An unsteady laminar boundary layer with separation and reattachment
Abstract
The equations for a twodimensional laminar boundary layer without spin are considered, and the question investigated is whether solutions without a singularity exist after the instant of time when a flow reversal occurs. For a given form of the external velocity field, the equations are solved by Keller's efficient and accurate box method with the aid of the program of Cebeci and Carr (1978) with a zigzag procedure incorporated into it. The local skinfriction coefficient and corresponding displacement thickness were calculated for different values of time, and the solution was found to remain smooth even when the region of reversed flow occupies the majority of the boundary layer. There is no hint of a singularity, and it is concluded that the original equations cannot develop a singularity at a finite time if the solution is free of singularities at earlier times.
 Publication:

AIAA Journal
 Pub Date:
 December 1978
 DOI:
 10.2514/3.61047
 Bibcode:
 1978AIAAJ..16.1305C
 Keywords:

 Boundary Layer Separation;
 Laminar Boundary Layer;
 Reattached Flow;
 Reversed Flow;
 Unsteady Flow;
 Coefficient Of Friction;
 Singularity (Mathematics);
 Skin Friction;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer