Visualization of Vortical Flow Around the Free End Surface of a Finite Circular Cylinder Mounted on a Flat Plate

Title & Authors
Visualization of Vortical Flow Around the Free End Surface of a Finite Circular Cylinder Mounted on a Flat Plate
No, Seong-Cheol; Park, Seung-O;

Abstract
A flow visualization study using the oil film method and the smoke-laser light sheet arrangement is carried out to investigate the three-dimensional flow pattern around the free end surface region of a finite circular cylinder (aspect ratios of 1.25 and 4.25) mounted on a flat plate. The experiment is performed for the cases of two Reynolds numbers: 5.92$\small{{\times}}$10$\small{^3}$and 1.48$\small{{\times}}$10(sup)5. Various kinds of singular points on the free-end surface are disclosed from the oil surface flow visualization. The smoke-laser light sheet visualization, to aid in understanding the oil streak-line patterns, clearly demonstrates that a pair of tornado-like vortices marched along the downstream together with a pair of side tip vortices. A topological sketch to characterize the surface flow and the four vortices emanating from the top surface is included.
Keywords
Finite Circular Cylinder;Oil Flow Visualization;Laser Light Sheet Visualization;Singular Point;Tornado-Like Vortex;Flow Topology;
Language
Korean
Cited by
1.
대기경계층 내에 놓인 자유단 원주의 형상비가 후류유동에 미치는 영향에 관한 연구,박철우;이상준;

대한기계학회논문집B, 2001. vol.25. 12, pp.1821-1830
2.
대기경계층 내에 놓인 실린더의 자유단 형상변화가 후류유동에 미치는 영향에 관한 연구,박철우;이상준;

대한기계학회논문집B, 2003. vol.27. 1, pp.105-116
References
1.
Farivar, D., 1981, 'Turbulent Uniform Flow Around Cylinders of Finite Length,' AIAA Journal, Vol. 19, pp. 275-281

2.
Ayoub, A. and Karamcheti, K., 1982, 'An Experiment on the Flow Past a Finite Circular Cylinder at High Subcritical and Supercritical Reynolds Numbers,' Journal of Fluid Mechanics, Vol. 118, pp. 1-26

3.
Fox, T. A., Apelt, C. J. and West, G. S., 1993, 'The Aerodynamic Disturbance Caused by the Free-Ends of a Circular Cylinder Immersed in a Uniform Flow,' Journal of Wind Engineering and Industrial Aerodynamics, Vol. 49, pp. 389-400

4.
Baban, F. and So, R. M. C., 1991, 'Aspect Ratio Effect on Flow-Induced Forces on Circular Cylinders in a Cross-Flow,' Experiments in Fluids, Vol. 10, pp. 313-321

5.
Etzold, F. and Fiedler, H., 1976, 'The Near-Wake Structure of a Cantilevered Cylinder in a Cross-Flow,' Z. Flugwiss, Vol. 24, pp. 77-82

6.
Kawamura, T., Hiwada, M., Hibino, T., Mabuchi, I. and Kumada, M., 1984, 'Flow Around a Finite Circular on a Flat Plate,' Bulletin JSME, Vol. 27, pp. 2142-2151

7.
Winkelmann, A. E. and Barlow, J. B., 1980, 'Flowfield Model for a Rectangular Platform Wing Beyond Stall,' AIAA Journal, Vol. 18, pp. 1006-1008

8.
Roh, S. C. and Park, S. H., 1998, 'Flow Around the Top Surface of a Finite Circular Cylinder Mounted on a Flat Plate,' Proceedings of 4th JSME-KSME Conference, pp. 333-336

9.
Narasimha, R. and Prasad, S. N., 1994, 'Leading Edge Shape for Flat Plate Boundary Layer Studies,' Experiments in Fluids, Vol. 17, pp. 358-360

10.
Tobak, M. and Peake, D. J., 1979, 'Topology of Two-Dimensional and Three-Dimensional Separated Flows,' AIAA paper 79-1480

11.
Chapman, G. T. and Yates, L. A., 1991, 'Topology of Flow Separation on Three-Dimensional Bodies,' Applied Mechanics, Rev. 44, pp. 329-345

12.
Hornung, H. and Perry, A. E., 1982, 'Stream Surface Bifucation, Vortex Skeletons and Separation,' DFVRL IB 222-82 A 25

13.
Delery, J. M., 1992, 'Physics of Vortical Flows,' Journal of Aircraft, Vol. 29, pp. 856-876

14.
Zdravkovich, M. M., Brand, V. P., Mathew, G. and Weston, A., 1989, 'Flow Past Short Circular Cylinders with Two Free Ends,' Journal of Fluid Mechanics, Vol. 203, pp. 557-575

15.
Hsieh, T. and Wang, K. C., 1996, 'Three-Dimensional Separated Flow Structure over a Cylinder with a Hemispherical Cap,' Journal of Fluid Mechanics, Vol. 324, pp. 83-108