三峡电站流量变率对两坝间通航水流影响的三维计算分析

摘要

The waterway between Three Gorges Dam (TGD) and Gezhouba Dam is tortuous and varied.The unsteady flow caused by the discharge and daily regulation of TGD powerplant complicates the navigation conditions between the two dams.We established a 3-D mathematical model to simulate the unsteady flow caused by the operation of power units.By analyzing the calculation results,we obtained the variation regularity of water surface water gradient and surface water velocity in typical segment between the two dams in the presence of different operation time s and discharges.Results show that:with the shortening of the operation time of power units,the increment of surface water gradient in the most hazardous segment intensified,and the maximum surface velocity increased linearly; while with the increase of discharge,the surface water gradient and maximum surface velocity increased linearly.%三峡至葛洲坝两坝间航道曲折多变、水流条件复杂,三峡电站在泄洪和日调节时产生的非恒定流,使得两坝间的航行条件更为复杂.通过建立两坝间通航水流三维数学模型,针对电站机组开启过程下泄流量变率产生的非恒定流对两坝间河段通航水流条件的影响,开展了计算分析研究.计算分析了三峡电站机组不同开启时间和不同开启流量情况对典型河段水面比降、表面流速产生的影响及其变化规律.研究结果表明:机组开启时间变化情况下,通航最困难河段水面比降增幅随机组开启时间缩短而加大,但最大表面流速线性增大；机组开启流量变化情况下,水面比降和最大表面流速随下泄流量线性增大.