Analytical Investigations Of Equilibrium And Nonequilibrium Compressible Turbulent Boundary Layers

Analytical Investigations of Equilibrium and Nonequilibrium Compressible Turbulent Boundary Layers

An integral method is presented for the adiabatic compressible turbulent boundary layer which extends recent concepts of turbulent equilibrium boundary layers to the study of nonequilibrium flows. Coles' law of the wall and wake is extended to the case of compressible adiabatic flows with pressure gradient by employing Van Driest's generalized velocities. An analytical expression for the compressible turbulent equilibrium dissipation integral is then derived from the integral momentum, mean energy and local skin friction equations. For the general case of nonequilibrium flows with arbitrary pressure gradients, the dissipation integral is 'unhooked' from the equilibrium pressure gradient parameter through the use of a single empirical curve of existing incompressible flow data. Numerical solutions are then presented for a variety of compressible flows. As a first step in developing an integral method for nonadiabatic flows, the family of incompressible equilibrium enthalpy profiles are solved for from the thermal energy equation. (Author).

Technical Report DYN

NASA Technical Note