Convection de la chaleur dans un gaz en régime laminaire dans le cas d'un gradient de pression et d'une température de paroi quelconques

Abstract

A new transformation, generalizing Illingworth-Stewartson's, transforms the compressible laminar boundary layer equations to the incompressible boundary layer equations, for any external velocity and wall temperature distributions. For this, a reference enthalpy, generalizing Monaghan's formula, is employed; pressure gradient terms are neglected in the transformed equations. Comparison between results obtained thus and those obtained by Cohen and Reshotko by integrating the full equations shows that the velocity and temperature profiles are almost identical, at least when the wall temperature lies between half and twice the stagnation temperature. When the wall temperature decreases, the error rises while staying below 7.3 per cent, for example, in computing the heat transfer coefficient at a two-dimensional stagnation point with the gas Prandtl number equal to 1. When the wall temperature of an arbitrary body is small compared with the stagnation temperature, the heat-transfer rate at the wall is given by a formula differing slightly from that of Lees.