A method for the thermal analysis of spacecraft, including all multiple reflections and shading among diffuse, gray surfaces
Computer program for thermal analysis of spacecraft surfaces
Swofford, D. P.↗
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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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Interfacing a General Purpose Fluid Network Flow Program with the SINDA/G Thermal Analysis Program
A general purpose, one dimensional fluid flow code is currently being interfaced with the thermal analysis program Systems Improved Numerical Differencing Analyzer/Gaski (SINDA/G). The flow code, Generalized Fluid System Simulation Program (GFSSP), is capable of analyzing steady state and transient flow in a complex network. The flow code is capable of modeling several physical phenomena including compressibility effects, phase changes, body forces (such as gravity and centrifugal) and mixture thermodynamics for multiple species. The addition of GFSSP to SINDA/G provides a significant improvement in convective heat transfer modeling for SINDA/G. The interface development is conducted in multiple phases. This paper describes the first phase of the interface which allows for steady and quasi-steady (unsteady solid, steady fluid) conjugate heat transfer modeling.
Schallhorn, Paul↗
A Steady State and Quasi-Steady Interface Between the Generalized Fluid System Simulation Program and the SINDA/G Thermal Analysis Program
A general purpose, one dimensional fluid flow code is currently being interfaced with the thermal analysis program SINDA/G. The flow code, GFSSP, is capable of analyzing steady state and transient flow in a complex network. The flow code is capable of modeling several physical phenomena including compressibility effects, phase changes, body forces (such as gravity and centrifugal) and mixture thermodynamics for multiple species. The addition of GFSSP to SINDA/G provides a significant improvement in convective heat transfer modeling for SINDA/G. The interface development is conducted in multiple phases. This paper describes the first phase of the interface which allows for steady and quasisteady (unsteady solid, steady fluid) conjugate heat transfer modeling.
Schallhorn, Paul↗
Thermal analysis of a hypersonic wing test structure
The three-dimensional finite element modeling techniques developed for the thermal analysis of a hypersonic wing test structure (HWTS) are described. The computed results are compared to measured test data. In addition, the results of a NASA two-dimensional parameter finite difference local thermal model and the results of a contractor two-dimensional lumped parameter finite difference local thermal model will be presented.
Sandlin, Doral R.↗
Thermal analysis and study of arc-flow interactions in the anode regime of an electric arc Summary report
Thermal analysis and study of arc-flow in anode regime of electric arc
THERMAL PROPERTY↗
Differential thermal analysis studies of compound semiconductors
Phase equilibria and maximum melting compositions determinations for compound semiconductors by differential thermal analysis compared with vapor and high pressure techniques
Glatz, A. C.↗
Thermal Analysis and Testing of Fastrac Gas Generator Design
The Fastrac Engine is being developed by the Marshall Space Flight Center (MSFC) to help meet the goal of substantially reducing the cost of access to space. This engine relies on a simple gas-generator cycle, which burns a small amount of RP-1 and oxygen to provide gas to drive the turbine and then exhausts the spent fuel. The Fastrac program envisions a combination of analysis, design and hot-fire evaluation testing. This paper provides the supporting thermal analysis of the gas generator design. In order to ensure that the design objectives were met, the evaluation tests have started on a component level and a total of 15 tests of different durations were completed to date at MSFC. The correlated thermal model results will also be compared against hot-fire thermocouple data gathered.
Nguyen, H.↗
Preliminary thermal analysis of an aerodynamically shaped heat source for use with the isotope Brayton space power system
Two dimensional thermal analysis of aerodynamically shaped heat source during steady state operation with isotope Brayton space power system
Burns, R. K.↗
Determining the nucleation rate curve for lithium disilicate glass by differential thermal analysis
The crystallization of lithium disilicate (Li2O+2SiO2) glass nucleated at various temperatures was studied by differential thermal analysis (DTA). A plot of the DTA crystallization peak height versus nucleation temperature closely resembles the classical nucleation rate curve for lithium disilicate glass whose maximum is at 453 C. The glass becomes saturated with internal nuclei when heated at 453 C for 10 h. The activation energy for crystallization and the heat of crystallization are independent of the concentration of nuclei and are 249 + or - 10 and 67 + or - 3 kJ/mol, respectively. The Avrami exponent, n, depends strongly on the concentration of nuclei in the glass.
Ray, Chandra S.↗
Comparing the Electrical Modeling and Thermal Analysis Toolbox Simulation Data to Electrified Aircraft Propulsion Test Hardware Data
A model using the Electrical Modeling and Thermal Analysis Toolbox (EMTAT), a National Aeronautics and Space Administration (NASA)-developed Simulink® model block library of electrical components, was developed to mirror the Hybrid Propulsion Emulation Rig (HyPER) hardware, a laboratory focused on Electrified Aircraft Propulsion (EAP) hardware tests. The goal of the model was to demonstrate the utility of the library by comparing the accuracy of the library models to the performance of real hardware, with the primary metrics being the simulation outputs matching physical test hardware data within 5% of full scale.The objective of this paper is to present the background, setup, testing and results of this comparison. It describes some of the adjustments that were necessary to match the system hardware, as well as next steps in verification and validation. The outputs of the model were compared to the results of several tests in HyPER, and in the process captured an additional torque loss that is still being analyzed for the root cause but has been confirmed in the hardware. Across all the test series, only one key model parameter was outside the target 5% full scale matching, and nearly 70% were within 1%.
Mark E Bell↗
Comparing the Electrical Modeling and Thermal Analysis Toolbox Simulation Data to Electrified Aircraft Propulsion Test Hardware Data
A model using the Electrical Modeling and Thermal Analysis Toolbox (EMTAT), a National Aeronautics and Space Administration (NASA)-developed Simulink® model block library of electrical components, was developed to mirror the Hybrid Propulsion Emulation Rig (HyPER) hardware, a laboratory focused on Electrified Aircraft Propulsion (EAP) hardware tests. The goal of the model was to demonstrate the utility of the library by comparing the accuracy of the library models to the performance of real hardware, with the primary metrics being the simulation outputs matching physical test hardware data within 5 percent of full scale. The objective of this paper is to present the background, setup, testing and results of this comparison. It describes some of the adjustments that were necessary to match the system hardware, as well as next steps in verification and validation. The outputs of the model were compared to the results of several tests in HyPER, and in the process captured an additional torque loss that is still being analyzed for the root cause but has been confirmed in the hardware. Across all the test series, only one key model parameter was outside the target 5 percent full scale matching, and nearly 70 percent were within 1 percent.
Mark E. Bell↗
LANDSAT-D thermal analysis and design support
Detailed thermal models of the LANDSAT-D Earth Sensor Assembly Module (ESAM), the Dummy Thematic Mapper (DTM), and a small thermal model of the LANDSAT-D spacecraft for a heater analysis were developed. These models were used to develop and verify the thermal design of the ESAM and DTM, to evaluate the aeroheating effects on ESAM during launch and to evaluate the thermal response of the LANDSAT-D assuming the hard-line heaters failed on with the spacecraft in the Space Transportation System (STS) orbiter bay. Results of model applications are summarized.
Source record↗
TAP 1: A Finite Element Program for Steady-State Thermal Analysis of Convectively Cooled Structures
The program has a finite element library of six elements: two conduction/convection elements to model heat transfer in a solid, two convection elements to model heat transfer in a fluid, and two integrated conduction/convection elements to represent combined heat transfer in tubular and plate/fin fluid passages. Nonlinear thermal analysis due to temperature dependent thermal parameters is performed using the Newton-Raphson iteration method. Program output includes nodal temperatures and element heat fluxes. Pressure drops in fluid passages may be computed as an option. A companion plotting program for displaying the finite element model and predicted temperature distributions is presented. User instructions and sample problems are presented in appendixes.
Thornton, E. A.↗
Thermal Analysis of the MC1 Engine Turbopump
The MC1 Engine turbopump supplied the propellants to the main injector. The turbopump consisted of four parts; lox pump, interpropellant seal package (IPS), RP pump and turbine. The thermal analysis was divided into two 2D finite element models; Housing or stationary parts and rotor or rotating parts. Both models were analyzed at the same boundary conditions using SINDA. The housing model consisted of, lox pump housing, ips housing, RP housing, turbine inlet housing, turbine housing, exit guide vane, heat shield and both bearing outer races. The rotor model consisted of the lox impeller; lox end bearing and id race, RP impeller, and RP bearing and id race, shaft and turbine disk. The objectives of the analysis were to: (1) verified the original design and recommend modifications to it, (2) submitted a thermal environment to support the structural analysis, (3) support the component and engine test program. and (4) to support the X34 vehicle program.
Roman, Jose↗
Thermal Analysis of the MCI Engine Turbopump
The MCI Engine turbopump supplied the propellants to the main injector. The turbopump consisted of four parts; lox pump, interpropellant seal package (IPS), RP pump and turbine. The thermal analysis was divided into two 2D finite element models; Housing or stationary parts and rotor or rotating parts. Both models were analyzed at the same boundary conditions using SINDA. The housing model consisted of; lox pump housing, ips housing, RP housing, turbine inlet housing, turbine housing, exit guide vane, heat shield and both bearing outer races. The rotor model consisted of the lox impeller; lox end bearing and id race, RP impeller, and RP bearing and id race, shaft and turbine disk. The objectives of the analysis were to (1) verified the original design and recommend modifications to it, (2) submitted a thermal environment to support the structural analysis, (3) support the component and engine test program and (4) to support the X34 vehicle program.
Roman, Jose↗
Transient Thermal Analysis of the 12.5 KW HERMeS Hall Thruster
NASA’s Dawn spacecraft entered orbit around the dwarf planet Ceres on March 6, 2015 thereby becoming the first mission to orbit two celestial bodies outside of the Earth-moon system. This feat was made possible due to the use of electric propulsion (EP) to provide the 11 km/s of delta-V that was necessary. This type of propulsion is also enabling for many of NASA’s future missions, such as the proposed Asteroid Redirect Robotic Mission (ARRM). Specifically, the Hall Effect Rocket with Magnetic Shielding (HERMeS) is the propulsive design baseline due to its long operational lifetime and high specific impulse. Extensive modeling is required to verify the thruster's predicted thermal performance and survival during the bounding mission phases. Since the thruster would constrain plasma on the order of tens of thousands of hours, components in the thruster must be able to accommodate much higher sustained temperatures than typical spacecraft hardware. Furthermore, the high temperatures necessitate care in analyzing thermal gradients within the thruster. In this paper, we describe a thermal model of the HERMeS thruster and focus upon the thruster's transient performance under different initial firing conditions. The thruster's transient thermal response is critical to verify margin in the thermal stresses inherent in the thruster and to determine safe start-up procedures to protect the thruster's critical components. This model is used to perform transient thermal analysis of the thruster during startup and shutdown, provide temperature maps for structural analysis, and plan for thermal cycle testing conducted at JPL. The thermal cycle testing includes thruster starts at the cold temperature limits and operation at maximum expected external heat flux. This work will support laboratory environmental testing of the HERMeS thruster, which is being conducted at JPL in 2016.
Reilly, Sean↗
A Multi-scale Approach to Urban Thermal Analysis
An environmental consequence of urbanization is the urban heat island effect, a situation where urban areas are warmer than surrounding rural areas. The urban heat island phenomenon results from the replacement of natural landscapes with impervious surfaces such as concrete and asphalt and is linked to adverse economic and environmental impacts. In order to better understand the urban microclimate, a greater understanding of the urban thermal pattern (UTP), including an analysis of the thermal properties of individual land covers, is needed. This study examines the UTP by means of thermal land cover response for the Salt Lake City, Utah, study area at two scales: 1) the community level, and 2) the regional or valleywide level. Airborne ATLAS (Advanced Thermal Land Applications Sensor) data, a high spatial resolution (10-meter) dataset appropriate for an environment containing a concentration of diverse land covers, are used for both land cover and thermal analysis at the community level. The ATLAS data consist of 15 channels covering the visible, near-IR, mid-IR and thermal-IR wavelengths. At the regional level Landsat TM data are used for land cover analysis while the ATLAS channel 13 data are used for the thermal analysis. Results show that a heat island is evident at both the community and the valleywide level where there is an abundance of impervious surfaces. ATLAS data perform well in community level studies in terms of land cover and thermal exchanges, but other, more coarse-resolution data sets are more appropriate for large-area thermal studies. Thermal response per land cover is consistent at both levels, which suggests potential for urban climate modeling at multiple scales.
Gluch, Renne↗
Improvement of mixed time implicit-explicit algorithms for thermal analysis of structures
Computer implementation aspects and numerical evaluation of the recently introduced mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally useful method of estimating the critical time step for a linear quadrilateral element is given herein for the methods introduced by Liu and co-workers. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.
Liu, W. K.↗