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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 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Crystallization Kinetics of a Solid Oxide Fuel Cell Seal Glass by Differential Thermal Analysis

Crystallization kinetics of a barium calcium aluminosilicate glass (BCAS), a sealant material for planar solid oxide fuel cells, have been investigated by differential thermal analysis (DTA). From variation of DTA peak maximum temperature with heating rate, the activation energy for glass crystallization was calculated to be 259 kJ/mol. Development of crystalline phases on thermal treatments of the glass at various temperatures has been followed by powder x-ray diffraction. Microstructure and chemical composition of the crystalline phases were investigated by scanning electron microscopy and energy dispersive spectroscopic (EDS) analysis. BaSiO3 and hexacelsian (BaAl2Si2O8) were the primary crystalline phases whereas monoclinic celsian (BaAl2Si2O8) and (Ba(x), Ca(y))SiO4 were also detected as minor phases. Needle-shaped BaSiO3 crystals are formed first, followed by the formation of other phases at longer times of heat treatments. The glass does not fully crystallize even after long term heat treatments at 750 to 900 C.

Bansal, Narottam P.↗
DOE OSTI2024

Thermal Analysis of a 100 kW Polyphase Wireless Power Transfer System

Charging Electric Vehicles (EVs) fast and safely has a crucial role in the future of the EV technology. High-power Wireless Power Transfer (WPT) helps to significantly decrease the charging time. However, when the power transfer levels increase, thermal management becomes a significant challenge. The thermal design of the WPT systems needs more consideration in the design and implementation steps. This paper presents a thermal analysis of a 100 kW high-power WPT system. The thermal performance of the proposed design was evaluated at different power levels by considering the magnetic design and loss analysis. Finite Element Analysis (FEA) of the proposed design was performed and the thermal images of the implemented system were taken to prove the simulation results. The results show that, a liquid cooling design is needed for a high-power WPT systems for the long-time continuous operations of the charging pads.

Aydin, Emrullah↗
NASA NTRS1979

Sounding rocket thermal analysis techniques applied to GAS payloads

Simplified analytical techniques of sounding rocket programs are suggested as a means of bringing the cost of thermal analysis of the Get Away Special (GAS) payloads within acceptable bounds. Particular attention is given to two methods adapted from sounding rocket technology - a method in which the container and payload are assumed to be divided in half vertically by a thermal plane of symmetry, and a method which considers the container and its payload to be an analogous one-dimensional unit having the real or correct container top surface area for radiative heat transfer and a fictitious mass and geometry which model the average thermal effects.

Wing, L. D.↗
NASA NTRS1985

Reduction method for thermal analysis of complex aerospace structures

A reduction method which combines classical Rayleigh-Ritz modal superposition techniques with contemporary finite-element methods is applied to transient nonlinear thermal analysis of aerospace structures. The essence of the method is the use of a few thermal modes from eigenvalue analyses as basis vectors to represent the temperature response in the structure. The method is used to obtain approximate temperature histories for a portion of the Shuttle orbiter wing subject to reentry heating and for a large space antenna reflector subject to heating associated with a low Earth orbit. The reduction method has excellent potential for significant size reduction for radiation-dominated problems such as the antenna reflector. However, for conduction-dominated problems such as the Shuttle wing, especially those with complex spatial and temporal variations in the applied heating, additional work appears necessary to find alternate sources of basis vectors which will permit significant problem size reductions.

Shore, C. P.↗
NASA NTRS2001

Thermal Analysis of a High-Speed Aircraft Wing Using p-Version Finite Elements

This paper presents the results of conceptual level thermal analyses of a High Speed Civil Transport (HSCT) wing using p-version finite elements. The work was motivated by a thermal analysis of a HSCT wing structure which showed the importance of radiation heat transfer throughout the structure. The analysis also showed that refining a traditional finite element mesh to accurately capture the temperature distribution on the internal structure led to very large meshes with unacceptably long execution times. Further study indicated using p-version finite elements might improve computation performance for this class of problem. Methods for determining internal radiation heat transfer were then developed and demonstrated on test problems representative of the geometry found in an aircraft wing structure. This paper presents the results of the application of these new methods to the analysis of a high speed aircraft wing. Results for both a wing box model as well as a full wing model are presented. 'Me reduced wing box model allows for a comparison of the traditional finite element method with mesh refinement (h-refinement) to the new p-version finite elements while the full wing model demonstrates the applicability and efficiency of p-version finite elements for large models.

Gould, Dana C.↗
DOE OSTI2024

Thermal Analysis of the Sirius-3 Nuclear Propulsion Fuel Experiments

To support long space missions, NASA is designing and testing different fuels for nuclear thermal propulsion. These designs include a number ceramic metallic fuels which are to be irradiated in the Tranisent Test Reactor to test the fuel’s performance at protypical conditions. The irradiation campaign of these fuels is referred to as the Sirius experiments, and includes single and stacked experiment samples. In this paper we present the thermal analysis of the Sirius-3 experiment. For this analysis, temperatures from a Bison finite element model are compared to the temperatures obtained from an experiment thermocouple where good agreement between the two are found. Because agreement of the thermocouple and Bison finite element model, insight into the heat flow is provided to experimenters as they design future experiments. As an example of this insight, the rods through the fuel specimen as shown in Sirius A and B [1] were removed and replaced with hold down rings for the Sirius-2C

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2020

Thermal analysis of non-actinide bearing salt

The Netzsch STA 409 CD 403/5/G STA-MS Skimmer Coupling System was used to perform thermal analysis on FLiNaK to establish a method for characterizing vapor pressures over molten salts. The measurements include differential scanning calorimetry, thermogravimetry, and mass spectrometry to generate comprehensive thermochemical property data as stand-alone information to aid in MSR design and licensing as well as inputs into the Molten Salt Thermodynamic Database (MSTDB). The FY20 focus is to establish procedures and quantify uncertainty levels for measurements of non-actinide compositions for moving toward actinide bearing salt measurements in FY21.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Thermal Analysis of the Bus Bars for the 800MeV Injection Era (Fermilab Summer School 2023)

My internship at IARC has been focused on the thermal analysis of the bus bars of the Booster. The bus bars are the conductors that bring the bias current from the bias supply to the ferrite tuners in each RF cavity of the synchrotron. Since they are not superconductors, during normal operations they will heat up due to the Joule effect. The goal of my work is to build a model of the bus bars assembly that describes effectively the experimental data and that can be used to predict the temperature increase and distribution among the components of the assembly, in present and future operational conditions.

43 PARTICLE ACCELERATORS↗
NASA NTRS2002

Thermal Analysis of Next-Generation Space Telescope (NGST) Mirrors During Optical Testing in the X-Ray Calibration Facility (XRCF)

This paper presents Thermal Analysis of the Next Generation Space Telescope (NGST) Mirrors During Optical Testing in the X-Ray Calibration Facility (XRCF). The contents include: 1) NGST Spacecraft Concept; 2) NGST Mirror Development Testing; 3) NGST Development Mirror; 4) Knudsen Number; 5) Free-Molecular Conduction; 6) Accomodation Coefficient; and 7) Results and Recommendations. This paper is presented in viewgraph form.

Page, Tim↗
DOE OSTI2020

Thermal Analysis of a Superconducting Undulator Cryostat for the APS Upgrade

The Advanced Photon Source Upgrade includes four 4.8-m-long superconducting undulator (SCU) cryostats, each containing two planar undulator NbTi magnets up to 1.9 m long. The cooling is provided by six cryocoolers arranged in three thermal circuits. The magnets are indirectly cooled with LHe penetrating through channels in the magnet cores. This 4 K circuit, which also includes a LHe tank, is cooled by five 4 K cryocooler 2nd stages. A beam vacuum, which is thermally isolated from the magnets, is cooled by one 10 K cryocooler 2nd stage. A thermal shield and warm parts of current leads are cooled by the 1st stages of all six cryocoolers. This paper presents an ANSYS-based thermal analysis of the new SCU cryostat including all thermal circuits. The benchmarked thermal conductance between the cryocooler cold heads and the LHe tank are used in the calculations as well as the measured cryocooler load lines. The model predicts temperatures in the system, total 4 K heat loads, and excess cooling power for various operational modes of the undulator.

Shiroyanagi, Y.↗
NASA NTRS1971

Computer program for thermal analysis of shadow shields in a vacuum

Computer program determines temperature profiles and heat transfer rates for shadow shielded cryogenic tank. Tank, shields, and thermal radiation heat source are all axisymmetric. Thermal analysis considers varying shield and tank temperatures, surface properties, and geometric arrangements. Similar heat source properties are also considered.

Boyle, R. J.↗
NASA NTRS1983

Orbital thermal analysis of lattice structured spacecraft using color video display techniques

A color video display technique is demonstrated as a tool for rapid determination of thermal problems during the preliminary design of complex space systems. A thermal analysis is presented for the lattice-structured Earth Observation Satellite (EOS) spacecraft at 32 points in a baseline non Sun-synchronous (60 deg inclination) orbit. Large temperature variations (on the order of 150 K) were observed on the majority of the members. A gradual decrease in temperature was observed as the spacecraft traversed the Earth's shadow, followed by a sudden rise in temperature (100 K) as the spacecraft exited the shadow. Heating rate and temperature histories of selected members and color graphic displays of temperatures on the spacecraft are presented.

Wright, R. L.↗
NASA NTRS1985

Thermal analysis of the ACCESS space truss

This paper introduces the Assembly Concept for the Construction of Erectable Space Structure (ACCESS) experiment and describes the thermal requirements in detail. The experiment, an erectable truss beam to be flown and assembled aboard the Space Shuttle, was thermally modeled using the TRASYS and SINDA computer codes. Results from the thermal analysis are presented. Development tests dictate the application of a metallized film insulation on the aluminum beam struts to control transient orbital temperature extremes.

Foss, R. A.↗
NASA NTRS1990

An adaptive refinement procedure for transient thermal analysis using nodeless variable finite elements

An adaptive mesh refinement procedure that uses nodeless variables and quadratic interpolation functions is presented for analyzing transient thermal problems. A temperature based finite element scheme with Crank-Nicolson time marching is used to obtain the thermal solution. The strategies used for mesh adaption, computing refinement indicators, and time marching are described. Examples in one and two dimensions are presented and comparisons are made with exact solutions. The effectiveness of this procedure for transient thermal analysis is reflected in good solution accuracy, reduction in number of elements used, and computational efficiency.

Ramakrishnan, R.↗
NASA NTRS2001

Thermal Analysis Of The NASA Integrated Vehicle Health Monitoring Experiment Technology For X-Vehicles (NITEX)

The purpose of this project was to perform a thermal analysis for the NASA Integrated Vehicle Health Monitoring (IVHM) Technology Experiment for X-vehicles (NITEX). This electronics package monitors vehicle sensor information in flight and downlinks vehicle health summary information via telemetry. The experiment will be tested on the X-34 in an unpressurized compartment, in the vicinity of one of the vehicle's liquid oxygen tanks. The transient temperature profile for the electronics package has been determined using finite element analysis for possible mission profiles that will most likely expose the package to the most extreme hot and cold environmental conditions. From the analyses, it was determined that temperature limits for the electronics would be exceeded for the worst case cold environment mission profile. The finite element model used for the analyses was modified to examine the use of insulation to address this problem. Recommendations for insulating the experiment for the cold environment are presented, and were analyzed to determine their effect on a nominal mission profile.

Hegab, Hisham E.↗
NASA NTRS2002

Thermal Analysis of the NASA Integrated Vehicle Health Monitoring Experiment Technology for X-Vehicles (NITEX)

The purpose of this project was to perform a thermal analysis for the NASA Integrated Vehicle Health Monitoring (IVHM) Technology Experiment for X-vehicles (NITEX). This electronics package monitors vehicle sensor information in flight and downlinks vehicle health summary information via telemetry. The experiment will be tested on the X-34 in an unpressurized compartment, in the vicinity of one of the vehicle's liquid oxygen tanks. The transient temperature profile for the electronics package has been determined using finite element analysis for possible mission profiles that will most likely expose the package to the most extreme hot and cold environmental conditions. From the analyses, it was determined that temperature limits for the electronics would be exceeded for the worst case cold environment mission profile. The finite element model used for the analyses was modified to examine the use of insulation to address this problem. Recommendations for insulating the experiment for the cold environment are presented, and were analyzed to determine their effect on a nominal mission profile.

Hegab, Hisham E.↗