Boundary layer separation singularities for an upstream moving wall

The possible singular structure of a steady boundary layer at separation for a regularly prescribed outer flow and an upstream moving wall is examined. By means of a family of similar solutions, it is shown that a consistent description can indeed accommodate the flattening of the velocity profile at flow reversal postulated in the model of separation proposed by Moore et al. (1958). The conditions in the separated region downstream, being unknown, are reflected in the non-uniqueness of the expansion.