NUMERICAL STUDY OF RECOVERY EFFECT AND IMPINGEMENT HEAT-TRANSFER WITHSUBMERGED CIRCULAR JETS OF LARGE PRANDTL NUMBER LIQUID

A numerical study was conducted to characterize the thermal behavior o f laminar circular liquid jets. The main goal of this work was to clar ify the significant recovery effect of large Prandtl number liquid jet s reported by the present authors. Radial distribution of local recove ry factor was studied in numerical detail. The effects of many factors were investigated including Reynolds number, Prandtl number, nozzle-t o-plate spacing, jet velocity, nozzle diameter and velocity profile at nozzle exit. Very large recovery factors over 20 were obtained with h igh Prandtl number fluid jets at medium velocity. The results exhibite d good agreement with the experimental data by the present authors, ve rifying the great significance of recovery effect with large Prandtl n umber liquid jets. (C) 1997 Elsevier Science Ltd.