广西浔江长洲枢纽回水长度变化规律研究

水库回水长度解析解在理论上和简单数模理想算例中均得到了验证，但目前尚无实际工程的检验。在介绍分析水库回水长度解析理论的基础上，应用二维水流数学模型，模拟研究了广西浔江长洲枢纽回水长度变化规律，实例验证了回水长度解析理论的正确性。同时，应用解析理论分析了数学模型计算结果的合理性，并分析讨论了两种回水计算方法的关系，以及现实回水计算一般难以观测到回水极值现象原因。计算分析结果表明：回水长度计算的两种方法均具有一定的合理性，有关回水长度变化规律的传统认识是回水长度解析理论的一种特殊情况。

Backwater Length Variation Law in Changzhou Junction of Guangxi Xunjiang River

The analytical theory of backwater length in reservoir area has already been verified by theoretic analysis and simple ideal numerical example.Furthermore,the analytical theory of backwater length in reservoir area needs to be confirmed in practical engineering.In this paper,based on the introduction of theoretic analysis on backwater length in reservoir area,the backwater length variation law in Changzhou Junction of Guangxi Xunjiang River was studied using a 2-D numerical model,in which a practical example is presented to demonstrate the validity of analytical theory of backwater length.Meanwhile,the reasonability of the results from numerical model was analyzed by the analytical theory of backwater length.And the relationships between the solving methods of analytical theory and numerical model were discussed.The reason for the phenomenon that the extreme value of backwater length is difficult to be obtained in practice was also analyzed.The results from the calculation indicated that the two methods are both reasonable,and the traditional knowledge about the rule of backwater length variation is one of the special cases of the analytical theory of backwater length in reservoir area.