Experiment and Nemerical Prediction for Onset of od Three Diemnsional Separation

在资助期间，核实或设计下列项目：1. 提出了一种简单的可视化技术，为拖曳槽中沿模型的极限流线提供示踪记录。采用电解法，将酚酞溶液涂在人体表面。举例说明了在轴对称抛物面上和沿垂直于平板的圆柱上的可视化结果。旋转抛物面的计算结果与Bippes的计算结果吻合得很好，闭合分离线起始的临界角高达62°左右。氢气泡法也被用于可视化流场中的涡动。对于抛物面的情况，可以观察到侧向涡的交替脱落。在风洞中测量了抛物面上的静压，并在主要分离线后证实了二维分离时的azunytgak应力分布平台。在柱板结合处附近的流动可以观察到节点、鞍和焦点。焦点的位置随圆柱体后面的双涡的长度而周期性地移动。针对三维Navier - Stokes方程和边界层解的有限差分计算结果，开发了三维流动的计算机图形化说明技术。

During the term of the Grant-in -aid the following items are verified or devised. 1. A simple Visualization technique is proposed which provides a record of tracer for the limitting streamlines along a model in a towing tank.Electrolysis method is applied with painting the phenolphtalein solution on a body surface. The visualization results over axisymmetric paraboloid and along a circular cylinder normal to flat plate are shown as examples.2. The results for paraboloid of revolution show a good agreement with those by Bippes as for the critical angles for the onset of closed separation line as high as 62 deg or so.3. Hydrogen bubble methods is also applied to visualize vorticis in the flowfields.For the case fo paraboloid the alternative shedding of lateral vortices canbe observed.4. Static pressure over the paraboloid was measured in a wind tunnel and a plateau of azunytgak oressyre distribution as in 2-D seqaration was confirmed behind primary separatin lines.5. As for the flow near the cylinder-plate juncture the nodes,saddles,and foci can be observed.The locations of foci move cyclically with the length of twin vortices behind the cylinder.6. Illustrating techniques of three dimensional flows in computer graphics are developed for the results of finite difference computation for tridimensional Navier Stokes equations as well as boundary layer solutions.