摘要
实验通过设定一系列的KC数、β数,调整双圆柱之间间隙,对在静水中并列振荡的双圆柱系统的阻力系数、升力系数和附加质量系数进行了研究。实验发现,与单个圆柱的振荡相比,双圆柱系统在间隙较小的排布下并列振荡时的阻力系数和升力系数增大;同时在KC数较小时,附加质量系数提前趋于稳定,升力系数提前出现二阶频率。为了进一步从流场角度解释上述现象,研究进行了基于浸入边界法的Lily-Pad进行数值模拟。通过调整参数,数值模拟了与实验相同条件下的双圆柱和单圆柱流场。通过对数值模拟中单圆柱和双圆柱系统的流场分析发现,在双圆柱系统的振荡中,两圆柱之间携带大量能量的涡流是阻力系数增大的原因。
In this research,the hydrodynamics of dual oscillating cylinders under side-by-side arrangement has been studied for its prevailing presence as well as its important academic value in ocean engineering.At the aim of observing the hydrodynamic performance of a dual oscillating cylinders system reflected by drag force coefficient,lift force coefficient and added mass coefficient,key non-dimensional parameters,including KC(Keulegan-Carpenter)number,βnumber and gap between two isolated cylinders,are designated and chosen rationally.It is found that when the dual cylinders system is oscillating at a small gap,large increases occur in drag and lift force coefficients,meanwhile,the tendency that added mass coefficient becomes stable at smaller KCnumber and the earlier appearance of lift force coefficient’s second-order frequency under low KCnumber are observed,which are distinct compared to single cylinder oscillation.Numerical simulation based on Boundary Data Immersed Method has also been performed,which verified such phenomena.Then,after analyzing the flow patterns of dual cylinders and single cylinder extracted from the numerical simulation,a strong jet flow is observed in the gap between two cylinders.Through the computation of energy outflow,this jet flow which carries a large amount of energy is the reason for the increase of drag force coefficient under side-by-side configuration when the gap ratio is small.
作者
及春宁
谭沛森
仵柏衡
JI Chun-Ning;TAN Pei-Sen;WU Bai-Heng(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China;College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266100,China;Department of Marine Technology,Norwegian University of Science and Technology,Trondheim 7491,Norway)
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2019年第6期104-112,共9页
Periodical of Ocean University of China
基金
国家自然科学基金项目(41476052)资助~~
关键词
双圆柱
正弦振荡
水动力学系数
数值模拟
BDIM算法
dual cylinders
sinusoidal oscillation
hydrodynamic coefficient
numerical simulation
BDIM
