Calculation of linear conductances for thermal lumped models by means of the CMF method

A new method for improving the calculation of the linear conductances of components for lumped parameters thermal models is presented. The here called Conductance Matrix Fitting (CMF) method is based on the generation of a detailed lumped thermal model of the component. After setting-up the detailed model, it is condensed to create a reduced model. The unknown conductances of the reduced model are automatically calculated by correlating the temperature and heat flow of the reduced model with the results of the detailed model. The conductances of the component determined in this way can be used in the modelization of the complete device. A method to determine the temperature uncertainties of the reduced model, compared to the detailed one, is also presented. Finally, the method is validated using a one-dimensional example, and is applied to a real case in the context of the ESA Solar Orbiter mission.