On Mixture Model Application in Numerical Modeling of Boiling Phenomena Alen Cukrov 1 , Željko Tuković 2 , Bojan Ničeno 3 , Ivanka Boras 1 , Antun Galović 1 1 Department of Thermal and Process Engineering, University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, 10000 Zagreb, Croatia 2 Department of Energy, Power Engineering and Environment, University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, 10000 Zagreb, Croatia 3 Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland acukrov@fsb.hr ABSTRACT In this paper, a description of the multiphase modeling approach known as mixture model, or drift-flux model, is given. The mixture model is based on conservation equations for mass, momentum and energy of a mixture of all phases present in the flow. The individual phases are assumed to be in equilibrium over small distances of space, computational cells in practical terms. In order to account for different velocities each phase in reality has, the drift velocity of the dispersed phase is introduced and solved with algebraic set of equations based on empirical data. The mixture model described in this work will be used for boiling simulations, with quenching as the final application. Therefore, the fluids of interest are water and vapour, and the model should be capable to cover a range of boiling regimes. The results of a literature survey will be used to assess the relative advantages and shortcomings of the mixture model for simulations of boiling during quenching. The steps regarding future work are given. KEY WORDS Multiphase flow modeling, Heat transfer, Phase change. 1. INTRODUCTION The boiling phenomenon is of great interest in engineering practice, especially in the area of cooling due to high amount of heat which could be removed by such process. This phenomenon is followed with the complex mathematical models that, among others, require significant computational resources and time. However, for application of a certain computational method