SPACECRAFT THERMAL MODELING

Thermal modelling of spacecraft requires approaches which can handle dominant radiative heat transfers and many special thermal control components. Present network-type thermal analysers allow simulation, especially for components with rectangular geometries, but at the expense of considerable awkwardness and much error-prone manual input. The user interfaces for pre- and postprocessing for these analysers are also very deficient. Finite element thermal analysers solve some of the analytical difficulties, but are not widely used because they lack the flexibility to simulate special operations. The Galerkin finite element method (GFEM) distributes the contributions within an element to the element nodal points. The assembly of the contributions from all elements yields a system of energy balance equations for the nodal points of the system. Monte Carlo raytracing, in conjunction with a GFEM energy distribution to element nodal points, yields a procedure of consistent non-isothermal surface radiation exchange. This procedure reduces a source of simulation error caused by non-uniform element illumination and shading. Orbital heating, fluid flow and special analysis features are discussed. The main analysis program is interfaced to the preprocessing and postprocessing modules. Example results are given.