冰盖下典型复式断面河道水深平均流速的横向分布

开展冰盖下典型复式断面河道水深平均流速的横向分布规律研究,对于凌汛防治具有重要意义。本文在SKM法的基础上,结合双层假设理论,并将二次流项并入雷诺切应力项,建立了考虑河床摩擦、冰盖阻力、横向剪切湍流和二次流影响的准二维数学模型。与相应的物理模型实验结果对比发现,所提出的准二维数学模型能够合理预测复式断面河道各断面的水深平均流速横向分布及河道过流量。本文提出的数学模型,无需通过计算机编程联立求解复杂方程组,即可获得水深平均流速的横向分布特征,对研究具有复式断面的覆冰河道的水流特征具有一定的指导意义。

Lateral distribution of the average water depth of the typical compound cross-section channel under ice cover

The study of the horizontal distribution law of the depth averaged velocity of ice-coated rivers with typical compound sections is of great significance for flood control and management. Based on the SKM method, current study incorporated the double-layer hypothesis theory and introduced secondary flow term into the Reynolds shear stress to build a quasi-two-dimensional model. This model takes into account the effects of river bed friction, ice sheet resistance, lateral shear turbulence and secondary flow. Compared with the experimental results of the corresponding physical model, the proposed quasi-two-dimensional mathematical model can reasonably predict the horizontal distribution of the depth averaged velocity and river flow rate in each compound section. The mathematical model is able to capture characteristics of horizontal distribution of the depth averaged velocity without solving complex equations simultaneously by computer programming. This will provide significant guidance for the study of water flow characteristics of ice-coated river channels with multiple sections.