Browsing by Keyword "Space Thermal Control"
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Item Accurate calculation of conductive conductances in complex geometries for spacecrafts thermal models(2016-02-15) Garmendia, Iñaki; Anglada, Eva; Vallejo, Haritz; Seco, Miguel; CIRMETAL; MAQUINASThe thermal subsystem of spacecrafts and payloads is always designed with the help of Thermal Mathematical Models. In the case of the Thermal Lumped Parameter (TLP) method, the non-linear system of equations that is created is solved to calculate the temperature distribution and the heat power that goes between nodes. The accuracy of the results depends largely on the appropriate calculation of the conductive and radiative conductances. Several established methods for the determination of conductive conductances exist but they present some limitations for complex geometries. Two new methods are proposed in this paper to calculate accurately these conductive conductances: The Extended Far Field method and the Mid-Section method. Both are based on a finite element calculation but while the Extended Far Field method uses the calculation of node mean temperatures, the Mid-Section method is based on assuming specific temperature values. They are compared with traditionally used methods showing the advantages of these two new methodsItem Thermal Control of Tribolab, a materials experiment in the International Space Station(Servicio de Publicaciones de la Universidad de Navarra, 2012-05) Garmendia, Iñaki; Anglada, Eva; Vallejo, Haritz; Brizuela, Marta; Insausti, NagoreTribolab is a materials tribology experiment that was flown on the International Space Station (ISS) from February 2008 to September 2009. The main objective of the experiment was the study of the behaviour of new solid lubricants (alloyed MoS2 with WC) under real space conditions. The thermal control of the instrument (techniques needed to ensure that the temperature range of the experiment components are adequate in all the mission possible scenarios) was designed, assembled, integrated and tested by a team of engineers of Inasmet-Tecnalia and INTA. The design concept employed, mainly passive thermal control with some active components, is explained in detail. The computational models devised for the design, as well as the different mission scenarios are also explained. The verification and on earth qualification tests are described and the difficulties encountered during the project for the thermal subsystem are also explained. Finally, the real thermal behaviour of the experiment when on space is described, with some post-flight information.