Two-dimensional deforming finite element methods for surface ablation

This paper discusses the application of novel deforming finite element techniques to two-dimension al problems with moving boundaries caused by ablation. It is shown that deforming-grid techniques imply the construction of an additional convective matrix acting on the temperature unknowns. Surface ablation is taken into account by special boundary thermal loads. The usual finite elements are thus easily transformed for deforming grid purposes and allow for a precise tracking of the steep thermal gradients and localization of the surface. The numerical difficulties experienced in the procedure are discussed and solved. Illustration of the technique is made on model one- and two-dimensional axisymmetrical problems with carbonaceous and insulating materials. c fc fm g gc>Sc gf, g* gm h H Ha Hc Hm k Lf M rij N 91 pe qe q( s sc