Studies On The Unsteady Boundary-Layer On A Flat-Plate Subjected To Incident Wakes - (Forced Transition Models Of The Boundary-Layer)

Detailed studies are conducted to investigate the effects of the incident wakes generated by rotating circular cylinders on the characteristics of the transitional boundary layer developing on a flat plate. In this report, the primary concern is to measure the time-averaged heat transfer distribution along the flat plate under several conditions of wake characteristics and cylinder speeds. The obtained data are then utilized in the development of a simple but accurate model for an intermittency factor of the transitional boundary layer subjected to the incoming wakes. Two transition models, the Mayle-Dullenkopf model and a geometrical intermittency factor model, i.e., a modified Pfeil model, are employed for comparison with the measured heat transfer data, and it is found that the latter model, which only considers evolution of the turbulent spot in the space-time domain, yields a better prediction.