage raw materials derived from lifetime purchases. Finding viable replacements for raw materials that have changed in nature or are obsolete is important for continuation of these TPMs. In some cases, the use of modern raw materials has been shown to yield tile with reduced performance, most notably in mechanical properties. In this work, the production of AETB will be discussed to better understand the process-structure-property relationships and for allowing use of these modern alternatives. A small-scale tile casting system was developed for rapid and efficient exploration of the manufacturing variables such raw material selection and pre-processing, casting process parameters, and billet firing protocols. An optical transmission defect characterization technique was implemented to correlate process variables to structure. Comparisons between TUFI/RCG coated AETB derived from heritage and modern raw materials will be shown including AHF arc jet test results completed under a collaboration with Stratolaunch.

thermal protection materials↗

NASA NTRS1991

Use of the Long Duration Exposure Facility's thermal measurement system for the verification of thermal models

Results are presented of the comparison between the Long Duration Exposure Facility (LDEF) Thermal Measurements Systems (THERM) recorded temperature data and the predicted values as calculated prior to the LDEF deployment. The postflight thermal model was verified and calculated temperature uncertainties were reduced to under + or - 18 F from the preflight uncertainties of + or - 40 F. The THERM consisted of 8 temperature sensors, a shared tape recorder, a standard LDEF flight battery, and an electronics control box. The temperatures were measured at selected locations on the LDEF structure interior during the first 490 days of flight and recorded for postflight analysis. After the recorder was recovered from space, the tape recorder was recovered and the data reduced for comparison to the LDEF predicted temperatures. By comparing the calculated values to the measured data, a verified thermal model that presents the best agreement with the THERM data was obtained. The THERM experiment provided an economical way of performing a postflight verification of the LDEF Thermal Model by recording a limited number of flight temperatures on typical locations of the LDEF structure.

Berrios, William M.↗

NASA NTRS1980

Solar thermal power systems point-focusing thermal and electric applications projects. Volume 1: Executive summary

The activities of the Point-Focusing Thermal and Electric Applications (PETEA) project for the fiscal year 1979 are summarized. The main thrust of the PFTEA Project, the small community solar thermal power experiment, was completed. Concept definition studies included a small central receiver approach, a point-focusing distributed receiver system with central power generation, and a point-focusing distributed receiver concept with distributed power generation. The first experiment in the Isolated Application Series was initiated. Planning for the third engineering experiment series, which addresses the industrial market sector, was also initiated. In addition to the experiment-related activities, several contracts to industry were let and studies were conducted to explore the market potential for point-focusing distributed receiver (PFDR) systems. System analysis studies were completed that looked at PFDR technology relative to other small power system technology candidates for the utility market sector.

Marriott, A.↗

NASA NTRS2013

Monitoring of Thermal Protection Systems Using Robust Self-Organizing Optical Fiber Sensing Networks

The general aim of this work is to develop and demonstrate a prototype structural health monitoring system for thermal protection systems that incorporates piezoelectric acoustic emission (AE) sensors to detect the occurrence and location of damaging impacts, and an optical fiber Bragg grating (FBG) sensor network to evaluate the effect of detected damage on the thermal conductivity of the TPS material. Following detection of an impact, the TPS would be exposed to a heat source, possibly the sun, and the temperature distribution on the inner surface in the vicinity of the impact measured by the FBG network. A similar procedure could also be carried out as a screening test immediately prior to re-entry. The implications of any detected anomalies in the measured temperature distribution will be evaluated for their significance in relation to the performance of the TPS during re-entry. Such a robust TPS health monitoring system would ensure overall crew safety throughout the mission, especially during reentry

Structural Health Monitoring↗

NASA NTRS1992

Use of the Long Duration Exposure Facility's thermal measurement system for the verification of thermal models

The Long Duration Exposure Facility (LDEF) postflight thermal model predicted temperatures were matched to flight temperature data recorded by the Thermal Measurement System (THERM), LDEF experiment P0003. Flight temperatures, recorded at intervals of approximately 112 minutes for the first 390 days of LDEF's 2105 day mission were compared with predictions using the thermal mathematical model (TMM). This model was unverified prior to flight. The postflight analysis has reduced the thermal model uncertainty at the temperature sensor locations from +/- 40 F to +/- 18 F. The improved temperature predictions will be used by the LDEF's principal investigators to calculate improved flight temperatures experienced by 57 experiments located on 86 trays of the facility.

Berrios, William M.↗

NASA NTRS2014

Monitoring of Thermal Protection Systems and MMOD using Robust Self-Organizing Optical Fiber Sensing Networks

The general aim of this work is to develop and demonstrate a prototype structural health monitoring system for thermal protection systems that incorporates piezoelectric acoustic emission (AE) sensors to detect the occurrence and location of damaging impacts, such as those from Micrometeoroid Orbital Debris (MMOD). The approach uses an optical fiber Bragg grating (FBG) sensor network to evaluate the effect of detected damage on the thermal conductivity of the TPS material. Following detection of an impact, the TPS would be exposed to a heat source, possibly the sun, and the temperature distribution on the inner surface in the vicinity of the impact measured by the FBG network. A similar procedure could also be carried out as a screening test immediately prior to re-entry. The implications of any detected anomalies in the measured temperature distribution will be evaluated for their significance in relation to the performance of the TPS during reentry. Such a robust TPS health monitoring system would ensure overall crew safety throughout the mission, especially during reentry.

Fiber Optic Sensors↗

NASA NTRSDate not supplied

Multiscale Thermal Conductivity Modeling of 3D Woven Composite Thermal Protection System Materials

Novel thermal protection systems (TPS) for re-entry and hypersonic vehicles utilize 3D woven composite materials with blended carbon filament tows (yarns) and a phenolic resin matrix. The presence of continuous carbon fibers provides superior stiffness and strength compared to legacy TPS, while the 3D weave pattern provides a great deal of design flexibility for both in-plane and through thickness thermomechanical behavior. However, modeling of 3D woven composites is notoriously complex and numerically intensive. The present investigation utilizes a unique ultra-efficient approach, known as Multiscale Recursive Micromechanics (MsRM), wherein recursive semi-analytical micromechanics methods are employed at various length scales within the composite. The MsRM approach has recently been extended to solve for the effective thermal conductivity as well as the local temperature and thermal flux fields throughout the composite. Presented model results focus on the impact of the microstructural geometry representation at each length scale on the material’s effective thermal conductivity, along with the local thermal flux and temperature fields induced in the microstructures, for a novel 3D woven TPS.

Composite↗

NASA NTRSDate not supplied

TPS Certification by Analysis: Model-Driven Characterization of Properties and Failure in Woven Thermal Protection Systems

Woven, ablative thermal protection system (TPS) materials provide a robust option for aggressive (re)entries and thus have been baselined for the upcoming Mars Sample Return (MSR) mission's Earth Entry System (EES). The reliability requirements for MSR-EES necessitate understanding of material property variability, which could be significant given the complex structure and anisotropic nature of properties in TPS weaves, as well as the response to potential impact with micrometeoroids or orbital debris during the EES re-entry. The TPS Certification by Analysis effort within the Entry Systems Modeling project seeks to provide computational models and analyses that support the certification against such material-based risks. For the present talk, focus will be given to the characterization of baseline woven TPS material properties and mechanical failure limits, which entails (1) use of computational techniques (e.g., machine learning) to interpret computed tomography images of the weave to generate representative structural models and (2) application of multiscale material modeling approaches to characterize thermomechanical and failure properties.

thermal protection systems↗

NASA NTRS2018

Assessment of the Mars Helicopter Thermal Design Sensitivities Using the Veritrek Software

The Mars Helicopter will be a technology demonstration conducted during the Mars 2020 mission. The primary mission objective is to achieve several 90-second flights and capture visible light images via forward and nadir mounted cameras. These flights could possibly provide reconnaissance data for sampling site selection for other Mars surface missions. The helicopter is powered by a solar array, which stores energy in secondary batteries for flight operations, imaging, communications, and survival heating. The helicopter thermal design is driven by minimizing survival heater energy while maintaining compliance with allowable flight temperatures in a variable thermal environment. Due to the small size of the helicopter and its complex geometries, along with the fact that it operates with very low power and small margins, additional care had to be paid while planning thermal tests and designing the thermal system. A Thermal Desktop® model has been developed to predict the thermal system’s performance. A reduced-order model (ROM) created with the Veritrek software has been utilized to explore the sensitivities of the thermal system’s drivers, such as electronics dissipations, gas gaps, heat transfer coefficients, etc., as well as to assess and verify the final thermal design. This paper presents the performance of the Veritrek software products and the details of the ROM creation process. The results produced by Veritrek were utilized to study the effect of the major thermal design drivers and Mars environment on the Mars Helicopter in as little as 10 days, an effort that would have taken over 4 months using traditional thermal analysis techniques.

Hengeveld, Derek W.↗

NASA NTRS1981

Materials Experiment Carrier Thermal Control System study

The Materials Experimental Carrier (MEC) vehicle currently under study at NASA-Marshall Space Flight Center presents unique power and heat rejection problems to the 25 kW Power System (PS). In order to determine how these requirements can best be met on both the Power System and MEC vehicle, Thermal Control System Trade Studies were conducted. The results of these trade studies indicated total weight to orbit would be minimized for multiple MEC launches by centralized radiators on the Power System. A split loop arrangement of Power System Thermal Control Subsystem, with separate loops for payload and PS heat rejection, appeared favorable from these trades. FC72 fluid was recommended for the high temperature MEC heat transport loop.

Fleming, M.↗

NASA NTRS2001

Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report

During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

Wieland, P. O.↗

NASA NTRS2007

Heath Monitoring of Thermal Protection Systems - Preliminary Measurements and Design Specifications

The work reported here is the first stage of a project that aims to develop a health monitoring system for Thermal Protection Systems (TPS) that enables a vehicle to safely re-enter the Earth's atmosphere. The TPS health monitoring system is to be integrated into an existing acoustic emissions-based Concept Demonstrator, developed by CSIRO, which has been previously demonstrated for evaluating impact damage of aerospace systems.

Scott, D. A.↗

NASA NTRS2008

Atomizer for thermal management system

An atomizer for thermal management system for efficiently thermally managing one or more heat producing devices. The atomizer for thermal management system includes a housing having a coolant passage and a dispensing end, an orifice within the dispensing end, and an actuator manipulating a plunger within the housing. The plunger includes a head that is sealable within a recessed portion of the orifice to open or close the orifice. The coolant passes through the coolant passage into the orifice for spraying upon a heat producing device. The actuator may reciprocate so that the coolant spray emitted through the orifice is pulsating. The pulsing frequency may be increased to increase cooling or decreased to decrease cooling of the heat producing device.

Tilton, Charles L.↗

NASA NTRSDate not supplied

Thermal Protection Systems and Materials

Thermal protection systems protect space vehicles from aerodynamic heating during entry into planetary atmospheres. The Thermal Protection Materials Branch combines experiment, fabrication, characterization, evaluation, analysis and modeling to support NASA missions and collaborates externally to technology transfer thermal protection materials and tools to commercial or other agency partners.

Modeling↗