Flow characteristics study of fly ash slurry in hydraulic pipelines using computational fluid dynamics

Abstract

Transportation of fly ash slurry via pipelines has been recognized as a potential economical and dependable mode of solid transportation. It also bids various other advantages over the conventional means of transportation. For improved understanding of the flow characteristics of these pipelines, investigators throughout the world have been analyzing the flow experimentally numerically and theoretically. Slurry pipeline systems are regularly used crosswise the world for the transportation of fly ash from the power plant to the ash ponds. These pipeline are very much energy exhaustive and also leads to disproportionate and inordinate wear of pipelines and wastage of water. Objective of the present work is to conduct a methodical and logical study of fly ash slurry transportation in a pipeline at higher concentrations by the use of computational fluid dynamics and study the flow characteristics and pressure drops. An effort has been made in this study to develop comprehensive slurry flow model using CFD and utilize the model to predict pressure drop and validating the results with the calculated results. A broad computational fluid dynamics (CFD) model was established in the current study to gain understanding into the solid liquid slurry flow in pipelines. The approach adopted in here is studying and solving the problem by mathematical modeling method. In this work, the solid suspension in a fully developed pipe flow was simulated and analyzed A 20m pipe with a diameter of 0.5m is modeled, through which flow is conducted where modelling and meshing is done using ANSYS Fluent. High viscosity fly ash slurry with five different concentrations, 50%, 60%, 65%, 68% and 70% by weight of fly ash is passed and for each concentration five different velocities like 3, 3.5, 4, 4.5 and 5 m/s are used and pressure drops are calculated. Other characteristics studied are volume fraction, eddy viscosity and turbulence kinetic energy.