基于FLUENT三维数值模拟的溃坝洪水流动特性分析

Flow Characteristics Analysis of Dam-break Flood Based on FLUENT Three-dimensional Numerical Simulation

为了研究溃坝水流在演进过程中的水位变化规律及负波的存在对水流演进过程产生的影响,利用FLUENT软件建立溃坝洪水三维数值模型,对溃坝时水面流动状态进行数值模拟分析。该模型耦合VOF法和k-ε紊流模型求解雷诺平均N-S方程,采用有限体积法将模型离散为六面体结构性网格,并用PISO算法进行数值求解。考虑下游有水的全溃坝、下游无水设障碍物的全溃坝、下游无水的局部溃坝3种工况,分别模拟计算溃坝水流的流动状态,首先通过与前人的实验数据进行对比分析,验证了该数值模型的正确性,然后分析溃坝水流在3种工况下水流水位变化趋势和分布状况,进一步研究了溃坝水流的流动特性和演进过程。

In order to simulate the flow state of water surface during dam-break to study the law of water level change and the influence of negative wave on the evolution process of dam-break flow, 3-D numerical model has been developed by FLUENT. The model solves the Reynolds-Average Navier-Stokes equations by using the Volume-Of-Fluid(VOF) method and k-ε model. The finite volume method is used to separate the model into hexasome structural mesh, and PISO algorithm is used to solve problems numerically. The flow state of dam-break flow is simulated and calculated respectively under three conditions: dam-break with water downstream, dam-break without water downstream but obstacles and partial dam-break without water downstream. The simulation results are compared with the experimental data of predecessors to verify the correctness of the numerical model. Then the trend and distribution of water level of dam-break flow is analyzed under three conditions to further study the flow characteristics and evolution process of dam-break flow.