Effect of streamwise vortices generated by a jet vortex generator on a characteristic scale of a turbulent shear layer with the diffuser separation

Experiments were conducted on a problem of interaction of streamwise vortices with a turbulent boundary layer and a mixing layer developing in a diffuser. Vortices were generated using jet vortex generators located near the front edge of the diffuser. The majority of measurements were conducted using hot-wire anemometry (HWA) and PIV methods. These experimental methods provide information about flow velocity in the preseparated and separated flow zones and about the dynamic pressure. This allowed for the estimating the turbulent structure scales and parameters of streamwise vortices for different operation regimes of vortex generators. It was observed that a flow with streamwise vortices has a smaller area of separation and this affects significantly the characteristic scale of turbulent structures.