二维扰动对下游圆盘压力分布的影响

Effects of two-dimensional interference on pressure distribution of a circular disk

通过测量阻力和表面压力,研究了干扰圆柱尾迹产生的二维扰动对下游圆盘气动特性的影响,得到圆盘迎风面压力分布的变化规律,并结合以往流场结构的研究,对其机理进行了分析.结果表明在圆盘与干扰圆柱间距比L/D较小时,圆盘迎风面低压区宽度随间距增大迅速增加;当L/D>0.7时,对于同一直径的干扰圆柱,圆盘迎风面低压区宽度基本保持不变;对于不同直径的干扰圆柱,在圆盘前产生低压区的宽度随圆柱直径的增加而变大.此外,利用这种干扰方法,可以降低圆盘阻力,实验得到圆盘阻力可减少约9%,相应的圆柱/圆盘系统的阻力可减小4%.

The effects of two-dimensional disturbance, induced by a circular cylinder placed upstream, on the aerodynamic characteristics of a circular disk have been investigated in wind tunnel. The pressure distribution on the windward surface of the disk was studied with different cylinder diameters and spacing distances. The mechanism of the passive flow control method was discussed combined with previous flow visualization experiments. When the non-dimensional spacing （L/D） between the cylinder and the disk is below 0.7, the low-pressure area on the windward surface of the disk expands rapidly with the spacing increase. While the spacing ratio L/D is greater than 0.7, the low-pressure area keeps in a constant value with the increase of the spacing （ the cylinder has the same diameter） , and the low-pressure area increases with the cylinder diameter increase. In addition, this disturbance technique can reduce the drag of the disk, and the maximum drag reduction is up to 9% of that of the isolate disk. The corresponding drag of the cylinder-disk system can be reduced by about 4%.