Control of Separation Bubble on a Blade Leading Edge by a Stationary Bar Wake
This paper describes an attempt to suppress a blade leading edge separation bubble by utilizing a stationary bar wake. This study aims at exploration of a possibility for reducing the aerodynamic loss due to blade boundary layer that is accompanied with the separation bubble. The test model used in this study consists of semi-circular leading edge and two parallel flat plates. It can be tilted against the inlet flow so as to change the characteristics of the separation bubble. Detailed flow measurements over the test model are conducted using a single hot-wire probe. Emphasis in this study is placed on the effect of bar shifting or bar clocking across the inlet flow in order to see how the bar-wake position with respect to the test model affects the separation bubble as well as aerodynamic loss generated within the boundary layer. The present study reveals a loss reduction through the separation bubble control using a properly clocked bar wake.