弯曲型及顺直型河道水流三维数值模拟

Three-dimensional Flow Numerical Simulation in Straight and Meandering Channels

采用标准k-ε模型、RNG k-ε模型、可实现k-ε模型和Reynolds应力模型共4种紊流模型,对梯形断面连续弯道三维水流运动特性进行了数值模拟。从水面线、水流流速、紊动结构及分布特性等方面,比较了4种紊流模型计算结果与实测值的差别。结果表明,Reynolds应力模型由于考虑了水流紊动黏度的各向异性效应,对弯道水流运动特性的模拟精度高于其他3种k-ε模型。进一步采用Reynolds应力模型对连续弯道对应的同长度、同断面型态的顺直河槽进行计算,用实测值验证了Reynolds应力模型也能较好地适用于顺直河槽的水流运动模拟。研究成果可用于弯曲型及顺直型河道水流的三维模拟计算中。

The paper uses four turbulent stress models,including standard k-εmodel,RNG k-εmodel,Realizable k-εmodel and Reynolds stress model,to numerically simulate the three-dimensional consecutive-bend flow of trapezoidal section continuous curve.From the aspects of water surface line,water flow velocity,turbulent structure and distribution characteristic etc.,the differences between the calculated results and the measured values of the four turbulence models are compared.The results show that the Reynolds stress model has higher accuracy than the other three models because of the anisotropic effect of the turbulent viscosity of the water flow.The Reynolds stress model is further used to calculate on straight channel which has the equal length and same cross section in geometry with the consecutive-bend.It is verified by the measured values that the Reynolds stress model can be well applied to the simulation of the water flow in the straight channel.The research results can be used in the three-dimensional simulation calculation of curved and straight river flow.