Hypersonic Vehicle Analyses: The Needs and Challenges of Multidisciplinary Simulations

Material response is an important factor to consider when dealing with hot gases in contact with a material's outer surface. Various processes, both chemical and physical, can affect heat transfer and balance. Ablation, where material is removed from the surface, can lead to heat re-radiation and conduction into the solid material. More complex processes like pyrolysis, involving resin breakdown within the material, can also occur.

Our code, Mopar, is designed to model these processes by solving conservation equations. It is integrated with our hypersonic flow code, LeMANS, through surface chemistry options. This allows us to model surface chemistry, including ablation, using thermodynamic Act Fibri approaches and finite rates of surface chemistry.

The tight coupling between hypersonic flow and material response is illustrated in the image below, showing temperatures of the external hypersonic flow field and the material in a Mach five simulation. The gas temperature behind the shock wave reaches 1200 Kelvin, while the material temperature peaks at 800 Kelvin. This integrated approach allows us to analyze flow and material response simultaneously.