Chemical-Kinetic Parameters of Hyperbolic Earth Entry

Abstract

Chemical-kinetic parameters governing the e ow in the shock layer over a heat shield of a blunt body entering Earth’ s atmosphere from a hyperbolic orbit are derived. By the use of the assumption that the heat shield is made of carbon phenolic and by allowing for an arbitrary rateof pyrolysis-gasinjection, chemical reactions occurring in the shock layer are postulated, and the collision integrals governing the transport properties, the rate coefe cients of the reactions, and the parameters needed for the bifurcation model and for the e nite-rate kinetic wall boundary conditions are determined using the best available techniques. Sample e owe eld calculations are performed using this set of parameters to show that the heating and surface removal rates are substantially smaller than calculated using theexisting setofsuch parameters and traditionalassumptionsof gas ‐surfaceequilibrium and quasi-steadystate ablation.