串列三圆柱绕流的时均压力分布与气动力

Time Averaged Pressure Distribution and Aerodynamic Force of Flow Around Three Circular Cylinders in Tandem Arrangement

运用刚性模型测压风洞试验方法对单圆柱、不同间距串列双圆柱和串列三圆柱绕流的时均压力分布与气动力进行了研究。首先,进行单圆柱模型和不同间距串列双圆柱模型的绕流试验,试验的雷诺数为3.4×104;其次,通过与单圆柱进行对比,讨论了气动干扰对串列三圆柱时均压力分布与时均阻力的影响规律;最后,通过与串列双圆柱进行对比,讨论了圆柱的数量对干扰规律的影响。试验结果发现,串列三圆柱的绕流存在两个完全不同的流态,其切换的临界间距(L/D)cr在3.5~4.0之间,两个流态下的时均压力分布与时均阻力存在明显的差异。本研究可对实际工程中串列圆柱结构的风荷载取值提供参考。

In order to provide a reference for wind load value of circular cylinder structures in tandem arrangement,time averaged pressure distribution and aerodynamic force of flow around single circular cylinder,two and three circular cylinders in tandem arrangement under different spacing are investigated through pressure-measured rigid model wind tunnel tests.The spacing ratio L/Dfor two and three circular cylinders in tandem arrangement ranges from 1.2 to 12.0,where Dis the diameter of single circular cylinder and Lis the distance between the centers of two circular cylinders.The Reynolds number is 3.4×104.Aerodynamic interference effects on time averaged pressure distribution and drag force of three circular cylinders are discussed by comparing to those of single circular cylinder.The variation of interference effect with number of cylinders was studied by comparing with those of two circular cylinders.The research results show that there are two different flow fields for three circular cylinders in tandem arrangement.The critical spacing ratio,(L/D)cris between 3.5 and 4.0.There exists significant differences between time averaged pressure distribution and drag force under two flow fields.