【作者】 韩宇；

【导师】 吕宏兴；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2010， 硕士

【摘要】 灌溉渠道在执行配水计划的输水过程中需要不断调节流量,调节后渠道中的水流将会产生非恒定流的过渡过程,这一水流现象可以通过数学方法用圣·维南方程组描述。不同数值方法在求解不同复杂输水系统水力过渡问题时,会表现出各自的特点及不同程度的适用性。圣·维南方程这一双曲型偏微分方程组数值求解的常用离散方法有两种:Preissmann法及特征线法。本文应用不同算法进行比较,选择既能保证计算精度又可以提高计算速度的算法。Preissmann四点隐式差分法有多种解法,本文采用了追赶法和Rootcanal软件中的牛顿-拉斐逊法进行模型计算,同时也利用特征线法求解控制方程,通过三种方法计算求解同一典型渠段,对三种方法的精度及适用性进行比较。由于特征线法编程思路清晰,精度也能达到工程要求,用此模型计算甘肃引大总干渠实际渠道的非恒定流过渡过程,并选取该灌区进行原型观测的部分渠段数据,进行了数值模拟结果的模型验证。为了保证灌溉渠道的运行安全以及调配水量,模拟线性渠段的非恒定流过渡为其重要环节,本文考虑到渠系运行的不同方式以及节制闸存在的不同调控,按照灌区常用的上游常水深运行、下游常水深运行,应用特征线法的矩形网格计算格式,模拟模型渠段节制闸在对流量不同调控时引起的非恒定流过渡过程,应用此模型可以预报出总干渠道上各节制闸调闸时间的提前量,并且给出线性调节过程。自动化控制渠道的核心在于闸门的自动化监控系统的设计与实施。通过对渠道设计规划原则的研究,剖析了闸站的自动化监控系统体系结构,提出了计算模型在自动化控制中的重要作用,并且强调了渠系自动化在今后灌区发展中的重要地位。建立简便的渠系非恒定流计算模型程序能全面地反映系统的动态变化过程,并对其运行作出预测。同时对非恒定流模拟软件Rootcanal作了应用性介绍,对软件的局限性作以补充。非恒定流计算模块添加内边界条件节制闸后,可得到较明确的闸门调节过程,通过对多种方案的模拟可得到系统最佳运行状态,这对灌区配水管理和工程管理有较大的参考价值。更多还原

【Abstract】 To operate the water distribution plan, it is necessary to regulate the discharge in canal.This phenomenon can be described by an math method of Saint-Venant. Using the different numerical method to resolve the hydraulic transients problems in many complex water distribution system can reflect their feature and applicability. For Saint-Venant nonlinearity hyperbolic partial differential equations of the numerical algorithms have two kinds: Preissmann and Characteristic method. According to resolve a typical canal by different methods, we choose a method which can guarantee the precision and improve the speed of calculate. Preissmann implicit 4-node difference method have various solution, in this article we choose the two sweep method and the Newton-Raphson method in Rootcanal to calculate it, then we use Characteristic method to calculate it too. In the same typical canal, we compare these methods. Depending on the Characteristic method programming ideas clearly, accuracy and achieve the engineering requirements ,we use it into Yin Da engineering in Gan Su province for simulating the process of unsteady flow, and we can validation model by the data we get from the field.To research unsteady flow transition process in single irrigation canals for the purpose of ensuring the safe operation of irrigation canals and rational allocation of water, we consider the different operating mode, as well as the different gate regulation mode etc. under the condition of constant upstream water depth operation and constant downstream water depth operation, the canals unsteady flow numerical simulation of rectangular grid characteristic method was used, simulating the canal under the different gate control and forecast earlier time to control the sluice at all levels, fully reflected more precise adjustment process.The key of automation control canal depend on the design and implement of automation gate monitor system. Based on the principle of planning and design research, analyzes the gate of automatic monitoring station system structure, puts forward the important position of calculation model in the automatic control system, and emphasizes the development of automation in irrigation area is an important position.The canal flow control model is simple, convenient, the program can comprehensively reflect the dynamic system and its operating forecast, because of the new software Rootcanal, we implant their defect. The mode of unsteady flow calculation add the inner condition can get a clear gate adjustment process. Based on the simulation we can get best operation system of irrigation, the water management and project management is a great reference value.更多还原