Pressure Gradient Effects on Supersonic Boundary Layer Turbulence


Book Description

Measurements of mean flow profiles at several streamwise locations in a supersonic turbulent boundary layer growing under a continuous adverse pressure gradient are reported. Tests were performed at a freestream Mach number of 3, for an adiabatic wall, using two curved ramps designed to produce constant pressure gradient flows. The velocity profile data, when transformed to incompressible coordinates, are in good agreement with Coles universal 'wall-wake' velocity profile and they indicate that the boundary layer is in local equilibrium and essentially independent of upstream history. In addition, the Coles wake parameters and Clauser shape factors, characterizing the transformed profiles, are in accord with the results of low speed correlations of adverse pressure gradient flows. The turbulent transport terms were extracted from the mean flow field data and indicate that for a given ramp, the profile of turbulent shear stress normalized by the wall shear, versus distance from the surface, normalized by the local boundary thickness, is severely distored by the pressure gradient although it is apparently insensitive to local conditions.




Mixing of Supersonic Jets Including the Effects of Transvere Pressure Gradient Using Difference Methods


Book Description

The usual boundary-layer equations describing the steady-state mixing of parallel jets are supplemented by the momentum equation in the direction normal to the flow. This allows detailed computation of the flow field in the mixing region and simultaneous computation of the outer inviscid flow. An explicit and an implicit finite difference scheme have been developed and applied in several illustrative examples. The examples include mixing of planar and axisymmetric supersonic jets of different composition with both matched and unmatched static pressures. Numerical results were compared with available experimental data obtained for the unmatched pressure case.
















Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.