水电站沉沙池水沙运动规律模拟

Simulation of Water and Sediment Movement in Sand Basin of Hydropower Station

采用Fluent数值计算模拟沉沙池的水流泥沙运动规律,并通过物理模型试验论证Fluent数值计算模拟水沙运动规律可行性,结果表明:纵向平均流速沿程呈现脉动较大衰减,前面流速波动较大,后面流速波动较小,纵向平均流速沿纵向分布越均匀,流场分布也越均匀,有利于泥沙在沉沙池内的沉降,沉沙池的沉降效果较好。受沉沙池边壁影响,水流的横向流速呈正态分布,主流偏向沉沙池内侧,流速呈现左右侧流速小,中间较大,内外侧流速差值较小,水流得到充分扩散,横向流速和横向流场均匀分布,因此纵向沉沙池沉沙效率增加,纵向泥沙含量减小。数学计算值与物理试验值相差较小,物理模型试验验证了由Fluent数值计算模拟沉沙池的水流泥沙运动规律是可行的。

The Fluent is used to simulate the movement law of water and sediment in sand basin of a hydropower station,and the feasibility of simulating the movement law of water and sediment is proved by the experiment of physical model.The longitudinal average velocity shows a large attenuation of pulsation along the flow path with bigger front velocity fluctuation and smaller back velocity fluctuation.The longitudinal average velocity distribution along the longitudinal direction is more even,the flow field distribution is more even,which is conducive to sediment settlement in sand basin,so the settlement effect is better.Influenced by the side wall of sand bank,the transverse velocity of flow presents a normal distribution pattern,the main flow is inclined to the inside of sand bank with smaller flow velocity on the left and right sides and larger flow velocity in the middle,so the difference of velocity on the outside and inside is smaller,the flow is fully diffused,the transverse velocity and the transverse flow field are uniformly distributed,that will increase the sediment settlement efficiency in vertical direction and decrease the sediment content in vertical direction.The difference between the numerical simulation value and the physical test value is smaller,so the physical model test proves that it is feasible to simulate the flow and sediment movement of sand basin by Fluent numerical calculation.