A single circular synthetic jet issued into turbulent boundary layer
An experimental investigation has been undertaken to study the behaviour of a single circular synthetic jet issued into turbulent boundary layer produced on a flat plate in cross flow. At the given free-stream conditions, the jet is also issued into laminar boundary layer so that an effective evaluation on the interaction of the vortices with the changing boundary layer could be made. The flow visualization technique is used in conjunction with the stereoscopic imaging system to reveal a unique quasi three-dimensional recognition of the vortices formed in either type of boundary layer under varying synthetic jet actuator (SJA) operating conditions. Firstly, the laminar boundary layer is produced on the flat plate with zero pressure gradient and later on the same boundary layer is triggered to turbulence using a trigger device. The free-stream conditions are justified by PIV measurements, in that the velocity profiles are drawn at given streamwise locations for both laminar and turbulent boundary layers. The parametric map is given to identify and bound the SJA operating parameters to produce the explicit vortical structures at the given conditions.
synthetic jet actuator streamwise vortices wall shear tilted vortex rings