Drag reduction research in supersonic flow with opposing jet

A CFD study on drag reduction in supersonic flow with opposing jet has been conducted. Flowfield parameters, reattachment point position and surface pressure distributions are obtained and validated with experiments. From the analysis on the physical mechanism of drag reduction, it shows the phenomenon that, when the opposing jet blows, the high pressure region is located between the bow shock wave and the Mach disk, which makes the nose region much lower pressure. As the pressure ratio increases, the high pressure region is gradually pushed away from the surface. Larger the total pressure ratio is, the lower of the drag coefficient is. To study the effect of the intensity of opposing jet more reasonably, a new parameter R-PA has been introduced by combining the flux and the total pressure ratio. The study shows that the same shock wave position and drag coefficient can be obtained with the same R-PA with different fluxes and the total pressures, which means the new parameter could stand for the intensity of opposing jet and could be used to analyze the influence of opposing jet on flow field and aerodynamic force. (C) 2013 IAA. Published by Elsevier Ltd. All rights reserved.