Eulerian Model For The Prediction Of Nucleate Boiling Of Refrigerant In Heat Exchangers
D. Sim´on, M. C. Paz, A. Eir´ıs & E. Su´arez
In this article, a boiling model for \“Fluent 6” fluid flow simulation software, for its use in gas-liquid heat exchangers, is presented. After a thorough study of existing bibliographies, a physical model has been compiled, which has been incorporated into the eulerian multiphase model, the most suitable of those available in Fluent for the resolution of these kinds of multiphase flows. Also discussed are some of the aspects of the implementation, which basically consist of the modeling of the interactions between phases as source terms in the governing equations solved by Fluent. Finally, the implementation of the model has been validated against experimental tests from the available literature, achieving a satisfactory degree of concordance. Keywords: CFD, heat exchangers, nucleate boiling, FLUENT, multiphase, eulerian. 1 Introduction The study of boiling is one of the requirements in the design stages. The experimental tests in this field are complex and very costly, which means that a computer tool is necessary to make quick and economical predictions. The boiling model presented in this paper is physically valid for the region of nucleate or sub-cooled boiling. The equations shown are based on local parameters in order to be applied to any geometry, having undertaken the necessary generalizations from the correlations, which were originally obtained in experimental tests. A modification of the Kurul and Podowski  model is employed, which has successfully been applied to diverse geometries by several authors.
CFD, heat exchangers, nucleate boiling, FLUENT, multiphase, eulerian