Analytical Method of Prediction of Turbulent Boundary-Layer Separation in Hypersonic Flows

An analytical method of prediction of turbulent boundary-layer separation in hypersonic flows is presented. The boundary layer is associated with a flat plate for simplicity and is recognized as a fully turbulent boundary layer with a sufficiently high Reynolds number. A separated boundary layer has recirculating flow. The moment of separation can be more easily visualized by looking at velocity profiles within the boundary layer as it is subjected to greater pressure gradients. The velocity gradient at the wall will be zero, and the momentum flux out of the control volume will be approaching zero at the point of incipient separation. The shear stress at the wall cannot be estimated using the seventh power law, since it is not valid in the laminar sublayer. A possible reason for the independence on Reynolds number could be the assumption that the distance over which separation occurs is short and the shear stress can therefore be neglected.