An immersed boundary approach for hypersonic flows

In this work a well-established Immersed Boundary (IB) approach for the Favre-Averaged Navier--Stokes equations is employed in order to solve hypersonic flows occurring around space capsules entering planetary atmospheres or around hypersonic vehicles developed for future transcontinental flights or military applications. The strong shock wave that forms at such speeds excites molecules and activates chemical reactions, making the calorically perfect gas assumption absolutely inaccurate. Moreover, thermochemical non-equilibrium has to be taken into account since the fluid dynamic characteristic time is comparable with the thermal and chemical ones. In this scenario the aim of this work is to show the capabilities of the IB approach to cope with thermochemical non-equilibrium effects by using the well-known Park two-temperature model. Two dimensional simulations of a convergent-divergent nozzle and of several flows past a circular cylinder have been investigated. The results obtained with the IB approach have been compared with those obtained both experimentally and with a well-established body fitted solver.