This study has been conducted to numerically investigate and visualize the way that the entrained sand follows inside a storage tank at various flow velocities. The specific objectives of the work are to:1- Generate a CFD model for sand settlement in a cylinderical storage tank.2- Analyze the effect of flow and sand characteristics on sand deposition inside the storage tank.3- Recommend the optimum flow conditions at which minimum sand deposition takes place. A model geometry for a vertical cylindrical tank with 30 m diameter and 15 m height was created and meshed. The Discrete phase model (DPM) in Fluent has been used to perform the simulation. Sand Retention Testing data for a Malaysian oil field has been used during the solution phase to simulate sand deposition inside the tank, and then, to investigate the effect of flow characteristics on sand deposition. Sand sizes in the range of 0.01-10000 µm and inlet velocities of 1 m/s and 10 m/s have been considered during the simulation, and sand particles are tracked for each flow velocity. The high inlet velocity (10 m/s) shows high turbulence of the flow, and hence, rapid reverse flow takes place near to the inlet. This reverse flow causes the sand particles to stay afloat in the tank and eventually mass of grouped particles form near the inlet. The low inlet velocity (1 m/s), in contrast, results in higher amount of sands that can reach the tank outlet. The low turbulence behavior at lower velocity decreases the tendency of the entrained sand to float on top of the tank. The sand particles, instead, spread at the bottom of the tank with the ability of the upper layer of sand particles to flow gradually. Eventually, more sand particles can be discharged at the outlet. The simulation results presented in this paper can provide a better understanding on the way that entrained sand particles can deposit in or discharge from a liquid storage tank and it can demonstrate how flow characteristics can affect sand deposition. This can assist in setting supervisory strategies for controlling these flow characteristics to avoid or minimize sand deposition.
