Heat Transfer Enhancement and Flow Resistance Reduction of Orifice Impinging Jet

Abstract

The effects of the contraction area ratio CR on impinging jet characteristics are studied. It is found that the smaller CR provides better heat transfer performance reflecting its centerline velocity increase. The smaller CR, however, needs a more operation power because of its large flow resistance. Then, we proposed a cone orifice nozzle to reduce the flow resistance of the nozzle and showed that the cone orifice nozzles of α=5 and 15° have enhanced heat transfer rates under the same operation power of the common orifice nozzle of α=0°.