MATHEMATICAL MODELING OF THE THERMAL STATE OF AN ISOTHERMAL ELEMENT WITH ACCOUNT OF THE RADIANT HEAT TRANSFER BETWEEN PARTS OF A SPACECRAFT

UDC 629.78 and S. O. Firsyuk A methodological approach to determination of the thermal state at a point on the surface of an isothermal element of a small spacecraft has been developed. A mathematical model of heat transfer between surfaces of intricate geometric confi guration has been described. In this model, account was taken of the external fi eld of radiant fl uxes and of the differentiated mutual infl uence of the surfaces. An algorithm for calculation of the distribution of the density of the radiation absorbed by surface elements of the object under study has been proposed. The temperature fi eld on the lateral surface of the spacecraft exposed to sunlight and on its shady side has been calculated. By determining the thermal state of magnetic controls of the orientation system as an example, the authors have assessed the contribution of the radiation coming from the solar-cell panels and from the spacecraft surface.