Flow Structures in a Compressible Elliptical Cavity Flow

This experimental and numerical study determines the time-averaged flow patterns within an elliptical cavity at a freestream Mach number of 0.83. The elliptical cavity model has a length-to-depth ratio of 4.43, which is classified as an open cavity flow. The flow within the elliptical cavity exhibits distinctive features due to its unique geometry. A large clockwise-rotating recirculation vortex is created, which is a common feature of an open cavity flow. Tornado-like vortices are observed at positions farther from the centerline than those in a rectangular cavity because of the geometric effect of the diverging sidewalls in the front half of an elliptical cavity, which increases the spanwise motion by directing internal flow from the centerline towards the sidewalls. Additional vortex structures, such as a front corner vortex, a rear corner vortex and secondary tornado-like vortices near the sidewalls, are identified. These structures contribute to complex flow interactions, including vortex–vortex, vortex–wall, and shear layer interactions. The three-dimensional effect affects the cellular structures within the cavity, which is similar to the effect for a rectangular cavity with a large length-to-width ratio.