Plasma surface interactions in hypersonic and atmospheric entry flows

Many challenges in the modeling and simulation of hypersonic and atmospheric entry flows are linked to plasma surface interactions. The effect of a plasma enveloping hypersonic vehicles on the propagation of electromagnetic waves and the charging of space platforms flying at very low Earth orbits are two examples of applications. The catalytic recombination of atoms at the wall as well as the chemical ablation of thermal protection materials, are phenomena to model accurately when developing the heat shield of atmospheric entry spacecraft. Other hypersonic applications are the signature of cruise vehicles, meteors, or the re-entry and destruction of artificial space debris.



We will review some of the current models used by the aerospace community for plasma surface interactions ane their limitations. Depending on the flow regime, these models can be coupled to kinetic equations solved by means of stochastic particle methods and fluid equations discretized using computational fluid dynamics methods. Finally, multiphysics solvers require the validation and calibration of plasma-surface interaction models. We have developed uncertainty quantification techniques for aerospace experiments carried out in the plasma facilities at the von Karman Institute for Fluid Dynamics. The Plasmatron facility is a 1.2MW inductively coupled plasma wind-tunnel allowing us to reproduce plasma surface interactions at the peak heating conditions of an atmospheric entry. The DRAG-ON facility is used to simulate the high-speed, low-density flow encountered by space platforms flying at very low Earth orbits.