Practical computational method of open channel unsteady flows including sub ＆ super critical flows

明渠非定常流（包括亚临界流和超临界流）的实用计算方法

基本信息

批准号：
12660215
负责人：
SHIMADA Masashi
金额：
$ 1.54万
依托单位：
THE UNIVERSITY OF TOKYO
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

The explicit scheme, proposed by Moll (1998) using the Saint Venant equations in the conservation form, is advanced toward its establishment of a practical numerical method of computing coexisting subcritical and supercritical flows through analyzing how to incorporate calculations at boundaries. The scheme suppresses spurious oscillation due to numerical errors by incorporating the flux limiter in the easier calculation algorithm. Especially, the calculations at a connection between two channels with each different slope is theoretically analyzed. A set of the finite-dirrerence equations and boundary condition gives two bifurcated relations : one is valid for flows except for critical flows and the other valid for critical flows. With these the explicit scheme becomes hopeful method of analyzing unsteady flows where a control section, a hydraulic jump, and bore are given to examine the analysis on boundary calculations. In addition, connections between two channels of different cross sections such as circular or rectangular ones, where the flows change from ordinary to another ordinary flows, are dealt with to solve the finite-difference equations, the boundary conditions, and the momentum equation proper to the connection boundary. The some computational examples are given by calculations of unsteady flows including supercritical and subcrtical flows situations and/or a bore (translatory jump) in simple and rather complicated channel systems.

Moll (1998) 提出的显式方案使用守恒形式的圣维南方程，通过分析如何在边界处合并计算，朝着建立计算共存的亚临界和超临界流动的实用数值方法迈进。该方案通过将通量限制器纳入更简单的计算算法中，抑制了由于数值误差而产生的寄生振荡。特别是对具有不同斜率的两个通道之间的连接处的计算进行了理论分析。一组有限相关方程和边界条件给出了两个分叉关系：一个对于除临界流之外的流动有效，另一个对于临界流有效。有了这些，显式方案成为分析非定常流的有希望的方法，其中给出了控制部分、水跃和孔来检查边界计算的分析。此外，还处理不同横截面（例如圆形或矩形通道）的两个通道之间的连接，其中流动从普通流动变为另一种普通流动，以求解有限差分方程、边界条件和动量方程连接边界。一些计算示例是通过对非定常流的计算给出的，包括简单和相当复杂的通道系统中的超临界和亚临界流情况和/或孔（平移跳跃）。