High energy rapid modular ensemble of satellites payload thermal analysis using openfoam

In a space mission design, the goal of the thermal control subsystem is to ensure that all components of the satellite stay within their operating temperature ranges. The problem becomes more critical if the mission involves nanosatellites with an astrophysics payload requiring a dedicated thermal design to keep it at low temperature, as in the case of the High Energy Rapid Modular Ensemble of Satellites mission. Therefore, a thermal analysis is performed using ESATAN, one of the most-used software packages among those suggested by the European Cooperation for Space Standardization. This gives a good overview of the temperature fields, but many geometrical simplifications must be introduced in the model and all thermal interfaces must be checked. In order to assess the effect of the latter, the ESATAN results are cross checked with those obtained using another software, OpenFOAM, in which the geometry is created directly from the computer-aided-design model of the satellite, resulting in a very accurate geometrical representation. By first comparing the view factor calculations against analytical test cases, some issues emerged. These are thoroughly analyzed and discussed, and it is finally shown that they do not affect the temperature field. The high level of detail of OpenFOAM highlighted interesting possible improvements in the thermal configuration of the satellite.