隔板对阵风来流下圆柱绕流特性的影响

Effect of a splitter plate on the flow around a circular cylinder under gust conditions

本文通过对阵风来流下圆柱-隔板模型气动力、变形与流场的同步测量,分析了隔板对阵风来流下圆柱-隔板模型绕流特性的影响.隔板长度L与圆柱直径D之比为L/D=1,基于来流速度U_(∞)和圆柱直径D的雷诺数Re_(D)=2×10^(4).结果表明,隔板同样能降低阵风来流情况下圆柱绕流的阻力,减阻量为13%.同时,阵风来流下模型气动力脉动大幅增加,而柔性隔板变形与流场涡脱落的耦合使气动力脉动进一步增大.此外,阵风来流主导旋涡形成前流场中的速度脉动.由于隔板的存在导致剪切层伸长,旋涡形成长度增加,阵风来流的影响范围扩大.

The effect of a splitter plate on the flow around a circular cylinder under gust conditions was analyzed through synchronous measurements of aerodynamics,deformation,and flow field.The length of the plates is equal to the diameter D of the cylinder,and the Reynolds number Re is 2×10^(4).Results showed that the drag of a circular cylinder with an attached splitter plate is reduced by 13%under gust conditions.However,the aerodynamic force fluctuation increases significantly because of the gusts and further increases because of the coupling between the deformation of the flexible splitter plate and the vortex shedding in the flow field.In addition,the gusts increase the velocity fluctuation before vortex formation.With the attached splitter plate,the shear layers of the cylinder are elongated,which expands the domain of the gusts’effect.