3D vortex structure and wall pressure distribution on a circular cylinder with jet impingement*

Jet impingement is a direct and efficient way to transfer heat and mass in various applications. In practical applications, most jet flows are impinging on curved surfaces, however, less attention has been given to circular jet impingements on convexly curved surfaces. Interactions of three-dimensional flow structures of a round jet impinging obliquely on a convex circular cylinder was studied using a large eddy simulation and 3D PIV measurements. Quantitative visualization of surface pressure was performed by PSP technique to verify the LES results and explain the Coanda effect on 3D wall jet flow along the cylinder wall. The strong shear layer near the impingement area makes small-scale vortices with high vorticity. These structures distribute throughout the surface and break down to multiple vortex structures with lower vorticity. Large-scale negative vortex structures are moved away from the wall jet and are sustained longer at the edge of the wall jet.