基于FLUENT的便携式泥沙起动测量装置模拟效率与精度

Research on Simulating Efficiency and Accuracy of Portable Sediment Incipience Measuring Device Based on FLUENT

现场测量粘性细颗粒泥沙临界起动条件方法众多,便携式泥沙起动测量装置以其轻便快捷的优点越来越受到关注。利用成熟的商业流体计算软件FLUENT分别建立二维、三维数值模型,从模型维度、湍流模型、膨胀层网格3个方面对便携式泥沙起动测量装置的模拟效率与精度进行研究。结果表明,二维简化模型与三维模型的计算结果吻合较好,但二维模型的计算效率比三维模型高的多;RNGκ-ε、Realizable κ-ε湍流模型模拟所得底部床面产生的水流剪切力基本相同;膨胀层网格可在提高数值模型计算结果精度的同时减少模型总网格数量,提高模型计算效率。该结果可为泥沙起动装置设计和数值模拟研究提供参考。

There are many methods for in situ measuring the incipient motion of fine cohesive sediment.The portable sediment incipience measuring device is more and more concerned by researchers because of its convenience and fast advantages.In this paper,the mature commercial fluid calculation software FLUENT was used to establish two dimensional and three dimensional numerical models,respectively.The simulation efficiency and precision of the portable incipience measuring device were studied from three aspects of model dimension,turbulence model and inflation layer grid.The results show that the two dimensional simplified model agrees well with the three dimensional model,while the calculation efficiency of the two dimensional model is much higher than that of the three dimensional model.Bottom flow shear stress on the bed simulated from the RNG κ-ε and Realizable κ-ε turbulence model are almost the same.Inflation layer can reduce the number of total meshes and improve the accuracy of the calculation results while improving the calculation efficiency of the model.The research results can provide reference for sediment incipient device design and numerical simulation research.