Modelling and simulation of liquid metal two-phase flows
Liquid metal two-phase flows are widely encountered in many industrial processes, such as power engineering, metallurgical and environmental engineering. The safety and efficiency in these industrial applications could be significantly improved by the adequate understanding of the fluid dynamics in liquid metal two-phase flow. However, compared to the air-water system, the opaqueness of the liquid metal makes the traditional measurement techniques such as high speed photography, PIV and LDV impossible. Thus, the experimental and numerical studies dealing with two-phase flows in liquid metal are relatively scarce compared to the numerous studies in transparent liquid, especially in water. However, studies on two-phase flows in liquid metal are substantially important and indispensable because of the significant differences on liquid properties compared to water, in particular the high density and surface tension. From the simulation side, the Euler-Euler two-phase models, in which all of the sub models are developed within the frame of air-water two-phase system, so far, still lack detailed validation in liquid metal two-phase flows due to limited available experimental data.
The general aim of this work is the qualification of the Euler-Euler approach for the simulation of liquid metal two-phase flows. The test section is a rectangular column and the argon was injected from a single needle distributed at the centre of the bottom plate into the column filled with liquid metal (GaInSn) resulting in an oscillating bubble plume. The experimental data for the validation is based on the project Liquid metal two-phase flows and magnetic particle separation. The oscillations caused by moving vortices result in a symmetrical flow structure after long-time averaging (see Fig. 1 and Fig. 2). The peak of time-averaged gas void fraction and vertical liquid velocity are located in the centre (See Fig.1 and Fig.2). A gross circulation flow with upward flow in the centre and downward flow along the walls prevails in the liquid phase (see Fig. 2). Overall, the results predicted by the Baseline model are in a quite good agreement with experimental data (see Fig.1 and Fig. 3). Future work would be performed considering higher gas void fraction and homogenous flow pattern.
This work is financially funded by China Scholarship Council.