混流式水泵水轮机驼峰区数值模拟及分析

Numerical simulation and analysis of the hump district of Francis pump-turbine

本文基于三维定常Navier-Stokes方程和重整化群κ-ε湍流模型,采用贴体坐标、非结构化网格和有限体积法,对水泵水轮机模型在某一导叶开度下的泵工况进行全流道内部流场模拟。采用CFD技术模拟分析水泵水轮机泵工况的特性,经与试验结果比较,研究所得数值模拟结果能较为准确地预测水泵水轮机在泵某特定工况下的特性。本文介绍了利用数值模拟的结果对特性曲线驼峰区处的流速分布、涡分布进行的分析研究,并对水泵水轮机泵工况特性曲线驼峰区形成原因进行了初步的分析。

A finite volume method with unstructured mesh and body-fitted coordination was used in this study to solve the Navier-Stokes equations and a RNG κ-ε model for simulation of the flow through the whole passage of a pump-turbine under different operation modes at a fixed guide vane opening.Comparison with the experimental results shows that the simulations achieve a high accuracy in predicting the characteristics of pump-turbine under the modes studied.This paper focuses on an analysis of the simulations,particularly on the velocity distribution and vortex distribution in the hump district and its hydrodynamic mechanism.