Influence of suction on the developing wall flow of an impinging jet

Attention is called to the paucity of information on the effects of applying moderate suction along the surface of the developing flows. The experiment described here derives from the need to obtain experimental information on the flowfield that would be of use in interpreting the role of suction on impingement heat transfer. Suction is found to create a larger volume of flow toward the impingement surface, to reduce the momentum boundary-layer thickness and the wall jet half-width, and to increase the velocity gradient near the surface and hence the wall shear stress. When the ratio of r to Z sub n is greater than or equal to 1.33, the dimensionless velocity profiles are independent of both suction velocity and radial location.