基于图形界面的管网非恒定流显-隐格式联合求解

Method of explicit-implicit scheme for unsteady flows in pipe network based on graphical interface

目前水电站过渡过程数值分析主要是采用面向过程设计基于特征线法的程序,本文从水击的基本方程出发,结合数值计算中显格式与隐格式的优点,提出一种将显格式与隐格式联合用于管网非恒定流计算的思路,建立相应的基于图形操作界面的自动编码与自动分层方法,实现引水发电系统图形化建模,并以追赶法为基础,提出管网隐式差分格式计算的分层并行解法,解决管网中非棱柱体管道及短管在显格式计算中处理困难的问题,实现计算效率与计算精度的综合最优。文中还结合某工程实例,数值仿真对比了等价与真实尺寸尾水管在机组甩负荷过程中压力值的差别。

Numerical simulation at present for study of transient flows in the penstock system of a hydropower station is majorly based on the method of characteristics and structured programming. Based on the fundamental equation of water hammer, a method combining explicit scheme and implicit scheme for unsteady flow calculation of pine network is described in this paper. A related method of auto-coding and auto-grading based on graphic operation interface and a hierarchical parallel computation algorithm originated from chasing method, have been developed to solve the problem of short-pipeline and non-prismatic pipes in explicit scheme, which is a comprehensive optimum on computational efficiency and accuracy. The difference of pressure in the draft tube between equivalent pipe and actual pipe is verified in an engineering case study of loading rejection condition.