基于VOF模型的虹吸管流动数值模拟

摘要

基于 FLUENT软件,通过合理设置上、下游水池进出口边界条件满足管道水头在虹吸过程中保持不变的要求,在流量未知、虹吸过程中管道上下游水位保持恒定条件下模拟虹吸管道过流能力及流场特性。应用标准k-ε模型和 VOF方法对安装高度为1 m,不同管道上下游水位条件下虹吸流动过程进行数值模拟。计算出虹吸管过流能力、速度场、压降随水头的变化规律。将计算结果与物理试验结果相比可知,随上、下游水位差增大,管道过流能力和压降值增大,速度场和压降特性与有压管流一般规律相符。流量计算值与实测值最大相对误差为2.00%,最小相对误差为0.72%,压降计算值与实测值最大相对误差为4.86%,最小相对误差为0.36%。表明所选的数学模型、边界条件的设置方法合理可行,该方法可用来模拟流量未知、管道上下游水位已知时非驼峰式虹吸管的流动特征。%To simulate the siphon channel flow capacity and flow field characteristics under the condition of different upstream and downstream water level,k-εand VOF method in a fluid numerical software FLUENT was used to analyze two-phase flow patterns.The numerical simulations of siphon flow process were conducted under the condition of different upstream and downstream water level.The siphon flow ca-pacity,velocity field,pressure drop were calculated with change law of water head.It was found when calcu-lated result and physical test result were compared with the increase of the upstream and sownstream pipe flow capacity and pressure drop increased the characteristics of velocity field were almost the same as that of pressure pipe flow.The greatest relative error between flow calculation value and measured value was 2.00%,the smallest relative error was 0.72%.The relative error between pressure drop calculated value and measured value was 4.86%,the smallest relative error was 0.36%,which showed that mathematival mod-el,boundary condition setting method was feasible.The method can be used to simulate the flow character-istics of non-camel siphon when the flow is unknown and the pipeline is known.