Schlieren visualization of vortices and internal waves generated by vertical stroke oscillations of a disk
Schlieren visualization of vortices and internal waves generated by vertical stroke oscillations of a disk
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圆盘垂直冲程振荡产生的涡流和内波的纹影可视化
DOI：
10.1007/bf03181904
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发表时间：
2008
影响因子：
1.7
通讯作者：
E. Stepanova
中科院分区：
文献类型：
--
作者：
Y. Chashechkin;E. Stepanova
如图所示为连续分层盐水中，直径d = 6.4 cm的水平薄盘在浮力周期b T s下进行双振幅H峰垂直振荡所引起的涡流侧视图。采用的纹影方法sp(1)有“狭缝线对焦”和“水平光栅对焦”(2)。图像的着色是由盐水中光线的自然分散引起的(2)。视场直径23厘米。一次半冲程运动只在下半空间产生内波和中心涡。圆盘上方的细曲线是从圆盘表面分离出来的上升气泡的痕迹。薄的锥形界面直接在流体内部形成，并在圆盘下方的蘑菇状漩涡中逐渐重新转化。全行程产生占据整个空间的内波和自动累积的射流，即圆盘下方的蘑菇状涡(3)。自动累积射流在流体内部形成并向圆盘移动。它的尖端作为一个额外的瞬态内波的瞬时源。磁盘边缘诱导涡的图像与经过移动条带的下游涡相似(4)。
Side view of vortex flow induced by thin horizontal disk of diameter d = 6.4 cm performing vertical oscillations with double-amplitude peak H in a continuously stratified brine with the buoyancy period b T s is shown. Used schlieren methodsP(1) are “slit-thread in focus” and “horizontal grating in focus”(2). Colouring of the image is caused by natural dispersion of light in the brine(2). Diameter of view field is 23 cm. One half-stroke motion produces internal waves and central vortex only in the lower hemi-space. Thin curved lines above the disk are traces past ascending gas bubbles separated from the disk surface. Thin conical interface is formed directly inside the fluid and gradually retransformed in the mushroom-like vortex below the disk. Full stroke produces internal waves occupying the whole space and autocumulative jet that is mushroom-like vortex below the disk(3). Autocumulative jet is formed inside the fluid and moves towards the disk. It’s tip acts as an additional instantaneous source of transient internal waves. Images of disk edge induced vortices are similar to downstream vortices past moving strip(4).