Flow Structures and Heating Augmentation Around Finite-Width Cavity in Hypersonic Flow

Abstract

Cavities significantly affect the heating of bodies in hypersonic flows. Previous studies have shown that boundary-layer flows can enter the interior of shallow cavities and augment heating. In this study, the three-dimensional flow structure induced by a finite-width rectangular cavity was revealed in compressible Navier–Stokes simulations. A finite-width rectangular cavity was found to encourage downwash into the cavity, and a pair of counter-rotating longitudinal vortices was established in the wake region of the cavity. The downwash draws high-speed boundary-layer flow into the cavity and augments the heating on the cavity floor. The high-speed flow impinges on the cavity endwall and causes local peak heating. Slowly dissipating longitudinal vortices are produced that generate long streaky hot regions in the wake. The heating augmentation induced by deep or narrow cavities is less than in shallow and wide cavities owing to the insignificant amount of high-speed flow entering the cavity.