水电站压力管道流固耦合水击计算的研究

发布时间：2018-06-08 16:14

本文选题：水击 + 压力管道　；参考：《昆明理工大学》2017年硕士论文

【摘要】：管道是水利水电枢纽中一种极其重要的输水、引水部件,连接管道的阀门或者水泵机组会经常性地启闭(停),阀门的启闭或者水泵机组的启停会造成有压管道内的流体产生水力暂态过程,当这种水力暂态过程严重时,会产生水击这种极端的非恒定流动现象。水击的发生会给管道系统的安全运行带来巨大的影响,因为其产生的巨大的压强增高或者降低会以水击波的形式在管道系统中传播。当管道的约束形式为弱约束形式时(除了地下埋管等在沿程施加了强约束的管道之外,均可以将其定义为弱约束管道),水击产生的压力升高或者降低会促使管道的振动,管道的振动又会重新引起新的水力暂态过程,所以这时管道系统内并存管道、流体两种介质的相互耦合作用,这就是所谓的管道系统中的流固耦合作用。求解水击的理论可以分为经典水击理论和流固耦合水击理论。经典水击理论早在200多年前就被有的学者提出来了,该理论考虑的条件较少且对真实情况做了许多简化,同时没有考虑管道的动力特性,由于该理论在指导实际工业生产的过程中简单易行,虽然其精确度不高,但是在过去一直被广泛采用。随着社会的进步和科学技术的发展,尤其是上世纪60年代以来发展起来的有限元法等数值求解技术在水击方面的应用,使得水击的流固耦合求解方法吸引了广大的专家和学者的注意力。在最近几十年发展起来的耦合水击求解法,其研究历程经历了由简单到复杂的过程。本文在理清了经典水击理论的数学模型及其求解方法(特征线法)的基础上,重点研究了 ADINA软件中流体模型和结构模型的计算程序所用的方程及其离散形式。最后利用ADINA软件的FSI求解模块对本文所要研究的问题做了数值模拟。整个流程的具体过程是:首先使用本文第二章所提出的经典水击理论特征线解法和第三章提出的流固耦合水击交错积分弱耦合解法对同一个模型进行了求解,并通过两种算法的求解结果做了对比,说明使用流固耦合算法来计算水击的必要性;然后基于ADINA软件对不同阀门关闭时间、不同管道长度、不同管壁厚度等情况做了流固耦合数值模拟;最后采用英国丹迪大学的压力管道的流固耦合实验数据和本文所提出的流固耦合计算做了对比,验证了本文所使用的流固壀合算法的合理性。
[Abstract]:The pipeline is an extremely important water conveyance and diversion component in the water conservancy and hydropower hub. The valve or pump unit connected to the pipeline will open and close frequently (stop, the opening and closing of the valve or the start and stop of the pump unit will result in the hydraulic transient process of the fluid in the pressurized pipeline, when the hydraulic transient process is serious, Water hammer is an extreme unsteady flow phenomenon. The occurrence of water hammer will bring great influence to the safe operation of pipeline system, because the great pressure increase or decrease will propagate in the form of water hammer wave in pipeline system. When the constraint form of a pipeline is a weak constraint form (except for a pipeline with strong constraints along the path, such as buried underground pipes, etc., it can be defined as a weakly constrained pipeline, the increase or decrease of pressure generated by water hammer will promote the vibration of the pipeline. The vibration of pipeline will cause new hydraulic transient process again, so the interaction between fluid and fluid in pipeline system is called fluid-solid coupling. The theory of solving water hammer can be divided into classical water hammer theory and fluid-solid coupling water hammer theory. The classical water hammer theory was put forward by some scholars as early as 200 years ago. The theory takes less conditions into account, simplifies the real situation and fails to take into account the dynamic characteristics of pipelines. Because the theory is simple and easy to use in the process of guiding actual industrial production, although its precision is not high, it has been widely used in the past. With the progress of society and the development of science and technology, especially the application of numerical solution technology such as finite element method developed since 1960s in water hammer, The fluid-solid coupling solution of water hammer has attracted the attention of many experts and scholars. The coupled water hammer solution developed in recent decades has experienced a process from simple to complex. On the basis of clarifying the mathematical model of classical water hammer theory and its solution (characteristic line method), the equations and discrete forms of fluid model and structure model in Adina software are studied in this paper. Finally, the FSI solution module of Adina software is used to simulate the problems to be studied in this paper. The concrete process of the whole process is as follows: firstly, the same model is solved by the characteristic line method of the classical water hammer theory proposed in the second chapter of this paper and the weak coupling solution of the fluid-solid coupling water hammer staggered integral proposed in the third chapter. The results of the two algorithms are compared to illustrate the necessity of using the fluid-solid coupling algorithm to calculate the water hammer, and then based on Adina software, the different valve closing time and the different pipe length are analyzed. Numerical simulation of fluid-solid coupling has been done with different wall thickness. Finally, the fluid-solid coupling experimental data of the pressure pipeline of the University of Dandy in England have been compared with the fluid-solid coupling calculation proposed in this paper. The rationality of the fluid-solid combination algorithm used in this paper is verified.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV732.4;TV134.1

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