基于SPH方法的开孔沉箱比尺效应研究  

SPH study on scale effect of perforated caisson

作　　者：金瑞佳 韩丽影 贺铭 耿宝磊[1] 张华庆[1] JIN Ruijia;HAN Liying;HE Ming;GENG Baolei;ZHANG Huaqing(Tianjin Research Institute of Water Transport Engineering, MOT, Tianjin 300456, China;College of Engineering, Ocean University of China, Qingdao 266100, China;Ningbo China Communication Water Transportation Design and Research Co., Ltd., Ningbo 315040, China;Tianjin Key Laboratory of Harbour and Ocean Engineering, Tianjin University, Tianjin 300350, China)

机构地区：[1]交通运输部天津水运工程科学研究所,天津300456 [2]中国海洋大学工程学院,山东青岛266100 [3]宁波中交水运设计研究有限公司,浙江宁波315040 [4]天津大学天津市港口与海洋工程重点实验室,天津300350

出　　处：《海洋工程》2022年第3期61-68,共8页The Ocean Engineering

基　　金：国家自然科学基金项目(51709201,51809133);中国博士后科学基金项目(2019M652479);中央级科研院基本科研业务资助项目(TKS20200406)。

摘　　要：由于在前壁上设置了尺寸较小的孔,开孔沉箱受流体黏性力作用显著,依照弗劳德数相似准则设计模型存在比尺效应。为揭示比尺效应,建立了模拟波浪与开孔沉箱相互作用的光滑粒子流体动力学(SPH)模型。其中流体运动由连续性方程和Navier-Stokes方程控制,固壁边界由改进的动力边界粒子施加。模型收敛性通过分析不同粒子分辨率下的波浪反射系数得到,模型精度通过比较计算与理论波浪反射系数证明。使用经过验证的SPH模型,计算并比较了不同几何比尺和开孔率下开孔沉箱附近的涡量场、箱体外侧的波面时程曲线和波浪反射系数。结果表明,随着模型几何比尺的减小,开孔沉箱受到偏大的流体黏性力,致使更多波能在湍流运动中耗散,进而减小了波浪反射系数并降低了箱体外侧的波面高度。A perforated caisson is subjected to significant viscous force by fluid due to the relatively small slots on its front wall.Thus,the model design based on the Froude similarity encounters the scale effect.To reveal the scale effect,a smoothed particle hydrodynamics(SPH)model for simulating wave interactions with perforated caissons is built.In the SPH model,the fluid motion is governed by the continuity equation and Navier-Stokes equations,and the solid boundary is implemented using modified dynamic boundary particles.Wave reflection coefficients under different particle resolutions are analyzed to obtain the numerical convergence,and the numerical and theoretical wave reflection coefficients are compared to demonstrate the numerical accuracy.The validated SPH model is then used to calculate and compare the vorticity fields near the perforated caisson,the wave elevation curves in front of the caisson and the wave reflection coefficients under different length scales and porosities.The results show that with the decrease of the model length scale,more wave energy is dissipated in turbulent motion because the perforated caisson is subjected to greater viscous force by fluid.Correspondingly,both the wave reflection coefficient and the wave height in front of the caisson decrease.

关 键 词：开孔沉箱 比尺效应 SPH方法 涡量场 波浪反射系数 

分 类 号：TV139.2[水利工程—水力学及河流动力学]