Multiphase Flow Analysis between Sand and Water in Horizontal Pipe and Bends

Abstract

The deposition of impurities in pipelines is very common in various pipeline system existing in different industries, hydropower plants. The study is an approach on developing a model that predicts the sand particle behaviors in flowing water in closed pipelines. This study involves Computational Fluid Dynamics (CFD)analysis and predicted flow behavior in different conditions in a closed pipeline for sand (solid particles) and water(liquid) using Eulerian-Eulerian multiphase flow model. The study was performed for pipe of diameter 0.3m, variable length, volume fraction (15%-35%), particles (0.02mm-0.06mm), velocity (0.5m/s-2.5m/s).The results obtained were validated with the experimental data. Results showed that maximum particle concentration increases with decrease in velocity, increase in particle size and increase in volume fractions. The maximum concentration for inlet mixture velocity of 0.5m/s and 2.5m/s velocity at outlet was found to be 0.626 and 0.515 respectively, and at midplane was found to be 0.629 and 0.498 respectively.The maximum particle concentration for 15%, 25%, and 35% of initial mixture volume fraction was 0.586, 0.612 and 0.628 respectively at outlet and 0.536, 0.587and 0.629 at midplane respectively.Maximum particle concentration for particle size of 0.02mm,0.04mm and 0.06mm are 0.307, 0.612 and 0.629 respectively at outlet and 0.349, 0.629, 0.629 respectively at midplane. Maximum particle concentration for 90° sharp bend, curved bend of mean fillet radius 180mm and curved bend of mean fillet radius 210mm at bottom are 0.576, 0.476, and 0.466 respectively. Change in length of pipe didn’t have any effect on concentration at certain point of pipe.