RELATIONSHIP BETWEEN THE RECOVERY FACTOR AND THE VISCOUS DISSIPATION IN A CONFINED, IMPINGING, CIRCULAR JET OF HIGH-PRANDTL NUMBER LIQUID

The radial distribution of the recovery factor for a confined impingin g jet of high-Prandtl number liquid is investigated by numerical appro ach with emphasis on its physical mechanism. The recovery factor is de termined by the viscous dissipation and Prandtl number. Unlike the cas e of the gas jet impingement, the recovery factor in the region close to the stagnation point can be much larger than unity, while the recov ery factor at the stagnation point approaches zero. The dependence of the recovery factor on the nozzle exit velocity profile, the jet Reyno lds number, and the nozzle-to-plate spacing is examined. (C) 1997 by E lsevier Science Inc.