Session: Flow Visualization and Regular Poster Session

Paper Number: 158183

158183 - A Numerical Study of Sand Particle Erosion in Reducing Elbows 

Abstract: 

The phenomenon of erosion caused by sand particles in pipelines and fittings is a serious issue in the oil and gas industries. Due to their specific geometries, elbows are more prone to such damage. Therefore, it is crucial to predict and understand the physics of sand particle erosion in these components for regulating production rates, sizing lines and preventing costly failures. To this end, the computational fluid dynamics (CFD) coupled with the discrete phase model (DPM) can be utilized to investigate erosion rates for safety purposes and greater equipment longevity. While many studies have focused on gas-particle erosion in standard elbows, few studies are available that investigate this phenomenon in reducing elbows. Hence, this study focuses on the erosion behavior in these types of configurations to provide valuable information for maintenance and design engineers to minimize costs associated with erosion failures under varying operating conditions. In the present work, the CFD/DPM numerical method was employed to investigate the effects of key characteristics of gas, particles, and reducing elbow geometries on erosion rates and distributions. The SIMPLE method, along with the k-ω SST turbulence model, was utilized to simulate gas flow behavior in three different reducing elbow configurations: 3"×1.5", 3"×2" and 3"×2.5". The Lagrangian approach was then employed to track the particles and finally, the erosion rates were calculated based on the impact characteristics of particles with the wall. After comparing the results of several CFD setups for erosion and rebound models of particle-wall collision, the DNV erosion model coupled with the Forder rebound model was selected for the rest of the study, as it showed good agreement with the available experimental data in the literature. Erosion rates were evaluated for three particle sizes: 50, 150, and 300 microns, while the inlet gas velocity varied from 11 m/s to 27 m/s. The effects of Stokes number on erosion hotspots and particle behavior were also examined to capture changes in all relevant parameters. This investigation demonstrated that for higher Stokes numbers, all configurations experience larger erosion rates closer to the opening area of the elbows. In addition, reducing elbows with higher contraction ratios have greater sensitivity to gas velocity changes. Under the same conditions, while the erosion patterns are almost similar to those in standard elbows, due to the higher particle impact velocity, the maximum erosion rate for the 3"×1.5" elbow is 50% larger than that in the 3"×2.5" elbow at a gas velocity of 27 m/s.

Presenting Author: Ali Farokhipour Department of Mechanical Engineering, Amirkabir University of Technology

Presenting Author Biography: