Abstract To investigate the effect of suction control on the aerodynamic characteristics of an elliptical cylinder immersed in uniform flow, wind tunnel tests of four elliptical cylinder models E1~E4 with different locations of suction holes were carried out under different suction flux coefficient CQ. The Re number based on the equivalent diameter of each model and the oncoming wind speed is about 6.90 ​× ​104. The results show that CQ, the radial angles of suction holes and the placement of main axis of the elliptical model are the main influence factors for the aerodynamic characteristics, which are mainly reflected in terms of the pressure coefficient distributions and aerodynamic force coefficients. There is a threshold value of CQ for the models under suction control, and a significant change of the aerodynamic characteristics occurs when CQ is within it, while the change turns to be unobvious with the further increase of CQ. And the threshold values of CQ are determined to be 0.01, 0.02 and 0.01 for the models E1, E2 and E4 respectively. Among the cases that the major axis of elliptical cylinder is parallel to the oncoming wind direction, the most effective aerodynamic control is acquired by the model E2 whose suction holes are arranged at the leeward side corresponding to the radial angles of 130° and 230°, and the maximum reduction of CD is about 83.7% at CQ ​= ​0.05 when compared to the case without suction control. The aerodynamic characteristics are also significantly improved by suction control for the case that the major axis of elliptical cylinder is perpendicular to the oncoming wind direction, and the maximum reductions of CD, CσD and CσL are about 62.2%, 75.1% and 87.4% respectively.

中文翻译：

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吸力控制对椭圆筒气动特性的影响

摘要 为研究吸力控制对椭圆筒浸没在均匀流中的气动特性的影响，在不同吸力通量系数CQ下，对4个椭圆筒模型E1~E4进行了不同吸力孔位置的风洞试验。基于各型号等效直径和迎面风速的Re数约为6.90×104。结果表明，CQ、吸入孔的径向角度和椭圆模型主轴的位置是影响气动特性的主要因素，主要体现在压力系数分布和气动力系数方面。吸力控制下的模型有一个 CQ 阈值，当CQ在其中时，气动特性发生显着变化，而随着CQ的进一步增加，变化变得不明显。对于模型 E1、E2 和 E4，CQ 的阈值分别确定为 0.01、0.02 和 0.01。在椭圆筒长轴与迎面风向平行的情况下，最有效的气动控制是E2型，其吸气孔布置在下风侧，对应径向角为130°和230°，与没有吸力控制的情况相比，在 CQ = 0.05 时 CD 的最大降低约为 83.7%。椭圆筒长轴垂直于迎面风向的情况下，通过吸力控制也显着改善了空气动力学特性，