Summary
The linearized stability analysis is applied to investigate the wave behavior in a water vortex produced in a cylindrical tank with a flat disk rotating at the bottom. Two flow cases are considered herein. The first case deals with waves developed on the free surface of a hollow vortex, while the second with waves generated in the core of a Rankine vortex. It is evident from the analysis that the experimental dispersion velocity approaches the calculated one when the wave amplitude becomes smaller. The latter is consistent with the small perturbation assumption that is inherent in the theory. For the case where the core is flooded, the presence of a cylindrical wall is shown to enhance the wave speed. A hypothesis as to how the core develops in the mixed state regions is proposed. The graphical simulations appear to predict reasonably well the main features of the observations.
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Abbreviations
- a :
-
radius of the liquid surface whenz=0
- h 0 :
-
initial liquid height
- m :
-
slope of the tangential velocity in [o,r c]
- P :
-
static pressure
- n :
-
wave number
- r, φ,z, t :
-
radial, azimuthal, axial and time coordinates
- r c :
-
core radius
- r i :
-
cylindrical tank radius
- r e, ze :
-
radius and elevation of the free surface
- u, v :
-
velocity components (inr and φ directions respectively)
- χ:
-
vortex strength of the base flow
- v :
-
kinematic viscosity of the fluid
- ϑ:
-
liquid density
- σ:
-
angular frequency
- Φ:
-
velocity potential
- Φ :
-
disk speed
References
Vatistas, G. H.: A note on liquid vortex sloshing and Kelvin's equilibria. J. Fluid Mech.217, 241–248 (1990).
Thomson, W. (Lord Kelvin).: Vibrations of a vortex column. Phil. Mag.10, 155–168 (1880); also in: Gray, A., Mathews, G. B.: A treatise on Bessel functions and their applications to Physics, p. 118. London: MacMillan 1922.
Vatistas, G. H., Wang, J., Lin, S.: Experiments on waves induced in the hollow core of vortices. Exp. Fluids13, 377–385 (1992).
Sawatzki, O., Zierep, J.: Das Stromfeld im Spalt zwischen zwei konzentrischen Kugelflächen, von denen die innere rotiert. Acta Mech.9, 13–15 (1970). Also in: ZAMM50, 205–208 (1970).
Zierep, J.: Analogies between thermal and viscous instabilities. In: Convective transport and instability phenomena (Zierep, J., Oertel, H. Jr., eds.) pp. 25–37. Karlsruhe: G. Braun 1982.
Burkhalter, J. E., Koschmieder, E. L.: Steady supercritical Taylor vortices after sudden starts. Phys. Fluids17, 1929–1939 (1974).
Busse, F. H.: Non-linear properties of thermal convection. Rep. Prog. Phys.41, 1929–1969 (1978).
Gregory, N., Stuart, J. T., Walker, W. S.: On the stability of three-dimensional boundary layers with application to the flow due to a rotating disk. Phil. Trans. Roy. Soc. London Ser. A248, 155–199 (1955).
Mason, B. J.: Global atmospheric research programme. Nature233, 382–388 (1971).
Markus, S.: The mechanics of vibrations of cylindrical shells. In: Studies in applied mechanics 17, p. 16. New York: Elsevier 1988.
Holter, N.J., Glasscock, W.R.: Vibrations of evaporating drops. J. Acoust. Soc. Am.24, 683–685 (1952).
Schneider, M. H., Snell, R. F., Tracy, J. J., Powers, D. R.: Buckling and vibration of externally pressurized conical shells with continuous and discontinuous rings. AIAA J.29, 1515–1522 (1991).
Lamb, H.: Gydrodynamics, 6th ed., p. 230. Cambridge: Cambridge University Press 1932.
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Vatistas, G.H., Wang, J. & Lin, S. Recent findings on Kelvin's equilibria. Acta Mechanica 103, 89–102 (1994). https://doi.org/10.1007/BF01180220
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DOI: https://doi.org/10.1007/BF01180220