Investigation of Partially Catalytic Boundary Conditions for High-Speed Flows

Differences caused by noncatalytic vs. fully catalytic wall boundary conditions were assessed using CFD for a 2D-wedge model for a range of Mach numbers ([Formula: see text]) and altitudes ([Formula: see text]). For Mach numbers between 8.5 and 10, results showed measurable differences between noncatalytic and fully catalytic models on the integrated wall heating, independent of altitude, as high as [Formula: see text] for Mach 10 at an altitude of 45 km. Results for a partially catalytic model wall showed an exponential dependency of the wall heating due to the catalytic recombination coefficient of atomic oxygen, [Formula: see text], for the regime in question. As [Formula: see text] approaches one, a partially catalytic model exponentially approaches the fully catalytic model results. In addition to the corridor of potential application for a partially catalytic model, this study provides two important revelations: [Formula: see text] must be accurate [Formula: see text] to produce a distinguishable solution in between both extremes (non and fully catalytic) assumptions; and a fully catalytic model should be used in simulations in which [Formula: see text] are not known for all i-species expected to recombine since it provides the most conservative prediction of wall heating.