矩形明渠三维紊流的数值模拟

在明渠三维流动中，紊流产生的二次流起关键作用，它对主流流场分布，壁面应力及污染物的扩散有很大影响，有时还影响床面的稳定，Ｋ－ε紊流模型及类似的双方程模型不能计算这种二次流动。本文将非线性Ｋ－ε紊流模型用于明渠三维紊流的计算，模型用张量形式推出，比代数应力模型更易推广到复杂边界流动，应用这一模型及另两种代数应力模型对矩形明渠流动进行计算，所得结果，尤其是表述紊流特征的量，与实测资料进行了详细比较，并

Three dimensional numerical modelling of rectangular open channel flows

In a open channel flow, secondary flow driven by the turbulence play quite important role in the presence of the primary velocity profile, distributions of Reynolds stress and boundary shear stress. They also affects the sedimentation and dispersion phenomena. A recently developed non-linear k-epsilon turbulence model is applied to represent the three-dimensional turbulent flows in the open channel. The model has the advantage of satisfying the tensorial invariance, hence would be more easily extended to geometrically more complicated flows (compound channel flows for example). Two examples of rectangular channel flows are simulated with this model and two other existing algebraic stress models. Numerical results are compared with the experimental data, and the emphasis is given to the turbulence quantity.