Experimental study of transient forced turbulent separation and reattachment on a bevelled trailing edge

The purpose of this experimental study is to analyze the transient processes of the separation and reattachment of a turbulent boundary layer at the trailing edge of a splitter plate. The separation is driven by a steady pneumatic injection, considered here as an actuator controlling the mixing layer. Particle image velocimetry and hot-film measurements are performed at various stages of the processes. The results highlight the behavior of each transient. Analysis of the time scale of the processes is realized by means of bi-orthogonal decomposition. This gives essential information (e.g., time scale, qualitative features) for future applications using duty cycle mode to excite instabilities of the mixing layer.