Boundary Layer Equations and Boundary Conditions for Them in the Case of Motion in a Slightly Rarefied Gas with Supersonic Speeds

摘要

By using Prandtl's boundary-layer theory, equations are derived for a moderately rarefied gas which differ from the ordinary Prandtl equations by the presence of supplementary terms that contain higher derivatives of velocity and temperature; in the equations derived, the normal pressure gradient differs from zero and is expressed by supplementary terms. The boundary conditions for these equations are found with the aid of kinetic theory; they are a generalization of Maxwell's and Smoluchowski's conditions for motion at a supersonic velocity. The velocity and height limits of applicability of the equations derived are set forth. (Author)