Experimental study on the dryout heat flux of falling liquid film

A combined analytical and experimental investigation was carried out for th e critical heat flux leading to dryout of falling liquid films. A modified model for predicting the dryout heat flux was correlated with the recent ex perimental results, with an average relative deviation of 12.7%, which is s ignificantly less than that of previously reported ones. This improvement i s believed to be the result of including the capillarity-induced interfacia l evaporation [B.X. Wang, J.T. Zhang, X.F. Peng, Effects of interfacial eva poration on flow and heat transfer of thin falling liquid film, Science in China Ser. E, 1999, submitted] and the modification of streamwise thermocap illarity. The interfacial heat flux is showed to be important for heat tran sfer and for predicting dryout heat flux of falling liquid films. The new m odel indicates that, the bulk outlet temperature of falling film is require d for accurate prediction of the critical heat flux leading to dryout. The results, compared with the current experimental results, demonstrate that t he new model provides better predicted results in general. (C) 2000 Elsevie r Science Ltd. All rights reserved.