【作者】 李华；

【导师】 伍超；

【作者基本信息】 四川大学 ， 水力学及河流动力学， 2003， 硕士

【摘要】 立轴旋涡现象在电站引水管、溢洪道、导流隧洞、大型水泵、船闸输水廊道等进水口前时有发生。它的存在，将给水工建筑物和水电设备带来严重的危害，造成巨大的经济损失。但由于立轴旋涡涉及学科门类众多，机理复杂，自由面与水工建筑物等边界条件难于模拟，研究难度大。 本文从实际流体运动微分方程出发，结合立轴旋涡运动规律和流场特征，采用对称恒定性假设，简化N—S方程，研究了立轴旋涡的水流流态、速度与压力的分布规律，分析了若干理论解，如平面螺旋流解、轴向流解等。同时还研究了柯氏力对立轴旋涡产生的影响。 运用数理统计的方法分析了模型试验与工程原型立轴旋涡现象的观测数据，立轴旋涡的比尺效应研究具有新意，讨论了模拟立轴旋涡运动的各种准则。设计了试验室小型模型，进行了试验研究，分析了临界淹没水深的计算方法，总结了立轴旋涡的发展过程，研究了立轴旋涡对孔口流量的影响。 在立轴旋涡的研究中，本文采用了水气两相流的VOF方法与K—ε模型，首次进行了三维流场的数值模拟，得出了旋涡流场的全场特性，与过去相比，更为真实全面地模拟了立轴旋涡的运动规律。分析了立轴旋涡自由面的形成过程，总结了立轴旋涡运动形态，对旋涡吸气现象、流场压力、速度分布等进行了研究。结合两种不同的流量与环量对立轴旋涡的运动形态进行了对比。同时分析了进水口的淹没水深、出流流量、环量与边界条件对立轴旋涡产生和运动的影响。四川大学工学硕士学位论文 结合实际工程中电站进水口进行了模型试验和数值模拟。通过模型试验研究，分析了立轴旋涡的运动形态，研究了流量、水深与立轴旋涡的关系。数值模拟采用了实际地形资料，设置了喇叭口和通气孔，对进水口前旋涡流场进行了模拟，与模型试验结果符合良好。更多还原

【Abstract】 The vertical vortex is a normal hydraulic phenomenon before intakes of hydraulic structure such as diversion pipeline of hydraulic power station, spillway, diversion tunnel, high-power water pump, canal for water conveyance. The existence of vertical vortex will decrease the discharge ability, influence the efficiency of hydraulic turbine generator unit, increase the fluctuation of water and absorb the floating substances. Those can endanger seriously hydraulic structure or hydraulic equipment and impose huge economic loss. However, due to its complexity, breakthrough in vertical vortex has not been made by far. The research result cannot satisfy the need of engineering design.In this paper, according to practical liquid differential equation ,allowing for moving rule and characteristic of moving field of vertical vortex , simplifying N-S equation, I have studied the discipline of condition, velocity and pressure of vertical vortex and analyzed some theory solutions such as plain vortex solution and solution in axial direction.The observed data of vertical vortex model test and prototype are analyzed. The study of scale effect of vertical-axial vortex is a little novel. Many rules of model movement of vertical-axial have been discussed. A little model in laboratory was designed for experiment. This article analyzed calculating means of critical submergence depth, summed up developing process of vertical vortex and studied effect on discharge of orifice by vertical vortex.In the study of vertical vortex, VOF method of two phases of water and air and K-ε model have been applied. Three-dimensional moving field is numerically simulated first in this paper and characteristic of the whole vortex moving field has been acquired. The moving discipline of vertical vortex has been simulated more factually by contrast with previous study. The developing process of free face of vertical-axial vortex has been analyzed. Moving shape of vertical vortex has been summed up. Inspirations of vortex, pressure of moving field and distributing of velocity have been studied. With two different flux and circulation moving shape of vertical vortex has been compared. At the same time the effect of submergence, outflow and boundary condition of intake and moving of vertical vortex have been analyzed.Model test and numerical simulation have combined with practical power station. Through model test the moving shape of vertical-axial vortex has been analyzed and the relationship of flux, submergence with exit of vertical-axial vortex. In numerical simulation, practical landform data and set up horn-shape intake and air vent pipe are adopted. The moving shape of vortex has been simulated and the result of model test accords with simulation result well.更多还原