Evaluation of Interface Capturing Schemes of VOF Method through Application to Bubble Flows with Single Orifice

Abstract

Mechanistic multi-phase fluid computations with the VOF method are becoming possible for the scale of engineering equipment in recent years. However, the performance of the interface capturing schemes (ICSs) on which these computations are founded are generally not well evaluated for the realistic multi-phase flow involved in engineering problems in user’s interest. This study, therefore, aims to evaluate the performance of the ICSs with growing popularity, the THINC and the THINC/WLIC, with the evaluation axes of the volume of bubbles which is of the great importance in the reactor physics and the nuclear thermalhydraulics. A single bubble rising and an experiment of bubble flow with single orifice is analyzed with the above two ICSs, followed by the qualitative and quantitative comparison. While the qualitative bubble flow pattern and the total bubble volume in the results with THINC schemes agree with that of the experiment, the simulation result with the THINC/WLIC scheme shows a significant numerical dissipation of the bubble volumes, an unphysically tiny bubbles and an unintended continuous gas injection. The cause of these numerical issues is identified as the slight numerical diffusion of VOF and its subsequent dispersion by the shear stress, which has not been clearly recognized by the preceding VOF advection tests.