Abstract
A numerical study is made of the spin-up from rest of a three-layer fluid in a closed, vertically-mounted cylinder. The densities in the upper layer ρ1 middle layer ρ2 and lower layer ρ3 are ρ3>ρ2>ρ1, and the kinematic viscosities are left arbitrary. The representative system Ekman number is small. Numerical solutions are obtained to the time-dependent axisymmetric Navier-Stokes equations, and the treatment of the interfaces is modeled by use of the Height of Liquid method. Complete three-component velocity fields, together with the evolution of the interface deformations, are depicted. At small times, when the kinematic viscosity in the upper layer is smaller than in the middle layer, the top interface rises (sinks) in the central axis (peripheral) region. When the kinematic viscosity in the lower layer is smaller than in the middle layer, the bottom interface rises (sinks) in the periphery (axis) region. Detailed shapes of interfaces are illustrated for several cases of exemplary viscosity ratios.
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Abbreviations
- A:
-
Aspect ratio, R/H [—]
- Fr:
-
Froude number, (ΩR)2/gH [—]
- g:
-
Gravity [m/s2]
- E:
-
Ekman number, v/Ωf R 2 [—]
- H:
-
Height of cylinder [m]
- h0 :
-
The original height at the initial state [m]
- R:
-
Radius of cylinder [m]
- Re:
-
Reynolds number, Ωf R 2/v [—]
- p:
-
Dimensionless pressure [—]
- u* :
-
Reference velocity, ΩR [m/s]
- t:
-
Time [s]
- (Vγ, Vϕ, Vz :
-
Dimensionless velocity components corresponding to (γ, —, z)
- (γ, —, z):
-
Dimensionless (radial, azimuthal, vertical) coordinates in cylindrical system
- (α, β, γ):
-
Indicators [ — ]
- Ω:
-
Rotation rate [s-1]
- υ:
-
Kinematic viscosity [m2/s]
- υ1,υ2 :
-
Kinematic viscosity ratios, υ1 = υ1*/υ3* υ2 = υ2*/υ3* [—]
- ρ:
-
Dimensionless density, ρ*/p3 [—]
- ρ1,ρ2 :
-
Density ratios, ρ1 = ρ1/ρl ρ2 = ρ2/ρ3 [—]
- τ:
-
Dimensionless time, tΩ [—]
- ψ:
-
Dimensionless meridional stream function [—]
- 1:
-
Values in upper layer
- 2:
-
Values in middle layer
- 3:
-
Values in lower layer
- f:
-
Final state
- i:
-
Initial state
- *:
-
Dimension values
References
Baker, G. R. and Israeli, M., 1981, “Spin-Up from Rest of Immiscible Fluids,”Studies in Applied Mathematics, Vol. 65, pp. 249~268.
Brackbill, J., Kothe, D. B. and Zemach, C., 1992, “A Continuum Method for Modeling Surface Tension,”J Comput. phys., 100, pp. 335~354.
Flor, J. B., Ungarish, M. and Bush, J. W. M., 2002, “Spin-up from Rest in a Stratified Fluid: Boundary Flows,”Journal of Fluid Mechanics, 472, pp. 51~82.
Greenspan, H. p. and Howard, L. N, 1963, “On a Time Dependent Motion of a Rotating Fluid,”Journal of Fluid Mechanics, Vol. 17, part 3, pp. 385~404.
Greenspan, H. p., 1968, “The Theory of Rotating Fluids,”Cambridge, UK:Cambridge Univ. press., 327 pp.
Kim, K. Y. and Hyun, J. M., 1994, “Spin-up From Rest of a Two-layer Liquid in a Cylinder,”J of Fluid Engineering, 116, pp. 808~814.
Lim, T. G., Choi, S. and Hyun, J. M., 1993, “Transient Interface Shape of a Two-layer Liquid in an Abruptly Rotating Cylinder,”J of Fluid Engineering, 115, pp. 324~329.
Nichols B.D. and Hirt C. W., 1971, “Calculating Three-Dimensional Free Surface Flows in the Vicinity of Submerged and Exposed Structures,”J Comp. phys., 12, 234.
Patankar S. V., 1980, “Numerical Heat Transfer and Fluid Flow,” Hemisphere, Washington, DC.
Wedemeyer, E. H., 1964, “The Unsteady Flow within a Spinning Cylinder,”Journal of Fluid Mechanics, Vol. 20, part 3, pp. 383~399.
Weidman, P.D., 1976, “On the Spin-Up and Spin-Down of a Rotating Fluid. part I: Extending the Wedemeyer Model. part II : Measurements and Stability,”Journal of Fluid Mechanics, Vol.77, part 4, pp. 685~735.
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Sviridov, E., Hyun, J.M. Flow characteristics in spin-up of a three-layer fluid. J Mech Sci Technol 20, 271–277 (2006). https://doi.org/10.1007/BF02915829
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DOI: https://doi.org/10.1007/BF02915829