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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

A SEMI-ANALYTICAL MODEL OF BUBBLE GROWTH AND DETACHMENT DURING NUCLEATE BOILING

Get access (open in a dialog) DOI: 10.1615/IHTC16.bae.023319
pages 935-942

Аннотация

The prediction of boiling heat transfer phenomena is an important issue in many technological applications, particularly in conventional and alternative energy conversion technology and cooling of electronic devices. Advanced computational models of nucleate boiling heat transfer, broadly based on Computational Fluid Dynamics (CFD) techniques, partition the heat flux at the wall into components due to liquid convection, transient conduction and evaporation. The latter component represents the transfer of latent heat from wall to fluid due to the growth and detachment of vapour bubbles. This component is usually modelled via semiempirical, semi-mechanistic treatments that require as input appropriate estimates of the bubble departure size. The accuracy of CFD models of boiling is particularly sensitive to the evaporation component submodel, hence the need of accurate estimates of the bubble size at departure. In this work, we assess the accuracy of a semi-analytical model of bubble growth, based on equilibrium thermodynamics, for a typical nucleate boiling model problem. Comparison between modelled and measured bubble growth and detachment is presented, as well as between predictions of the present model, and of Direct Numerical Simulations with Interface Tracking. It is shown that the model can reproduce correctly the observed mechanism of bubble growth, with accuracy similar to that of the Interface Tracking simulations.