为研究间距比和倒角半径对并列不等直径柱体绕流水动力特性的影响，采用大涡模拟（LES）方法，数值模拟3种间距比L/D和5种倒角半径R+并列布置不等直径柱体的三维流场。验证数值方法的准确性，分析柱体后方受力特性、瞬时流场和时均流场的变化情况。结果表明：倒角变化能改善柱体剪切层的分离发展，同时减小柱体所受的阻力和升力，随着R+的增大，3种L/D下大柱的Cd-ave和Cl-rms总体呈现出减小趋势，最大降幅分别为38.6%和92.3%。L/D变化对柱体后方流场和尾流形态有较大影响，随着L/D的增大依次观察到两柱体后方的2种尾流形态，即偏斜流态和双涡脱落流态。研究结果可为相关工程设计根据不同影响因素选取合适的倒角柱体提供参考。
To study the effects of spacing ratio and rounded corner radius on the hydrodynamic characteristic of flow around two parallel cylinders with unequal diameters, the three-dimensional flow field of the two cylinders with three spacing ratios and five rounded corner radii was numerically simulated by using the large eddy simulation (LES) method. The accuracy of this numerical method was validated, and the variation of hydrodynamic characteristics, instantaneous flow field and time-averaged flow field of the cylinders were analyzed. The roundness can improve the separation development of the shear layers, while reducing the drag and the lift forces on the cylinders. As the R+ increases, the Cd-ave and Cl-rms of the larger cylinder at all L/D show a decreasing trend and the maximum decrease is 38.6% and 92.3%, respectively. The L/D has a significant effect on the wake pattern and the flow field behind the cylinders. Two wake patterns behind the two cylinders are observed with increasing of L/D, that is skewed flow pattern and double vortex shedding flow pattern. The results can provide a reference for relevant engineering designs to select suitable rounded corner cylinders according to different influencing factors.
2023,45(21): 26-31 收稿日期：2022-12-1
DOI：10.3404/j.issn.1672-7649.2023.21.005
分类号：TV143
基金项目：国家自然科学基金资助项目(51739010)
作者简介：于定勇（1964-），男，博士，教授，研究方向为海洋动力与结构物和岸滩作用
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