Numerical investigation of a Coandă Based Fluidic Vectoring System for Compressor Air Tip Injection

The operating range of compressors is limited by the outbreak of flow instabilities with a highly negative impact on performance. Active control such as air tip injection delays the onset of stall. Previous research [1] indicates that optimal performance is achieved when the air injection is tangential to the casing with a relative blowing yaw angle closely matching the blade stagger angle. As the relative blowing yaw angle changes with the operating point, the study focuses on the development of a device which can adjust its blowing angle using two co-flow jets and the Coandă effect. An extensive numerical parametric study is conducted involving various geometries. To fasten and ease the meshing process, a mesh adaptation technique is employed. A first bi-dimensional case is examined to validate the method on a Coandă-based co-flow jet vectorization. Subsequently, a three dimensional actuator geometry is analysed, accounting the constraints of a compressor. A validation of the method on the bi-dimensional case is presented and the effect of massflow ratios and radius of curvature are examined. Numerical results on the actuator geometry demonstrate the ability of the actuator to deflect a jet with an angle up to 15 degrees, while staying attached to the casing.