盲肠回流泥沙运动机理初析

本文以实验观察得到的物理模式为基础,依据Plandtl边界层理论、湍流的半经验和统计理论,及有关旋转流体的特性,建立了描述盲肠口门处水流泥沙运动的系统数学模型。并运用分解协调技术和Blasius相似解思想,求得模型的分析解和近似分析解。文中论述了主副流动量交换、泥沙扩散、平面回流结构和立体环流结构等理论问题。在VAX/VMS系统上进行了数值模拟,结果表明,理论和实测资料符合得较好。

On the Mechanism of Water-Sediment Motion in Caecum-Form Rivers

Based on experimental observation, the complete water and sediment motion system of a caecum-form river is decomposed into several subsystems such as those with back flow and those with turbulent jet flow. The Prandtl boundary layer theory and statistical mechanics of turbulence are then used to work out mathematical models, which are simplified versions of Navier-Stokes equation and Fick molecular diffusion equation, to describe the water and sediment motion in the zones with turbulent jet flow, Analytical solutions as well as a formula for calculating the deposit rate of the sediment in back flow have been obtained. Laboratory test data and field experimental data show that the analytical results are correct. The correctness of the semi-empirical formula given by Prof. Xie Jianheng is also verified by the deposit rate formula. Theoretical coefficients are found to be within the range of experimental ones measured. By taking the back flow in the caecum-form river as the superposition of two circulation flows, the 3-dimensional Navier-Stokes equation is solved it-eratively. The first degree approximation obtained, a 2-dimensional flow field and the water-surface configuration of the back flow are in agreement with laboratory data.