CFD simulation of transient boiling regime for overheated water and nanofluids
Strativnov E.1, Nie Gunochao2.
1 Department of Thermo-chemical Processes and Nanotechnologies,
Gas Institute of the NAS of Ukraine. 
Degtyarivska, 39, Kyiv-03113, Ukraine. 
E-mail: estrativnov@gmail.com
2 School of Physics and Telecommunication Engineering, Yulin Normal University, Yulin 537000, China.

In this paper, we consider the transient mode (its CFD simulation) when hot body are cooling by liquid and nanofluids, an experiment on which was carried out by colleagues from Cambridge and described in article. The following goals were pursued in the work: 1 - Identification of decisive factors affecting the nature of boiling and the transition regime (temperature-dependent properties of water, steam and solid. 2 - Modeling nanofluids by adjusting the water properties according to the empirical formulas. 3 - Simulation as accurately as possible the phase transition process when cooling a smooth and rough heated body using the water and nanofluids. 4 - Description of technical issues related to the modeling process in ANSYS (Fluent) such as: features of building a grid model for solving non-stationary problems with a phase interface, selection and adjustment of models of boiling, turbulence, the mechanism of phase transformations, surface tension e.t.c.

a)                    b)                            c)
Fig. 1. a) - Mash; b) - Calculation domain; c) - Cooling graphs for DW, TiO2 based nanofluid and DW with nanostructured surfaces (roughness 1e-8).

These graphs correlate well with the data obtained experimentally. They have a very similar shape and slope, which indicates the correct operation of the calculation model.