Thermal Expansion for Charring Ablative Materials

Abstract

A mesh moving scheme is developed and tested in a finite-volume thermo-mechanical solver to investigate the effects of geometry deformation on thermal protection system materials. Verification cases are conducted to test the implementation of the moving mesh scheme. An iso-Q sample is used to demonstrate the swelling of thermal protection system materials on a realistic geometry. The results show that, under certain conditions, thermal expansion should not be ignored. The resulting local thermal strain reaches up to 30% and suggests that strain effects on the material properties should be considered. Moreover, the geometric expansion may also result in changes in the surrounding flow field, which may ultimately change the incoming heat flux and many boundary conditions.