串列多方柱气动特性的试验研究

Tests for aerodynamic characteristics of tandem multi-square columns

为研究串列多方柱的气动特性,采用刚性模型测压风洞试验的方法研究了雷诺数为3.2×104时,间距比在1.2~8范围内,串列双方柱和串列三方柱在不同间距比下的风压系数、升阻力系数以及斯托罗哈数。结果表明:串列双方柱的临界间距比在3~3.5之间,串列三方柱存在两个临界间距比,分别在2.5~3和3.5~4。通过串列双方柱和三方柱的对比可以看到:在双方柱下游增加一个方柱会显著影响其气动特性,平均阻力系数的绝对值、脉动升力系数和斯托罗哈数均在间距比L/D≤3.5时减小,但在间距比L/D≥4时这种减小效果减弱。风压分布与原双方柱相似,但数值有所不同,在间距比为3.5时差异最为明显。位于双方柱下游的方柱其气动力及风压系数在间距比为2.5~3时突然增大,在间距比为3.5~4时则相反。

In order to study aerodynamic characteristics of tandem multi-square columns,wind pressure coefficient,lift and drag coefficients,and Strouhal number of tandem 2 square columns and tandem 3 square columns with different spacing ratios were studied by using the rigid model pressure measurement wind tunnel test method when Reynolds number was 3.2×104 and the spacing ratio was in the range of 1.2-8.The results showed that the critical spacing ratio of tandem 2 square columns is 3-3.5,and tandem 3 square columns has two critical spacing ratios of 2.5-3 and 3.5-4.Through comparing tandem 2 square columns and tandem 3 square column,it was shown that adding a square column downstream of tandem 2 square columns can significantly affect the aerodynamic characteristics of the original tandem 2 square columns,the absolute values of its average drag coefficient,pulsating lift coefficient and Strouhal number all decrease when the spacing ratio L/D≤3.5,but this reduction effect weakens when the spacing ratio L/D≥4,the distribution of wind pressure is similar to that of the original tandem 2 square columns,but their values are different,their difference is the most obvious when the spacing ratio is 3.5;the aerodynamic force and wind pressure coefficient of the added square column increase suddenly when the spacing ratio is 2.5-3,and vice versa when the spacing ratio is 3.5-4.