Flow Characteristics Downstream of Swirl Flow Generators

An attempt was made, through experiments and numerical simulations, to clarify the mechanisms associated with the flow characteristics downstream of both inlet guide vanes (IGVs) with different vane geometries and circulation control wings (CCWs) with different jet sheet momentum coefficients. The novelty of the present study lies in the proposal of a swirl flow generator which can control the flow angle without changing geometrically. The main objectives were: (1) to revalidate the numerical analysis method employed in the present study, which was used to assess the flow characteristics downstream of the IGVs and (2) to suppress flow oscillations through tangential blowing. Characteristic flow patterns downstream of flat-plate vanes and circular cylinders with tangential blowing, with identical exit flow angles, are presented, and the unsteady flow characteristics downstream of the IGVs are compared with those of the CCWs. Furthermore, the influence of the radius ratio of the device outlet to the vane exit on the unsteady flow characteristics downstream of the IGVs and CCWs is discussed based on the measured pressure and velocity fluctuations.