Control of Suddenly Expanded Flow with Cavity at Sonic Mach Number

This study focuses on the control of the pressure in the base corner as well as flow quality in the duct during a numerical simulation of sonic airflow from a convergent nozzle exhausted into the circular duct with annular rectangular cavities. Three variables were found to significantly affect the base pressure: expansion level, area ratio, and duct size. For a lower area ratio, the passive control with cavities increases the pressure in the wake corner. Wake pressure also depends critically on the geometry and dimension of the cavity. In this investigation, we took into account the flow and geometrical factors of nozzle pressure ratio (NPR), cavity aspect ratio (ASR), and cavity location (CL). At sonic Mach numbers with the sudden enhancement of the flow area, the computational fluid dynamics method employs flow from a convergent nozzle. The Mach number of the study was M = 1.0 and an exit area ratio of 2.25 was found between the duct and the nozzle. The duct length considered was L = (1D, 2D, 3D, 4D, and 6D), and NPRs considered (1.5, 2, 3, 4, and 5) were used for simulations. The ASR 1 cavities are annular rectangles, 3 mm wide and 3 mm high. The outcomes of the base pressure are compared for ASR 2 with dimensions of 3 mm in width and 6 mm in height. In this study, a turbulence model based on the K-standard wall function was used to simulate and examine the nozzle. The results demonstrate that pressure in wake was considerably inspired by NPR and the cavity positioning from the base.