摘要
本文用边界元方法研究了绕平壁上一薄平板的Stokes流动。数值模拟了薄平板与平壁成不同倾角φ时的流场。我们发现:当φ=π/2时,平板左右两侧形成大小相等的两个涡旋,其涡心到角点的距离为平板高的0.54倍;当φ=5π/12时,平板两侧仍然形成两个涡旋,不过平板右侧5π/12角内的涡旋明显大于平板左侧的涡旋,其涡心距角点的距离右侧是平板高的0.68倍,左侧是0.29倍;当φ=π/3时,平板左侧的涡旋已经消失,右侧π/3角内仍然形成一个涡旋;而当φ=π/12时,平极左右两侧均无涡旋。我们还数值分析了流场中形成涡旋时的涡心位置与平板倾角φ之间的关系,并给出薄平板上的面力与压力的分布曲线,数值模拟的流场与Tancda的实验结果比较完全一致。
In this paper, the various phases of Stokes flows passing over a fence on a flat-iplate inclining different angles with the flat plate are studied by the use of the BF.M (Boundary Fle-ment Method). The velocity fields of numerical simulation show that when the flow passes over the fence which is mounted vertically on the flat plate (0 = p/ 2), a large Vortex is formed within the corner, and the distance between the vortex center and the corner point is about 0.54 times the height of the fence. When the flow passes over the (<p =) 5 n / 12 fence, it may be seen that the size of a vortex within the7n/ 12 corner is much smaller than other vortex within the corner of 5n/ 12, and the distance between the vortex center and corner point is 0.29 times height of the fence in the 7n/ 12 corner, and 0.68 times the fence height in the 5n/ 12 corner. When the flow passes over the n/3 fence, a vortex is formed within the corner of n/ 3 but within other corners there is not a vortex. When the How passes over the n/ 12 fence, there is not a vortex within the two corners of the fence. In particular, we also calculated the distributive curves of the surface force and the pressure on the fence, these being difficult in the experiment but being very important. By comparison, the numerical simulation of velocity fields are in good agreement with Taneda's experimental results.
出处
《上海力学》
CSCD
1994年第1期67-73,共7页
Chinese Quarterly Mechanics
关键词
板
边界元法
涡旋流动
Boundary Element Method, Stokes flow, Vortex.
