PREDICTION OF JET IMPINGEMENT HEAT-TRANSFER USING A HYBRID WALL TREATMENT WITH DIFFERENT TURBULENT PRANDTL NUMBER FUNCTIONS

The local heat transfer coefficient distribution on a square heat sour ce due to a normally impinging, axisymmetric, confined and submerged l iquid jet was computationally investigated. Numerical predictions were made for nozzle diameters of 3.18 and 6.35 mm at several nozzle-to-he at source spacings, with turbulent jet Reynolds numbers ranging from 8 500 to 13,000. The commercial finite-volume code FLUENT was used to so lve the thermal and flow fields using the standard high-Reynolds numbe r k-epsilon turbulence model. The converged solution obtained from the code was refined using a post-processing program that incorporated se veral near-wall models. The role of four alternative turbulent Prandtl number functions on the predicted heat transfer coefficients was inve stigated. The predicted heat transfer coefficients were compared with previously obtained experimental measurements. The predicted stagnatio n and average heat transfer coefficients agree with experiments to wit hin a maximum deviation of 16 and 20 percent, respectively. Reasons fo r the differences between the predicted and measured heat transfer coe fficients are discussed.