A Preliminary Study on the Simulation of Vortex Flow in Pump Intake Based on LBM-VOF-LES Combined Model

Abstract

In this paper, the lattice Boltzmann method-large eddy simulation (LBM-LES) model was combined with the volume of fluid (VOF) method and used to simulate vortex flow in a typical pump intake. The strain rate tensor in the LES model is locally calculated utilizing nonequilibrium moments based on Chapman–Enskog expansion, and the bounce-back scheme is used for nonslip condition on the solid wall and VOF method for the free surface. The evolution of all kinds of cells on the free surface is based on the mass exchange in the VOF method, i.e., lattice Boltzmann-single phase (LB-SP) free surface model. The introduction of the external force terms is established through adding corresponding expressions on the right of the lattice Boltzmann equation (LBE), and by modifying the velocity. The predicted vortex flow patterns (core location and strength of the vortex) and velocity correlate with the experiments undertaken with the physical model. A comparison of the results demonstrates the feasibility and stability of the model and the numerical method in predicting vortex flows inside pump intakes. The model developed and presented in this paper provides a new analysis method of vortex flow patterns in pump intake from a mesoscopic perspective, enriches the relevant technologies, and makes corresponding contributions to further engineering applications.