Laminar Reactive Boundary Layer Simulation of an Ablating Heated Carbon Surface

Abstract

Two-dimensional simulations were performed with applications to reactive boundary layers present over ablating surfaces. This work was performed in close coordination with experimentalists at the Air Force Institute of Technology (AFIT), where the simulations will be applied to the reactive boundary layer present on missile surfaces caused by laser induced ablation. Previously developed semi-global surface reaction models for both nonporous and porous carbon were used in a finite volume computational fluid dynamics (CFD) reacting flow solver. Detailed chemical kinetics, molecular transport and thermodynamic properties were implemented into the CFD code and the surface reaction was included as an external subroutine. A range of surface temperatures and free stream velocities were simulated using a 5 mm long reacting carbon plate. Results show that reaction layers and species present along the surface differ according to carbon surface porosity, surface temperature, and chemical residence time. These predicted structures expose what types of intricacies are to be expected in reacting boundary layers that will be investigated experimentally by AFIT.