A CFD Based Correlation for Erosion Factor for Long-Radius Elbows and Bends

Abstract

A model for predicting sand erosion in 90 degree elbows and bends has been developed based on computational fluid dynamics (CFD), particle tracking and erosion data. After the flow field was obtained from the flow (CFD) model, particles were introduced into the flow and particle trajectories were computed using a Lagrangian approach. A model was also implemented that accounts for the interaction between the particles and the target material. Based on predicted particle impingement velocities, erosion rates and penetration rates were predicted using the empirical equations for erosion ratio. The predicted penetration rates are compared with available experimental data for several different elbows. The agreement between the predicted penetration rates and the experimental data is good. In addition, based on many predictions and erosion rate results, a new CFD based correlation is developed that can be used for an approximate engineering calculation to account for effects of elbow radius on erosion in long-radius elbows. This equation is for computing the ratio of the wall thickness loss (or the penetration rate) in a long-radius elbow to the penetration rate of a standard (short-radius) elbow. The results from the correlation agree well with the trend of available data in the literature.

Numerical and experimental investigation of the relative erosion severity between plugged tees and elbows in dilute gas/solid two-phase flow

“…Elbows, that are an integral part of piping systems, are vulnerable in erosive environments. Wang's study [1] shows that increasing the elbow radius is an effective way to reduce the sand erosion damage. When it is unfeasible to use a long radius elbow due to space considerations, plugged tees are usually put in service rather than standard elbows to reduce erosion.…”

Effect of Bend Radius on Magnitude and Location of Erosion in S-Bend

“…Wang and Shirazi investigated the effect of elbows with different radii on erosion and reported that the long radius bend with / > 1.5 (where is the elbow curvature radius and is the diameter of pipe) has smaller impingement angles than short radius bend [7]. The study also reported lower erosion when a long radius elbow is used compared to 2 Modelling and Simulation in Engineering a standard elbow ( / = 1.5) for the same flow condition.…”

“…The effect of / ratio of different bends on erosion was reported in one previous study by Wang and Shirazi [7]. The current study was conducted to understand the effect of / on magnitude and location of erosion in S-bend geometry using CFD.…”

Numerical investigation of the process and flow erosion of flushing oil tank with nitrogen

“…close-up view where A f is projected area of particles in the wall, ṁ s is the particle mass flow rate represented by each computational particle that collides with face, N sd is number of particles, e r is the erosion ratio [6,7], K is a material-dependent constant, which has taken the value 2.17 × 10 −7 for carbon steel [6,30], n is an empirical coefficient taken as 2.41 [31], F s is the particle sharpness factor, F s = 0.2 is used since spherical particles are assumed in this study [6,7], f(α) is the angle function, K i for i = 1-5 are empirical constants, equal to − 0.334, 0.179, 0.01239, −0.01192 and 0.02167, respectively [32].…”