Boundary Conditions for the Turbulent Mixing Layer Between Two Parallel Streams

Abstract

The boundary conditions of the boundary-layer problem between two parallel turbulent streams are investigated solving higher-order terms of the inner and outer boundary-layer expansion. It is shown that the assumption that the eddy viscosity is proportional to longitudinal distance x fails to yield the third boundary condition of the boundary-layer problem. In this paper this boundary condition has been derived based on the consideration that the eddy viscosity attains a constant value at large but finite distance. The result applies to compressible as well as incompressible flow.