Spacecraft thermal modelling

Abstract

SUMMARYThermal 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 nowisothermal 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.

Nonempirical Design of Rapid Thermal Processing System

“…For the analysis and the optimization of the entire heat transport from the radiation heat source to the substrate in the RTP system, many researchers have studied the theoretical calculation models. 7,9,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] The next step is providing the technology to design the RTP system.…”

“…To achieve these objectives, the theoretical model should take into account the extremely complicated paths of the rays from the lamps to the silicon wafer surface in the threedimensional geometry of the reflectors, the lamps and the silicon wafer in the RTP system. This is the reason why the direct approach model using ray trace simulation (DARTS) has been developed [33][34][35] as an extension of the ray tracing method, [27][28][29][30][31][32] for achieving item (iii). In relation to item (i), the DARTS model successfully showed the temperature trend induced by the specular reflectors, such as the reflector tube 33) and the cylindrical reflectors.…”

Radiation heat transfer between diffuse-gray surfaces using higher order finite elements

“…Chin et al [3] discuss some of the problems associated with thermal modeling of spacecraft, and in particular the problems associated with computation of radiation heat transfer.…”

Optimal control of radiating panels via sequential quadratic programming

“…Various finite element (FE) schemes for the solution of thermal control problems have been used. Work that focuses directly on space structures includes Warren and Arelt (1991) and Chin et al (1992). Related FE schemes for other applications have been proposed, e.g.…”