基于重叠网格的桥墩防撞浮箱流场特性数值研究  

Numerical Study on Flow Field Characteristics of Anti-collision Pontoon for Bridge Pier Based on Overset Grid

作　　者：冀楠 杨光 舒麟棹 钱志鹏 万德成[2] JI Nan;YANG Guang;SHU Linzhao;QIAN Zhipeng;WAN Decheng(School of Shipping and Naval Architecture,Chongqing Jiaotong University,Chongqing 400074,China;Computational Marine Hydrodynamics Laboratory(CMHL),Shanghai Jiaotong University,Shanghai 200240,China)

机构地区：[1]重庆交通大学航运与船舶工程学院,重庆400074 [2]上海交通大学船海计算水动力学研究中心(CMHL),上海200240

出　　处：《重庆交通大学学报（自然科学版）》2023年第3期26-35,77,共11页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：国家重点研发计划项目(2018YFB1600400);2021年度重庆市研究生科研创新项目(2021S0044)。

摘　　要：为了揭示桥墩加装防撞浮箱后的水动力性能及流场特性,基于重叠网格方法,以典型的圆形自浮式浮箱-桥墩系统为例,采用雷诺应力(RSM)湍流模型,利用VOF方法捕捉自由液面,同时考虑浮箱升沉位移,建立了三维数值计算模型。通过与实验数据对比,验证了数值仿真方法的合理性和结果精确度;以重叠网格技术实现浮箱的升沉垂荡运动,研究了水流流速和水深变化对防撞浮箱的升沉垂荡、动力响应和流场特性的影响。研究结果表明:水流流速主要影响防撞浮箱的升沉位移值,而水深主要影响防撞浮箱的垂荡历程;防撞浮箱在3个方向上的力系数基本都是随水深的增加而下降,但较低流速时,力系数随水深的增加下降趋势较为平缓,纵向力系数随水深的增加先略微上升后再下降;防撞浮箱的垂荡与垂向力有关,较低流速下浮箱垂向力的变化周期随水深的增加而增大,较高流速下,防撞浮箱产生强烈的垂荡,周期变化规律完全消失。In order to reveal the hydrodynamic performance and flow field characteristics of pier equipped with anti-collision pontoon,taking the typical circular self-floating pontoon pier system as an example,the Reynolds stress(RSM)turbulence model was adopted on the basis of the overset grid method.Using the VOF method to capture the free surface and taking into account the buoyancy tank heave displacement,a three-dimensional numerical calculation model was established.Firstly,the rationality of the numerical simulation method and the accuracy of the results were verified by comparing with the experimental data.Then the sinkage and heave motion of the floating tank was realized by using the overset grid technology.The effects of the changes of flow velocity and water depth on the sinkage and heave,dynamic response and flow field characteristics of the anti-collision floating pontoon were studied.The research results show that:the flow velocity mainly affects the heave displacement of the anti-collision pontoon,while the water depth mainly affects the heave process of the anti-collision pontoon.The force coefficients of the anti-collision pontoon in three directions basically decrease with the increase of water depth,but at a low flow velocity,the downward trend of the force coefficients with the increase of water depth is relatively gentle,and the longitudinal force coefficients first increase slightly and then decrease with the increase of water depth.The heave of the anti-collision pontoon is related to the vertical force.The variation period of the vertical force of the anti-collision pontoon increases with the increase of water depth at a lower flow velocity.At a higher flow velocity,the anti-collision pontoon produces strong heave and the periodic variation law disappears completely.

关 键 词：桥梁工程 船舶工程 防撞浮箱 桥墩绕流 重叠网格 马蹄涡 垂荡 

分 类 号：U443.26[建筑科学—桥梁与隧道工程]