Typical peculiarities of transition from regular two-dimensional to three-dimensional wave motion on vertically falling liquid films

1
Typical peculiarities of transition from regular
two-dimensional to three-dimensional wave motion
on vertically falling liquid films

• S. V. Alekseenko, V. V. Guzanov, S. M. Kharlamov
  and D. M. Markovich
• Kutateladze Institute of Thermophysics Siberian
  Branch, Russian Academy of Sciences
• Novosibirsk State University

VI SOLITONS, COLLAPSES AND TURBULENCE Achievement
s, Developments and Perspectives" June 4-8, 2012,
Novosibirsk
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Intorduction
Natural flow
Artificial perturbation of excited 2D waves

• Shadowgraph technique
• Absence of information about amplitudes

C. D. Park and T. Nosoko. Three-Dimensional Wave
Dynamics on a Falling Film and Associated Mass
Transfer. AIChE Journal. 2003. Vol. 49, No. 11.
pp. 2715 2727
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Intorduction

• Calculation
• Volume of Fluid method in conjunction with the
  Continuum Surface method
• Periodic boundary conditions
• Small computational domain

Re 59.3 ? 3940.2

• Dietze G. F., Kneer R. Flow separation in falling
  liquid films // Frontiers in Heat and Mass
  Transfer (FHMT) -2011. V. 2. ? 3. P.033001. 14 p.

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Sketch of experimental setup and operating
conditions
Water-glycerol solutions ? 106, m2/s ?, kg/m3 s, kg/s2 ?
WGS 3.9 1110 0.073 494
Water 0.94 998 0.072 3660
Kapitsa number

• For water Re18 70 (Req/?, where q specific
  flow rate, ? kinematic viscosity).
• For WGS Re10 50.
• Laser Induced Fluorescence (LIF) technique.
• Stroboscopic photography.
• Excitation of 2D waves by periodic flow rate
  modulation with frequencies f.
• Comb with equally-spaced needles for the
  perturbation of 2D waves.
• Total error 2 3.

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Natural transition
Time-averaged thickness
Instant film thickness distribution


-

• Water. Re 50, f 17Hz.

Wake formation.
Sufficient redistribution for isothermal film flow
Natural transition is observed for water for
Regt30 for WGS for Regt12
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Forced transition
WGS, Re36, f16Hz, l2.5cm
Water, Re40, f16Hz, l2cm






decrease
increase
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Forced transition
Water, Re19, f11.5Hz, l2cm



Stable propagation
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Forced transition
Experiment
Horseshoe shape
Calculation
Non-horseshoe shape
Water Re65 ?3660 f16Hz l2cm
Re59.3 ?3940.2 f17Hz l2cm
Dietze G. F., Kneer R. Flow separation in falling
liquid films // Frontiers in Heat and Mass
Transfer (FHMT) -2011. V. 2. ? 3. P.033001. 14 p.
9
Conclusion

• The cases of 2D-3D transition due to natural
  transverse instability of 2D waves and forced
  transition due to destruction of 2D waves were
  investigated experimentally.
• Natural 2D-3D transition is observed when Regt30
  for water and when Regt12 for WGS.
• Sufficient redistribution of liquid in transverse
  direction in process of 2D-3D transition for
  isothermal film flow has been revealed. For
  investigated regimes time-averaged local film
  thickness can differs up to 30 40 on the
  transverse distances compatible with transverse
  size of jets.