Thermal instability of two-dimensional stagnation-point boundary layers

Abstract

A study of thermal instability for the two-dimensional stagnation flow for Prandtl numbers ranging from 0.7 to infinity is presented. The analysis represents an exact solution since neither the boundary-layer approximation nor the parallel-flow assumption was invoked. Of particular interest is that the critical Rayleigh number and the critical wavenumber, when defined on the basis of the thermal boundary-layer lengthscale, are found to be relatively insensitive to the Prandtl number for the range of Prandtl numbers studied.