多级丁坝影响下弯道水流运动三维数值模拟研究

Three-dimensional Numerical Simulation of Water Movement in Curved Channels Influenced by Multi-stage Spur Dikes

多级丁坝在航道整治工程中应用广泛,为了研究其水流结构,在U形弯道内布设多级丁坝进行系列水槽试验,采用粒子图像测速(PIV)仪和超声波水位计测量了多级丁坝附近的流速及水位,同时利用商用软件Fluent,基于有限体积法,采用RNG k-ε湍流模型,对丁坝附近水流的流态进行三维数值模拟,并将水槽试验结果与数值模拟结果进行了对比分析。结果表明,两者吻合较好。模拟结果表明:相同过流面积下,丁坝级数增加,丁坝下游回流范围增大,坝头处高流速区流速值减小;在水流近底处和中截面处,紊动能k最大值随着丁坝级数的增加逐渐减小,在自由水面处则先增大后减小。

The multi-stage spur dike is widely used in waterway regulation.In order to study the water flow structure,a series of flume experiments were conducted by placing multi-stage spur dike in U-shaped flume,and the flow velocity and water level near the multi-stage spur dike were measured by PIV and ultrasonic level meter.The flow pattern of water near it was also simulated numerically in three dimensions by using commercial software Fluent based on the finite volume method and the RNG k-εturbulence model.The experimental results of the flume were compared and analyzed with the numerical simulation results.The results show that the two are in good agreement.The simulation results show that with the same flowing area,when the spur dike stage increases,the downstream circumfluence range increases,and the velocity at the high velocity zone at the head of the spur dikes decreases.Near the bottom and middle cross section of the flow,the maximum turbulence energy k decreases gradually with the increase of the stages of spur dike,but firstly increases and then decreases at the free water surface.