Research on the Vortex Structure in Rotating Cavity Flow by means of Simultaneous

旋转空腔流涡结构的同步研究

基本信息

批准号：
09650182
负责人：
YAMASHITA Shintaro
金额：
$ 2.18万
依托单位：
Gifu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650182/
关键词：
Cavity Flow Three-Dimensional Flow Separated Shear Layer Vortex Structure Spatio-Temporal Measurement PIV Ultrasonic Velocity Profile Monitor 遠心力不安定

项目摘要

This research aims to clarify the vortex structure of the flow in a cavity formed peripherally on a cylinder rotating in a uniform axial stream. The aspect ratio, i.e., the ratio of the width of the cavity to the depth. was varied from 1 to 4. Experiments were carried out in a water tunnel, and measurements were made by using a PIV (Particle Imaging Velocimetry) and a UVP (Ultrasonic Velocity Profile Monitor). A progress of this research and main results obtained are as followings.1. The cylinder model was made, whose nose part was of streamline shape based on the axisymmetric potential flow. The cylinder was supported as a cantilever on its rear end and by fine wires on its front part.2. The soft ware for PIV measurements to analyze the images on the basis of cross-correlation method was developed, and it was refined as to measure accurately the velocity in the cavity which varied over wide range in its magnitude. Further the development of the soft ware for the simultaneous measureme … More nt with the PIV and UVP was undertaken, and the consultation was made for the tracer particles seeded in the water for this measurement. As a result we fixed to use simultaneously the fluorescent dye for the PIV and the hydrogen bubbles generated by the electrolysis of the water for the DVP.3. Following the above preliminary research, the experiment was made for the flow field in the cavity of its aspect ratio 1 and 4. First, the flow visualization with no rotation of the cylinder revealed that the cavity flow presented the vortex structure composed of a main vortex of the scale comparable to the cavity depth and of some secondary vortices as in two-dimensional cavity flow, and also that the shear layer separated at the upstream edge of the cavity oscillated and the position of reattachment point varied quasi-periodically.4. The vector map of the mean velocity and the contour map of the mean vorticity were obtained from the PIV measurement. They exhibited the magnitude and the configuration of the main vortex and the secondary vortices quantitatively. The spatio-temporal behavior of the separated shear layer was examined from the DVP measurement. The phenomenon of the spatio-temporal swaying of the shear layer was revealed, and the mean frequency of the oscillation and the space-time correlation of the fluctuating velocity in the shear layer were obtained.5. We proceed with more detailed measurements and data analyses, and will investigate the roll-up phenomenon of the shear layer, the clipping of the layer on the downstream edge of the cavity, the fluctuating vorticity distribution, and so on, in order to clarify the three-dimensional vortex structure in the axi-symmetric cavity. Less

该研究的目的是在均匀轴向流的圆柱体上形成的腔体中的涡流结构。在水隧道中，使用PIV（速度）概况监视器进行测量，并获得了以下结果。在轴上的电势流和前部部分。同时进行了测量……进行了PIV和UVP的更多信息，并咨询了在水中播种的图形，以进行测量。 .3。在亚洲研究之后，实验在其纵横比的空腔中进行了流动。二维腔流中的二维涡流在振荡的上游边缘分离，重新仪点的位置从piv测量中获得了平均涡流的轮廓图的矢量图4。 d从DVP测量中检查了主涡流的配置和次级涡流定量。测量和数据分析，并将调查剪切层的汇总现象，腔的下游边缘，波动涡度分布等，以阐明Axi中的三个三个三个三个三个三个三个三维三维涡流结构 - 对称腔。