Effect of Yaw on the Flow Asymmetry and Resonance Characteristics of a Rectangular Cavity at Mach 2

Three-dimensional cavities display instantaneous and mean patterns that are asymmetric about the centerline even near zero yaw. These take the form of one or more so-called tornado vortices with axes perpendicular to the cavity floor and preferred swirl orientations (clockwise or counterclockwise). They shift over time from one side of the symmetry plane to another in an unpredictable and relatively sudden fashion. The present study is an attempt to decipher the intricate flow structures and associated flow physics resulting in the onset, evolution, and establishment of asymmetric flow in a rectangular cavity (L/D = 4.5) at M∞ = 2. In addition, the cavity is yawed with respect to the incoming flow to study its effect on flow asymmetry and resonance characteristics of the cavity. The results show evidence of bi-stable contra-rotating vortical states inside the rectangular cavity at 0◦ yaw. Further, these vortical states take a preferred direction when the cavity is yawed away from the symmetry plane even by angles as low as 1◦, thereby highlighting the sensitive nature of the cavity flow to yaw angles