Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
This paper presents the developments of the new isocell quasi-
Monte Carlo ray tracing method for thermal analysis. The rationale
for this research is the speed-up of radiative heat transfer
computation with the Finite Element Method, widely used in mechanical
engineering especially for space structure design but not
yet often for thermal analysis of these structures.
Based on Nusselt’s analogy, the ray direction sampling is done
by sampling the unit disc to derive the ray directions. Stratified
sampling is applied to the unit disc that is divided into cells
or strata into which random points are generated. The isocell
method relies on cells that have the particularity of presenting almost
the same area and shape. This enhances the uniformity of
the generated quasi-random sequence of ray directions and leads
to faster convergence. The isocell method is associated with different
surface sampling to derive REFs. The method is benchmarked
against ESARAD, the standard ray tracing engine of the
thermal analysis software used in the European aerospace industry.
Various geometries are used. In particular, one entrance baffle
of the Extreme Ultraviolet Imager (EUI) instrument developed at
the Centre Spatial de Li`ege in Belgium is presented. The EUI
instrument of the Solar Orbiter European Space Agency mission
and will be launched in a 0.28 perihelion orbit around the Sun in
2018.
