Abstract
A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out for a Reynolds number based on the pattern wavelength (λ) of 3080. The results depict the onset, development and breakdown of the vortical structures within the flat plate boundary layer. Moreover, the effect of one spanwise array of holes with diameter of 0.2λ (=3 mm) was examined. This investigation was done on two different flat plates with holes placed at the location x/λ = 2 downstream of the troughs and peaks. The presence of holes after troughs does not show any significant effect on the vortical structures. However, the plate with holes after peaks noticeably delays the vortex breakdown. In this case, the “mushroom-like” vortices move away from the wall and propagate downstream with stable vortical structures. The vortex growth is halted further downstream but start to tilt aside.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 359-367 |
| Number of pages | 9 |
| Journal | Journal of Visualization |
| Volume | 19 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 5 2016 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: The authors would like to thank all the laboratory technologists in the Fluid Mechanics Laboratory, Department of Mechanical Engineering, National University of Singapore for their help in conducting the experiments and also Dr. Yann Bouremel of Institute of Ophthalmology, University College, London, UK for his help and advice in flow visualization.