PREDICTING STOCHASTIC FEATURES OF VAPOR BUBBLE DETACHMENT IN FLOW BOILING

The stochastic features of vapor bubble departure and lift-off diamete rs in forced convection boiling are considered in terms of probability density functions (pdfs). A mechanistic model is developed for the pr ediction of these functions. Their prediction requires a vapor bubble detachment model and pdfs of the mean wall superheat and mean liquid v elocity. The agreement with horizontal flow boiling vapor bubble depar ture and lift-off data is very good. To the best of the authors' knowl edge, this is the first attempt at developing such a predictive capabi lity. In order for the model to be generally applicable to flow boilin g systems, the assumptions used in estimating the mean wall superheat and mean vapor velocity pdfs require further scrutiny. (C) 1997 Elsevi er Science Ltd.