The objective of this work is to analyze fluid flow in horizontal pipes with three phase gas-liquid-solid Newtonian fluid by our developed CFD simulation model and validate the simulation with experimental works. Air as gas, water as liquid and silica sand as solid particle is used for this work. ANSYS fluent version 16.2 is used to do the simulation. Eulerian model with Reynolds Stress Model (RSM) turbulence closure is adopted to analyze multiphase fluid flow. Length of pipe is 2.9 m and diameter is 0.0416 m, which are selected from experimental works to validate the simulation and after a good agreement with experimental data, sensitivity analysis is conducted to observe the three phase fluid flow characteristics through horizontal flow. Pressure gradient (pressure drop per unit length) is used as primary parameter to analyze. Effect of in situ concentration of solid in slurry, diameter of pipeline, roughness of wall material and viscosity of water in slurry are analyzed throughout this paper. This article provides validity of our proposed model. After that we tried to perform some parametric studies, changing variables of three phase fluid flow through horizontal pipeline with ours validated model. The main approach here is to demonstrate our CFD model in different ways to researchers and industries related to multiphase pipeline flow fields and make it acceptable to them. Also, Fluid Structure Interaction (FSI) is introduced at the end of this study to explain the goal of this project.