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

这项研究旨在阐明在均匀轴向流旋转的圆柱体上形成的空腔中流动的涡流结构。纵横比，即，腔宽度与深度的比率。从1到4。在水隧道中进行了实验，并使用PIV（粒子成像速度计）和UVP（超声速度档案显示器）进行测量。这项研究的进展和获得的主要结果如下1。制作了圆柱模型，其鼻子部分基于轴心电势流的流线形状。圆柱体在其后端和前部的细线上被支撑为悬臂。2。开发了基于互相关方法分析图像的PIV测量软件，并进行了完善，以准确测量腔中的速度，该速度在其大小的范围内变化了。此外，对简单测量值进行了软件的开发……进行了PIV和UVP的更多NT，并对在水中播种的示踪剂颗粒进行了咨询以进行测量。结果，我们固定将PIV的荧光染料和由DVP的水的电解产生的氢气气泡3。遵循上述初步研究，对其纵横比1和4进行的流动场进行了实验。首先，流动可视化无需旋转圆柱体的旋转，表明腔流程表明，腔流程呈现了涡流结构，该涡流结构由量表的主要涡流组成，与腔深度相比，与某些次级涡流中的偏端相比，并在二层循环中，也是在两层循环中，也是在两层循环中的涡流，也是如此，并在两层循环中，并在正常的范围内均匀地旋转。振荡和保留点的位置变化了准时4。平均速度的矢量图和平均涡度的轮廓图是从PIV测量中获得的。他们揭示了主涡流的大小和配置和二级涡流的定量。从DVP测量中检查了分离的剪切层的空间行为。揭示了剪切层空间摇摆的现象，并获得了振荡的含义频率和剪切层波动速度的时空相关性。5。我们进行了更详细的测量和数据分析，并将研究剪切层的卷起现象，腔体下游边缘上层的剪辑，波动的涡度分布等等，以阐明Axi-Metresmetric腔中的三维涡流结构。较少的