From Coils to Surface Recession: Fully Coupled Simulation of Ablation in ICP Wind Tunnels

TL;DR

This paper introduces a comprehensive multiphysics simulation framework for accurately predicting material response and ablation in ICP wind tunnels, integrating plasma physics, electromagnetic effects, and material thermochemistry.

Contribution

It presents a novel fully coupled computational approach that models plasma generation, electromagnetic heating, and material ablation in ICP environments from first principles.

Findings

Predicted heat fluxes match experimental data within uncertainty.

Recession rates are predicted with errors below 10%.

The model captures key ICP physics like vortex recirculation and plasma formation.

Abstract

This work presents a fully coupled, multiphysics computational framework for predicting the thermo-chemical material response of thermal protection systems in inductively coupled plasma (ICP) wind tunnels. The framework integrates a high-fidelity Navier-Stokes plasma solver, an electromagnetic field solver, and a discontinuous-Galerkin material response solver using a partitioned coupling strategy. This enables an ab initio, end-to-end simulation of the 350 kW Plasmatron X facility at the University of Illinois Urbana-Champaign (UIUC), including plasma generation, electromagnetic heating, near-wall thermochemistry, and time-accurate material ablation. The model captures key ICP physics such as vortex-mode recirculation, Joule-heating-driven plasma formation, and Lorentz-force-induced flow confinement, and accurately predicts the transition from subsonic to supersonic jet behavior at low pressures. Validation against cold-wall calorimetry and graphite ablation experiments shows that predicted stagnation-point heat fluxes fall well within experimental uncertainty, while fully coupled simulations accurately reproduce measured stagnation temperature histories and recession rates with errors below 12% and 10%, respectively. Remaining discrepancies during early transient heating are attributed to uncertainties in power-coupling efficiency, equilibrium ablation modeling, and material property datasets. Overall, the framework demonstrates strong predictive capability for ICP wind tunnel environments and provides a foundation for improved design, interpretation, and planning of hypersonic material testing campaigns.