【作者】 金英；

【导师】 程耿东；

【作者基本信息】 大连理工大学 ， 流体力学， 2005， 硕士

【摘要】 为了考虑水体的粘性对升船机船-水-厢耦合系统的影响,论文首先推导了应用Rayleigh粘性系数和非线性波动理论的粘性流体控制方程,经摄动法分解后运用迦辽金有限法进行有限元离散,得到水体的一、二阶速度势方程组。将流体的控制方程和刚体运动方程耦合,建立了完整的考虑水体粘性的、船-水-厢系统耦合有限元方程组。 采用与三峡升船机船厢子系统1:50比例的实验模型,我们观察了不同频率,不同粘度下水体自由面的波动情况,测量了波幅随时间的自由衰减的变化值,得到系统的粘性衰减率。分析所得到的实验数据并和数值计算结果比较,我们发现表面粘性系数和系统粘性衰减率呈线性关系。 利用从实验中得到表面粘性系数,我们在时域上求解了完整的船-水-厢耦合系统的有限元方程组,并将结果与理想流体的船-水-厢时程分析比较,发现粘性的存在使得水面的晃动迅速衰减,而二阶水波的非线性影响更明显。 最后,本文通过大量数值计算和实验数据分析,给出了一些较有意义的结果,以供三峡升船机工程设计参考。更多还原

【Abstract】 To consider the effect of the viscosity on the ship-water-chamber coupling system of the ship left, the present thesis derives the governing equations of the viscous fluid based on the theory of Rayleigh viscous coefficient (also called surface viscous coefficient in this thesis) and the non-linear water-wave equation. Using the perturbation theory the water-wave equation was divided into first order and second order velocity potential equations and the corresponding finite element matrix equations have been derived by means of Galerkin method. Furthermore, the general stiffness matrix was formed and the finite element matrix equations about the general displacement of the rigid structure were derived. The equations of the fluid and the rigid structure were combined into a new equation by using the variable parameters of water pressure.Second, a scale model of the ratio 1:50 to the real Three Gorge ship lift was created. This model was used to observe the vibration of the free surface under the different frequencies and viscosities, measure the amplitude damping along with time. This data is used to calculate the viscous damping rate. In the experiment, the linear relation of surface viscous coefficient and the system viscous damping rate is proven, consequently, the method about how to gain the value of surface viscous coefficient was found.On the basis of the experiment, the analysis of the whole fluid-solid coupled equation in the time domain is completed. Compared with the ship-water-chamber of the irrotational, incompressible, homogeneous fluid, the effect of the viscosity is not only on the rapid damping of wave disturbance, but also on smoothing the second order non-linear water wave.Last, many numerical calculations of the above work were performed and some interesting results were given.更多还原