Studies on Re-attaching Wall Jets

Re-attaching wall jets have diversified applications in fluidics, in aircraft and other industries. In the present study, the results of experimental investigations carried out on re-attaching wall jets to an offset parallel plane surface are presented and compared with the results for plane wall jets. Experimental series were carried out on a 1/4” nozzle at eight different offset ratios using three different jet inlet velocities. Measurements were made for re-attachment point, vortex center, jet velocity profile beyond the re-attachment point, the static pressure on the bottom wall and of shear stress. In the outer layer beyond the re-attachment point the flow behaved like a plane wall jet. The decay of maximal velocity and growth remained similar to that of a plane wall jet, only the log law, representing the velocity distribution in the inner layer, differed from that of a plane wall jet. The vortex center location was found to be proportional to the re-attaching distance. The experimental findings were compared with the results obtained from a proposed theoretical method of prediction.