Effect of conjugation on jet impingement boiling heat transfer

Boiling involves significant bubble induced flow mixing and phase change which give rise to a phenomenal heat transfer rate. The jet impingement produces a strong convection and influences the nucleate boiling heat transfer and burn-out characteristics. Experimental studies on jet impingement boiling heat transfer have been conducted, whereas only limited numerical simulations have been reported. In the current study, three jet impingement configurations are studied with a numerical approach in which the Rensselaer Polytechnic Institute (RPI) boiling model is applied. The simulation results agree well with the reported experimental data. The RPI boiling model is able to simulate the subcooled jet impingement boiling heat transfer in submerged and confined configurations. Finally, the effect of conjugation on jet impingement boiling heat transfer is investigated. The conjugation makes a great difference in this case. The results suggest that the data obtained in the experiments with the different heating schemes (thick copper block or thin-film heater, corresponding to with or without conjugation), although the jet parameters are same, can be significantly different and incomparable. Attention should be paid on heating scheme in the experimental and numerical studies. (C) 2015 Elsevier Ltd. All rights reserved.