【作者】 蒋晶晶；

【导师】 杨玲霞； 叶春生；

【作者基本信息】 郑州大学 ， 水力学及河流动力学， 2010， 硕士

【摘要】 近年来,黄河下游洪水演进中出现了洪峰流量的异常增大现象。目前的研究认为,异常现象的发生可能与水流和泥沙共同作用下较易发生糙率改变有关。从数值计算的角度研究糙率变化对圣维南方程组数值解的影响,不仅有助于解释洪峰增值的异常现象,而且具有一定的理论价值。论文的研究内容包含以下几个方面：(1)给出了含糙率的一维和二维明渠非恒定流基本方程(即圣维南方程组)。(2)利用有限体积法,采用正交的交错网格系统剖分求解域。(3)结合亚松弛技术和TDMA算法,利用SIMPLE算法求解水深～速度耦合场。(4)给定初始条件、水位边界条件以及多组糙率值,在清水条件下对洪水的演进过程进行数值模拟。(5)结合数值模拟的结果,初步探讨了糙率变化以及流量叠加对异常现象的解释。更多还原

【Abstract】 In recent years, it’s always seen the unusual phenomenon of flood’s peak discharge increasing while routing at the Lower Yellow River. According to the current study, it may be related to the roughness’slight change due to the interaction between stream and sediments. It will not only help to explain the phenomenon through the analysis of the impact of roughness’s slight change on the numerical solution of Saint-Venant equations, but also has theoretical value.The thesis focuses on the following aspects,(1) 1D and 2D Saint-Venant equations of unsteady open channel flow are given.(2) The Finite Volume method and orthogonal staggered grid are used to divide the solution domain.(3) With sub-relaxation technique and TDMA algorithm, the coupled field of the water depth and velocity are iteratively solved by SIMPLE algorithm.(4) Under the condition of clear water and after initial and boundary conditions introduced, the flood routing is simulated as to different roughness values.(5) The numerical simulation results are summarized and analyzed to discuss the unusual phenomenon due to slight change of roughness or discharge integration.更多还原