Stability of fluid–structure thermal simulations on moving grids

This article analyses the stability of a thermally coupled fluid–structure interaction problem with a moving interface. Two types of fluid and structural discretizations are investigated: finite‐difference/finite‐difference as well as the more traditional finite‐volume/finite‐element (FV/FE) configuration. In either case, the material properties and grid spacing are treated as uniform within each domain. A theoretical stability analysis and corresponding numerical tests show that greater stability is associated with the algorithm in which the fluid domain is passed a Dirichlet condition and the solid domain a von Neumann condition and that the stability of the coupled scheme may be strongly affected by the interface velocity. Furthermore, it shows that the interface velocity has a larger destabilizing effect on the FV/FE discretization than on a finite‐difference/finite‐difference discretization.