Experimental study on the dryout heat flux of falling liquid film

A combined analytical and experimental investigation was carried out for the critical heat flux leading to dryout of falling liquid films. A modified model for predicting the dryout heat flux was correlated with the recent experimental results, with an average relative deviation of 12.7%, which is significantly less than that of previously reported ones. This improvement is believed to be the result of including the capillarity-induced interfacial evaporation [B.X. Wang, J.T. Zhang, X.F. Peng, Effects of interfacial evaporation on flow and heat transfer of thin falling liquid film, Science in China Ser. E, 1999, submitted] and the modification of streamwise thermocapillarity. The interfacial heat flux is showed to be important for heat transfer and for predicting dryout heat flux of falling liquid films. The new model indicates that, the bulk outlet temperature of falling film is required for accurate prediction of the critical heat flux leading to dryout. The results, compared with the current experimental results, demonstrate that the new model provides better predicted results in general.