三维溃坝波对下游结构物致灾过程数值模拟

Numerical Simulation of Flooding Process on Downstream Structure by Three-dimensional Dam-break Wave

暴雨等自然灾害形成的溃坝对下游结构物安全存在潜在威胁,溃坝对结构物的破坏非线性强且机理复杂,基于自主研发三维并行模型,探究水灾害流固耦合动态响应过程。通过并行算法实现加速计算,利用流体体积法捕捉自由面,采用浸入边界法处理流固耦合。定量预报溃坝洪水过境流速和冲击载荷,通过实际案例、公开数据对比论证数学模型处理水灾害流固耦合问题的可靠性。溃坝波携带大量动能和势能,全流场信息可描述在短时间内多次变化的溃坝致灾流态,水流推进与跌落的过程易形成冲刷作用,传导到结构物的冲击载荷易破坏工程结构,致灾机理研究为防灾减灾提供科学依据。

Dam break caused by natural disasters,such as heavy rainfall,poses a potential threat to the safety of downstream structures.It brings damages to the structures with a strong nonlinearity and complex mechanism.Based on an in-house three�dimensional parallel model,the dynamic response process of the fluid-structure interaction caused by water disasters is investigated.The accelerated computing is achieved by the parallel algorithm,the free surface is captured by the volume of fluid method,and the fluid-structure interaction is dealt with by the immersed boundary method.While a quantitative forecast of the flow velocity and impact load during the dam-break flood is carried out,the reliability of the mathematical models in dealing with the fluid-structure interaction of water disasters is demonstrated by real-life cases and published data comparison.Dam break wave carries a large amount of kinetic and potential energies.The information of the whole flow field describes the disaster-causing flow patterns that change many times in a short period.Water advancing and falling make it easy to form scouring,and the impact load transmitted to the structure is apt to damage the engineering structure.This study of disaster-causing mechanism provides a scientific basis for disaster prevention and mitigation.