不同湍流模型对海水淡化用提升泵模拟精度的影响

Influence of Various Turbulent Flow Models on the Precision of Simulating a Seawater Desalination-purpose Lift Pump

针对双蜗壳型式的海水淡化用提升泵,运用Fluent软件,分别采用标准k-ε、RNG k-ε和Realizable k-ε湍流计算模型进行数值模拟。分析3种不同湍流模型中蜗壳与叶片的流场情况,在此基础上进行了性能预测,并与试验结果进行比较。研究表明:采用RNG k-ε湍流模型计算时,中叶轮和蜗壳内部流线比较流畅,性能预测结果与试验结果吻合较好;采用k-ε和Realizable k-ε湍流模型计算时,叶轮和蜗壳流线紊乱、产生漩涡,性能预测结果与试验结果相差比较大。RNG k-ε湍流计算模型更适合海水淡化用提升泵和类似结构离心泵的性能预测,为海水淡化用提升泵及类似双蜗壳结构离心泵的性能预估和数值模拟提供一定参考。

By using software Fluent,a numerical simulation was performed of a dual volute type seawater desalination-purpose lift pump by employing the standard k-ε,RNG k-ε and Realizable k-ε turbulent flow calculation models respectively.Furthermore,the flow fields inside the volute and blades were analyzed by using the three turbulent flow models.On this basis,a performance prediction was conducted and compared with the test results.The research results show that when the RNG k-ε turbulent flow model is used for calculation,the streamlines inside the impeller and volute are comparatively smooth and the performance prediction result is in relatively good agreement with the test one.When the k-ε and Realizable k-ε turbulent flow model are used for calculation,the streamlines inside the impeller and volute are disordered with vortexes being produced and the performance prediction result has a relatively big difference from the test one.The foregoing indicates that the RNG k-ε turbulent flow calculation model is more suitable for the performance prediction of seawater desalination-purpose lift pumps and centrifugal pumps with the same structure.The research results can provide a certain reference for performance prediction and numerical simulation of seawater desalination-purpose lift pumps and centrifugal pumps with the same dual volute structure.