Numerical investigation on actively cooled thermal protection systems with Ni-based alloys

One of the greatest challenges of hypersonic vehicles is their thermal protection and, more specifically, the cooling of their engine. To simulate the behavior of a complete actively cooled thermal protection system, a computational fluid dynamics and finite element analysis coupling method is applied to calculate the fluid/thermal/stress distributions for steady-state flight conditions. Work has been done on four different Ni-based alloys and three different panel structures. Temperature and stress profiles at the outlet cross section show that the maximum temperature and stress happen on the side that is close to the combustion chamber, and so this is the section on which the active cooling system should focus. It is better to have small rounded chamfers in the panels to decrease the stress concentration at the corners. Failure maps are presented for four Ni-based alloys showing the comparison of their thermostructural performance, which will be helpful for the selection of the materials in an active cooling system.