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 OJFD  Vol.7 No.2 , June 2017
Effects of Orbital Motion on the Velocity Field of Boundary Layer Flow over a Rotating Disk
Abstract: The purpose of this study is to investigate experimentally the effects of orbital motion on the velocity field of boundary layer flow over a rotating disk. The characteristics of velocity field at a fixed orbital angular section measured by a hot-wire anemometer show that the structure of the 3-dimensional boundary layer flow is deformed elliptically and displaced in a certain direction that is not in the orbital radial direction, but the direction of deformation depends on the combination of orbital and rotational directions. For coincide orbital and rotational directions, there are regions where the intensity of low-frequency disturbances increases rapidly in a certain central region (laminar region under pure rotation). The transient vortices, which form streaks on the coating film, are considered to be destroyed by low-frequency disturbances. However, for opposite orbital and rotational directions, the low-frequency disturbances are not observed in any section. As the adding orbital speed increases, the intensity of velocity fluctuations in the turbulence region becomes larger in the expected except in a certain region. This location of the region also depends on the direction of deformation or the combination of orbital and rotational directions.
Cite this paper: Munekata, M. , Utatsu, T. , Yoshikawa, H. and Okumura, Y. (2017) Effects of Orbital Motion on the Velocity Field of Boundary Layer Flow over a Rotating Disk. Open Journal of Fluid Dynamics, 7, 169-177. doi: 10.4236/ojfd.2017.72011.
References

[1]   Schlichting, H. (1955) Boundary Layer Theory. MCGRAW-HILL, New York, 193-199.

[2]   Reed, H.L. and Saric, W.S. (1989) Stability of Three Dimensional Boundary Layers. Annual Review of Fluid Mechanics, 21, 235-284. https://doi.org/10.1146/annurev.fl.21.010189.001315

[3]   Gregory, N.J., Stuart, 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.
https://doi.org/10.1098/rsta.1955.0013

[4]   Kohama, Y. (1984) Study on Boundary Layer Transition of a Rotating Disk. Acta Mechanica, 50, 193-199. https://doi.org/10.1007/BF01170959

[5]   Imayama, S., Alfredsson, P.H. and Lingwood, R.J. (2014) On the Laminar Turbulent Transition of the Rotating-Disk Flow: the Role of Absolute Instability. Journal of Fluid Mechanics, 745, 132-163. https://doi.org/10.1017/jfm.2014.80

[6]   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, 187-194. https://doi.org/10.4236/ojfd.2012.24A020

[7]   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. J. Thermal Science, 22, 600-605. https://doi.org/10.1007/s11630-013-0668-0

[8]   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. https://doi.org/10.4236/ojfd.2015.51003

[9]   Itoh, N. (1998) Theoretical Description of Instability Waves in Flow on a Rotating Disk. Transactions of the Japan Society for Aeronautical and Space Sciences, 40, 262-279.

 
 
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