Kinematic eddy viscosity at low Reynolds numbers.

Abstract

with A = A + v(tw/p)~]-/2, and showed that when Eqs. (3) (with a = 0.0168) and (5) were used as the eddy- viscosity formulation in the solution of the boundary-layer equations, the agreement with experiment was improved. Bushnell and Morris6 made measurements in hypersonic turbulent boundary layers at low Reynolds numbers. They observed that when they calculated the eddy-viscosity distribution from their data, the variations with Reynolds number of the parameters K and a in the inner and the outer eddy-viscosity formulas were similar to those in Refs. 5 and 4. Recently Huffman and Bradshaw7 concluded, after examining a large number of experimental data, that the parameter K in Eq. (5) was a constant. As may be seen from all these studies, the question of the universality of these constants is not settled. In the present Note we attempt to settle the question by showing that the parameter a is not a universal constant, but that K is— at least according to the calculations done by the author.