Numerical Prediction of Solid Particle Erosion for Elbows Mounted in Series

Erosive wear due to solid-particle impact is a complex phenomenon where different parameters are responsible for causing material removal from the metal surface. Some of the most critical parameters regarding the solid particles are the size, density, roundness, and volume concentration. The properties of the carrying fluid (density, dynamic viscosity, bulk modulus…), the geometry of the flow path (straight or deviated), and the surface material properties are also major contributors to the overall severity of the solid-particle erosion process. The intent of this paper is to focus on the impact of the flow path geometry on surface erosion for a specific carrier fluid, flow rate, sand type and sand-volume concentration. A numerical approach using the commercial CFD code FLUENT is applied to investigate the solid particle erosion in two 90° pipe elbows mounted in series. The distance between the two elbows is varied, as is the angle between them. A total of 16 cases are analyzed numerically. The relationships between the parameters pertinent to the two elbows and the erosion pattern, erosion intensity, and location of maximum erosion are presented. Prior to the analyses for the two elbows mounted in series, an in-depth validation effort for a single elbow geometry is undertaken to determine the appropriate mesh requirement, turbulence model, and to calibrate the inputs to the erosion model.