Thermal network method applications to problems related with the thermal analysis of small satellites.

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2002

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Okan, Altuğ

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In this thesis, the thermal network method is examined in detail and is applied to some problems related with the thermal analysis of small satellites. In satellites, dominant modes of heat transfer are the thermal radiation and conduction. In this research, energy exchanges among the surfaces of satellites are investigated. Also, the radiation exchange factors are determined which are necessary in radiation thermal analyses. A FORTRAN code 'TRANS" is developed. This code uses the thermal network method for thermal analysis. The code is applied to three problems and steady-state temperatures are obtained. In the first problem, two-dimensional heat transfer analysis of a square plate is performed. In the second problem, thermal analysis of a 111body forming a two-dimensional enclosure is investigated. In the third problem, thermal analysis of a body forming a three-dimensional enclosure which is made up of diffuse, gray and opaque surfaces is performed. The results are compared with the available analytical solutions and/or the results of commercial software packages. The comparisons indicate that the thermal network method gives accurate results. TRANS is also applied to the thermal analysis of GEZGİN printed circuit board which is one of the Turkish payloads on BİLSAT small satellite. For this problem, worst-case analysis is performed and maximum temperatures of critical components are calculated. The simulation results show that the temperatures of these components do not exceed their permitted operational limits.

Subject Keywords

Satellite thermal control, Numerical simulation, Combined radiation and conduction heat transfers, Thermal network method, Electronics cooling

URI

https://hdl.handle.net/11511/12848

Collections

Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

A. Okan, “Thermal network method applications to problems related with the thermal analysis of small satellites.,” Middle East Technical University, 2002.