Ablation-Radiation Coupling Modelling for Hayabusa Re-entry Vehicle

Reentry vehicles undergo extreme thermal conditions as they reach hypersonic velocities in particular conditions. Thus thermal protection system (TPS) are required to prevent the probe to be damaged. When it comes to Earth’s reentry, capsules like Hayabusa are equipped with an carbon phenolic TPS which ablates and releases ablation products into the boundary layer during reentry. Besides, as radiation can be a significant component of the overall heat load, chemical reactions may occur between the radiators and the ablative injected species so that the whole aerothermodynamic state is modified. Therefore, an accurate numerical modeling of the thermal, physical and chemical processes induced by hypersonic reentry , is needed. It implies to couple the fluid solver and the material response code thanks to a partitioned coupling algorithm. As for Hayabusa’s reentry simulations performed for the ARC project, ablation-flowfield and radiation-flowfield resulted to be accurate as they were compared to flight data or empirical correlations. Next step of ablation-radiation coupling consists in experimental tests in plasma wind tunnels and full coupling algorithm.