Enhancement of Impinging Jet Heat Transfer Using Two Parallel Confining Plates Mounted near Rectangular Nozzle Exit

Impinging jet heat transfer on a target plate was enhanced by using two parallel confiningplates mounted between a rectangular nozzle end plate and a jet target plate. The targetplate was set equal to 2, 3, 4, and 5 times the jet exit width, h, and the gap ratio of two parallel confining plates, W/h, were changed from 2.7 to 8.0 only by impinging length H=5h and from 2.7 to 6.7 by H≠5h. Two confining parallel plates mounted near the jet exit producedswing-type flow under some conditions. As a result, the maximum Nusselt numberattained around the stagnation point was augmented by about 50% compared to the onefor normal impinging jet without the two parallel plates and then spatial mean Nusseltnumber was increased by about 40%