Stabilization Mechanisms of Traveling Crossflow Mode in Hypersonic Swept Wing Flows

Momentum potential theory (MPT) is employed to establish a physics-based interpretation of the traveling crossflow mode and analyze the underlying stabilization mechanisms of associated control methods, such as wall cooling, wall suction, and grooves. The traveling crossflow mode over a swept wing with a Mach number of 6 is first solved using direct numerical simulations. The MPT decomposition illustrates the vortical nature of the traveling crossflow mode, with the vortical component having a higher magnitude than the acoustic and thermal components. The vortical source makes the greatest contribution to the mode instability, whereas the response of the source terms depends on the control method used. Wall cooling primarily impacts the thermal component, thus decreasing the thermal source and subsequently changing the vortical source. Wall suction influences the vortical component directly, and only the vortical source undergoes a small reduction. The acoustic and vortical components are sensitive to grooves. The compression waves induced by grooves are identified as the source of the stabilization effect.