Numerical computation of unsteady laminar boundary layers with separation using one-parameter integral method. II - The separation singularity in unsteady boundary layer

A recently proposed two-moment one-parameter integral method which is generally applicable even to unsteady boundary layers with reversed flows is improved. The functional relations of the shape parameters are improved using the velocity profiles of a rear stagnation flow in addition to the quartic and Falkner-Skan profiles. The computational scheme is also improved by applying the flux vector splitting method of Skeger and Warming (1981). It is confirmed that, the governing equation system being hyperbolic, a singular behavior of the unsteady boundary layer relevant to separation is reducible to the formation of a shock-like discontinuous solution via the coalescence of characteristics as conjectured by Shen (1978).