A three-dimensional numerical study is performed to explore the effect of a pulsed rectangular heating element (also denoted as thermal bump) in a Mach 1.5 laminar flat plate boundary layer. The thermal bump is modeled as a time-dependent step surface temperature rise. The thermal bump generates a series of counter-rotating streamwise vortices formed at the four edges of the element. When the bump is pulsed, vortex shedding is observed. These vortices interact with each other, generating a complicated vortical field, and grow in the spanwise direction with the downstream distance. Results show that the vertical perturbation velocity plays a key role in generating a lifting effect to sustain the horizontal disturbances. The streamwise velocity perturbation produces a low-speed region downstream of the centerline and a high-speed region on each side of the bump. The disturbance energy shows that the streamwise kinetic disturbance energy dominates over other components.
Effect of Thermal Bump in Supersonic Flow Control
Published Online: March 01, 2011