Numerical simulation of water and sediment flow characteristics in tunnels based on Euler–Euler three-phase flow

Abstract

Knowledge of water and sediment flow characteristics in tunnels is essential for structural safety and post-disaster rescue operations. In this research, we developed a numerical model based on the Euler–Euler approach to simulate the three-phase flow of air, water, and sediment, aiming to predict the spatiotemporal flow characteristics in tunnels following the inrush. The model assumes that air, water, and sediment constitute a continuous medium through each other. The interaction drag between phases was taken into account. A standard k-ε turbulence model was used to simulate the irregular fluid flow. The spatiotemporal fluid behavior within the tunnel was investigated by analyzing the volume fraction, fluid velocity, and fluid pressure. In addition, the effects of the support condition, the machinery obstruction, and the curve radius on the three-phase flow characteristics were discussed. Numerical simulation results indicate that in the spatial dimension, the volume fractions, velocity, and pressure all display gradient distribution; in the temporal dimension, these three parameters all show phased features. Moreover, fluid behavior is greatly influenced by the support condition, the machinery obstruction, and the curve radius. The results establish a fundamental basis for additional investigations concerning spatiotemporal characteristics prediction of water and sediment inrush.