Analytical Model of Ablation Using Bimodal Velocity Distribution Function in Knudsen Layer

摘要

An analytical model of the Knudsen layer at ablative surfaces has been developed that takes into account thentemperature gradient in the bulk gas and rebound of gas particles by the ablative wall back into the gas region. Thisnmodel uses a bimodal velocity distribution function, which preserves the laws of conservation of mass, momentum,nand energy within the Knudsen layer and converges to the Chapman–Enskog velocity distribution function at thenouter boundary of the Knudsen layer. The region of validity of this model and effects of the temperature gradient,ndiffusive reflection, and specular reflection on the Knudsen layer properties are calculated.