槽道中串联双圆柱流致振动响应特性研究

Numerical Simulation on Flow-induced Vibration Response of Two Tandem Arranged Cylinders in Channel

该文采用了格子Boltzmann方法对槽道中直径相同的串联双圆柱的流致振动特性进行了详尽的数值研究。结果表明,上下游圆柱横向振动时,不同间距比(S/d=1.1~8.0)、圆柱阻塞率(β=0.20~0.45)、来流雷诺数(Re=100~700)和质量比(M=0.05~4.00)对串联双圆柱的运动模态影响显著。不同参数下,运动圆柱的运动模式存在较大差异:当圆柱间距小(S/d=1.7)且Re=400时,圆柱间的剪切层和涡旋脱落,导致圆柱振动时的不同周期振幅不同,进行振动幅度不同的多周期振动;圆柱间距小且Re=700时,来流和剪切层对振动的影响大于涡旋对振动的影响,圆柱进行振幅相同的大幅对称振动;当圆柱间距大且圆柱的阻塞率较小时,两个圆柱均在通道同一侧大幅振动;当圆柱间距大且阻塞率较大时,上下游圆柱均大幅对称振动,β>0.25时圆柱位移差达最大值。增大圆柱质量比,圆柱的运动模态从多周期振动先后转变为对称大幅振动和单侧大幅振动。

In this article,a comprehensive numerical investigation of the flow-induced vibration characteristics of two tandem cylinders with the same diameters is present using the lattice Boltzmann method.The results indicate that the y-axis vibration of both upstream and downstream cylinders are significantly influenced by several key parameters,including the spacing ratio(S/d-1.1-8.0),the blockage ratio(β-0.20-0.45),the Reynolds number(Re=100-700)and the mass ratio(M-0.05-4.00).Various modes of motion of the vibrating cylinders are observed under different parameter combinations.In cases when the cylinder spacing is relatively small(S/d-1.7)and Re=400,the vortices between the cylinders and the shear layer can lead to multi-period vibrations with varying amplitudes.In contrast,at Re-70o,the effects of incoming flow and the shear layer on vibration mode over the vortex street,the cylinders periodically oscillate around the channel center line with large amplitudes.When the spacing ratio is large and the blockage ratio is small,both cylinders oscillate on the same side of the channel.Conversely,when the blockage ratio is large,both upstream and downstream cylinders display large symmetric vibrations,with the cylinder amplitude reaching its maximum value atβ>0.25.Moreover,a large mass ratio of the cylinders leads to a transition in the motion mode from multi-period vibrations to symmetric large vibrations.The cylinders eventually oscillate on one side of the channel.