RANS Predictions of Junction Flow with Localized Suction

Abstract

Horseshoe vortex is a prominent feature in junction flows which not only changes the local flow patterns but is also responsible for aerodynamic loses in the region. In the past many investigations using wind tunnels and CFD have been made to study the junction flow. These studies have shown that RANS prediction of the junction flow demonstrate an acceptable qualitative match with the experimental results. The present study extends the CFD investigations to RANS predictions of the junction flow with boundary layer control using localized suction. Localized suction is an active technique that has proved successful, in the past through wind tunnel measurements, in elimination of the junction horseshoe vortex. The present investigations used these experimental results to evaluate the RANS predictions from the current study. During the course of this study, six cases of junction flows with and without localized suction were numerically simulated and compared with the wind tunnel measurements. For no suction case CFD and experiment have been found in good agreement with similar patterns observed for the vortex core in the symmetry plane. When suction was applied, a similar reduction in the vortex core was predicted by CFD as observed in the wind tunnel. It was concluded that RANS have made fairly accurate predictions in almost all the cases in comparison with the experimental data.