Visualization of Traveling Vortices in the Boundary Layer on a Rotating Disk under Orbital Motion
ABSTRACT
The objective of this study is to experimentally visualize traveling vortices in the boundary layer on a rotating disk under orbital motion. The orbital radius is half of the disk’s diameter (200 mm) and the maximum speed of orbital motion is 500 revolutions per minute. The Reynolds number in the pure-rotation case is 2.77 × 105. The characteristics of two types of traveling vortices are visualized by a smoke-wire method. The first type is transition vortices. In the pure-rotation case, they arise at circumferentially equal intervals, and are not traveling but stationary relative to the rotational disk. The result of visualization of this type shows that the intervals between transient vortices change in a circumferential direction, or in an orbital radial direction, on the rotating disk under orbital motion. The second type is new arc-shaped vortices that correspond to low-frequency disturbances. As orbital speed increases, the radial traveling velocities of the low-frequency disturbances increase and the intervals between low-frequency disturbances decrease.
The objective of this study is to experimentally visualize traveling vortices in the boundary layer on a rotating disk under orbital motion. The orbital radius is half of the disk’s diameter (200 mm) and the maximum speed of orbital motion is 500 revolutions per minute. The Reynolds number in the pure-rotation case is 2.77 × 105. The characteristics of two types of traveling vortices are visualized by a smoke-wire method. The first type is transition vortices. In the pure-rotation case, they arise at circumferentially equal intervals, and are not traveling but stationary relative to the rotational disk. The result of visualization of this type shows that the intervals between transient vortices change in a circumferential direction, or in an orbital radial direction, on the rotating disk under orbital motion. The second type is new arc-shaped vortices that correspond to low-frequency disturbances. As orbital speed increases, the radial traveling velocities of the low-frequency disturbances increase and the intervals between low-frequency disturbances decrease.
Cite this paper
Munekata, M. , Kubo, K. and Yoshikawa, H. (2015) Visualization of Traveling Vortices in the Boundary Layer on a Rotating Disk under Orbital Motion. Open Journal of Fluid Dynamics, 5, 17-25. doi: 10.4236/ojfd.2015.51003.
Munekata, M. , Kubo, K. and Yoshikawa, H. (2015) Visualization of Traveling Vortices in the Boundary Layer on a Rotating Disk under Orbital Motion. Open Journal of Fluid Dynamics, 5, 17-25. doi: 10.4236/ojfd.2015.51003.
References
[1] Reed, H.L. and Saric, W.S. (1989) Stability of Three Dimensional Boundary Layers. Annual Review of Fluid Mechanics, 21, 235-284.
http://dx.doi.org/10.1146/annurev.fl.21.010189.001315 [2] Gregory, N., Stuart, J.T. and Walker, W.S. (1955) On the Stability of Three-Dimensional Boundary Layers with Application to the Flow Due to a Rotating Disk. Philosophical Transactions of the Royal Society of London, A248, 155-199.
http://dx.doi.org/10.1098/rsta.1955.0013 [3] Kohama, Y. (1984) Study on Boundary Layer Transition of a Rotating Disk. Acta Mechanica, 50, 193-199.
http://dx.doi.org/10.1007/BF01170959 [4] Schlichting, H. (1955) Boundary-Layer Theory. McGraw-Hill, New York, 83-89. [5] Von Kármán, T. (1921) über laminare und turbulnte Reibung. Zeitschrift für Angewandte Mathematik und Mechanik, 1, 233-252.
http://dx.doi.org/10.1002/zamm.19210010401 [6] Kobayashi, R., Kohama, Y. and Takamadate, Ch. (1980) Spiral Vortices in Boundary Layer Transition Regime on a Rotating Disk. Acta Mechanica, 35, 71-82.
http://dx.doi.org/10.1007/BF01190058 [7] Munekata, M., Jobi, N., Ikebe, K. and Yoshikawa, H. (2012) Effects of Orbital Motion on the Boundary Layer Flow on a Spinning Disk. Open Journal of Fluid Dynamics, 2, 181-186.
http://dx.doi.org/10.4236/ojfd.2012.24A020 [8] Munekata, M., Jobi, N., Kubo, K. and Yoshikawa, H. (2013) Characteristics of Transient Vortices in the Boundary Layer on a Rotating Disk under Orbital Motion. Journal of Thermal Science, 22, 600-605.
http://dx.doi.org/10.1007/s11630-013-0668-0 [9] Malik, M.R., Wilkinson, S.P. and Orszag, S.A. (1981) Instability and Transition in Rotating Disk Flow. AIAA Journal, 19, 1131-1138.
http://dx.doi.org/10.2514/3.7849
[1] Reed, H.L. and Saric, W.S. (1989) Stability of Three Dimensional Boundary Layers. Annual Review of Fluid Mechanics, 21, 235-284.
http://dx.doi.org/10.1146/annurev.fl.21.010189.001315 [2] Gregory, N., Stuart, J.T. and Walker, W.S. (1955) On the Stability of Three-Dimensional Boundary Layers with Application to the Flow Due to a Rotating Disk. Philosophical Transactions of the Royal Society of London, A248, 155-199.
http://dx.doi.org/10.1098/rsta.1955.0013 [3] Kohama, Y. (1984) Study on Boundary Layer Transition of a Rotating Disk. Acta Mechanica, 50, 193-199.
http://dx.doi.org/10.1007/BF01170959 [4] Schlichting, H. (1955) Boundary-Layer Theory. McGraw-Hill, New York, 83-89. [5] Von Kármán, T. (1921) über laminare und turbulnte Reibung. Zeitschrift für Angewandte Mathematik und Mechanik, 1, 233-252.
http://dx.doi.org/10.1002/zamm.19210010401 [6] Kobayashi, R., Kohama, Y. and Takamadate, Ch. (1980) Spiral Vortices in Boundary Layer Transition Regime on a Rotating Disk. Acta Mechanica, 35, 71-82.
http://dx.doi.org/10.1007/BF01190058 [7] Munekata, M., Jobi, N., Ikebe, K. and Yoshikawa, H. (2012) Effects of Orbital Motion on the Boundary Layer Flow on a Spinning Disk. Open Journal of Fluid Dynamics, 2, 181-186.
http://dx.doi.org/10.4236/ojfd.2012.24A020 [8] Munekata, M., Jobi, N., Kubo, K. and Yoshikawa, H. (2013) Characteristics of Transient Vortices in the Boundary Layer on a Rotating Disk under Orbital Motion. Journal of Thermal Science, 22, 600-605.
http://dx.doi.org/10.1007/s11630-013-0668-0 [9] Malik, M.R., Wilkinson, S.P. and Orszag, S.A. (1981) Instability and Transition in Rotating Disk Flow. AIAA Journal, 19, 1131-1138.
http://dx.doi.org/10.2514/3.7849