Abstract
The present study investigates wake-induced bypass transition of boundary layers on a fiat plate subjected to favorable and adverse pressure gradients. The aim is to exploit unsteady effects in order to design a turbine blade without increasing the profile loss, as has been achieved for low pressure turbine blades. First of all, this fundamental study is to reveal the effect of wake passing frequency. Detailed boundary layer measurements were conducted using hot-wire probe. A passage-contouring device was employed to generate a pressure gradient on the test model, which was typical to that generated by a turbine blade. A wake generating squirrel cage was used to create periodic wakes in front of the flat plate. Computational fluid dynamics analyses are also applied to the flow field. It was found that the wake passage induces a temporary turbulence promoting in the flow over a flat plate surface.
