Verification Study of CFD Prediction Accuracy of Liquid Droplet Impingement Erosion Rate for Engineering Applications

Abstract

Multi-phase flows containing liquid droplets widely exist in piping system of process plants. Sudden geometry change like elbow causes the flow turbulence, which leads to droplet impingement against the piping wall. As a result, erosion can be induced, and hence, may cause leak of piping. Therefore, it is essential to evaluate erosion rate for determining design margin and finding countermeasures for erosion-related trouble. Some models have been proposed for predicting droplet-induced erosion rate, but there is large difference in their prediction accuracy. The present study aims at verifying prediction accuracy of some major erosion models for engineering applications. CFD simulations of water jets are conducted to verify the prediction accuracy of erosion induced by liquid droplets, using the published experimental data. In the present simulations, a two-way approach is applied for solving the air-water two-phase flow. An original algorithm is used to calculate the droplet-induced erosion rate using the obtained two-phase flow fields. The investigated erosion models include the models of Haugen, DNV and Isomoto. CFD results show that almost all the investigated erosion models for various simulation conditions provide the conservative evaluation of erosion rates, compared with the experimental results. Among them, the erosion rates predicted by Haugen model are closest to the experimental results with acceptable prediction accuracy for engineering applications.