Control of flow separation in S-ducts via flow injection and suction

Abstract

This work explores the use of injection and suction as a mean to control the separation of flow in S-duct inlets. The overall goal is to reduce the distortion of the S-duct outlet flow and to improve its pressure recovery by using the least expenditure of energy. We also aim to understand to what extent computational means can be practically useful for optimizing this flow-control method. Computations and experiments were used to study the effect of injection and suction of 2% on the main stream in an S-duct of M2129 geometry. The control flow can be recirculated with advantages in term of mass flow and energy management. The benefit of the method is assessed by contrasting controlled flows to corresponding baseline (no-control) flows over a range of subsonic inlet conditions. The experimental measurements substantially validate the results from computation and indicate that the method is highly effective in controlling the flow separation. Copyright © 2008 by Temasek Laboratories - National University of Singapore.