Numerical analysis of solid–liquid flow and erosion characteristics during the opening and closing processes of ball valves

Valves are the key components used for flow control in the process industry, and solid–liquid two-phase flow is commonly encountered during valve regulation. Solid particles impact wall surfaces and cause continuous erosion, which undermines the stability and reliability of long-term operation. In this study, the discrete element method (DEM) was used to investigate the solid–liquid two-phase flow and flow-induced erosion characteristics inside a ball valve. Simulations were conducted for different dynamic processes (valve opening and closing) and particle diameters (50, 250, and 500 μm). Flow field results, including particle distributions and erosion rate distributions, were obtained and analyzed in detail. Two distinct erosion bands appeared on the rear wall inside the valve core, while two symmetric erosion peaks were observed on the interior wall of the downstream pipeline. The particle diameter significantly influenced the flow distributions and erosion characteristics in the valve, and the erosion was slightly more severe during the valve closing process than during the opening process. The results of this study can contribute to an in-depth understanding of the flow behavior and flow-induced damage during valve operation and can serve as an important reference for erosion resistance designs and valve applications.