Abstract

This study investigates the regulation of base flows in a duct with a sudden expansion at a supersonic Mach number. This study utilizes internal flow to simulate the flow area in the recirculation zone within a cavity. This work covers geometrical parameters, including an area ratio of 2.25 and an L/D ratio varying from 1 to 6. To control the base pressure, cavities with w/h ratios of 3:1 and 6:1, and the location of the cavities, were varied from L/D = 0.5 to 2. The inertia parameters considered are the expansion levels and Mach number M = 1.8. The cavity is employed as a flow control to regulate the base pressure and, consequently, the base drag. Based on the results, it is possible to improve the aerodynamic design to meet the design specifications. This work also provides the design process for a passive control in terms of the cavity for abruptly expanded flow in a nozzle with a supersonic flow Mach number design criteria. The cavity does not negatively affect the nature of the stream.

Keywords

passive control, base flow, Mach number, design Mach number, L/D ratio