3D Numerical Modeling of Flow in Sedimentation Basin

Abstract

Abstract. Normal operation sedimentation basin flushing systems require large volumes of water, typically up ten times of the deposited sediment volume for efficient flushing. A complete sediment removal, can only be realized by combination of mechanical removal with drawdown flushing. This operation reaches much longer operation time resulting in water loss and reducing power and energy production of Mini Hydro Power Plant (MHPP). The objective of this study is to improve the flushing system of sedimentation basin based on a numerical approach. Fluid motion is described with non-linear, transient, second-order differential equations. A numerical solution of these equations involves approximating the various terms with algebraic expressions. The resulting equations are then solved to yield an approximate solution to the original problem. The simulation result shows that the 3D numerical modeling of flow in sedimentation basin gives the reasonable result to predict the suspended load movement in the flow.

Modelling of Flow and Scour Around the Piers With Different Geometric Shapes

“…The flow can be modelled by using continuity equation, momentum equation, and the volume of fluid equation in Cartesian coordinate [9,10]. These equations are presented in equation 1 to 3 below.…”

“…ℎ 𝑠𝑠 = 1,35 D 0,7 ℎ 1 0,3 (10) The equation of pier scour based on experiment [19] is given as: ℎ 𝑠𝑠 = 𝐷𝐷 𝑘𝑘 𝛼𝛼 𝑘𝑘 𝐼𝐼 𝑘𝑘 𝜕𝜕 𝑘𝑘 𝜇𝜇4 𝑘𝑘 𝜎𝜎 (11) Sediment gradation coefficient (𝑘𝑘 𝜎𝜎 = 1,0) and flow intensity coefficient (𝑘𝑘 𝐼𝐼 ) use the equation as below.…”