Multiphase coupling transport evolution mechanism of the free sink vortex

The sink vortex with a free surface exists some physical processes in the suction evolution process, such as multiphase coupling, mass transfer, and intensive energy exchange. Here, the transport mechanism of multiphase coupling is a complex dynamics problem with highly nonlinear characteristics. The mechanical modeling and numerical solution of multiphase viscous coupled transport face a significant challenge. To address the above problem, a multiphase coupling transport modeling-solving method of the free sink vortex is proposed. Based on the coupled level set and volume-of-fluid (CLSVOF) method, a multiphase coupling transport model of the free sink vortex is set up with a continuous surface tension model and a realizable (k-ε) turbulence model. An effective volumetric correction scheme calculates the high-speed rotating flow and ensures the mass conservation of flow fields and the velocity field without divergence. Then, an interphase coupling solution approach accurately traces the multiphase fluid distribution and multiphase interface. The multiphase coupling interface and cross-scale vortex cluster transport laws are obtained according to the multi-characteristic physical variables. The interaction mechanism between the multiphase coupling transport process and the pressure pulsation characteristics is revealed. The results show that the multiphase coupling transport is the critical state of the fluid medium transition. The vortex microclusters are subjected to different spatiotemporal disturbance modes and form the layered threaded waveforms at the interface. With the increment of the nozzle sizes, the multiphase coupling process enhances, and the coupling energy shock causes nonlinear pressure pulsation. It can offer valuable references to the research works of the vortex transport mechanism, cross-scale solution of vortex cluster, and flow pattern tracking.