Reattachment Length and Transition of the Separated Flow over Blunt Flat Plates

A visualization study has been conducted for the reattachment length and transition of the separated and reattached flow over blunt flat plates of finite thickness having various nose shapes over a Reynolds number range between about 40 and 2000. The reattachment length increases with an increase of the Reynolds number, reaches a maximum at a specific Reynolds number depending on the nose shape, and then decreases. The separated shear layer plays an important role on the characteristic variation of the reattachment length. Clarified is the transition Reynolds number at which the laminar separated shear layer exhibits an undulating motion before the reattachment point is reached.