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This research paper explores the dynamics, equilibrium, and stability of a liquid column between unequal discs. It analyzes the time evolution, equilibrium shapes, and kinetic parameters using automated image edging and axial dynamics. The study reveals unexpected oscillating behaviors with small non-decaying amplitude and close frequency to the natural frequency. The limitations of scarce experimental time and unknown boundary conditions are addressed. While automated image analysis has advanced, some details of the discs remain unclear. Digital imaging offers potential solutions to overcome previous video limitations.
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WOBBLING OF A LIQUID COLUMN BETWEEN UNEQUAL DISCS I. Martínez, J. Meseguer, J.M. Perales IDR/UPM, Universidad Politécnica de Madrid, Madrid, Spain COSPAR 2004 Monday, 19th July 2004
Equilibrium and stability of the columnGeometrical parameters
Equilibrium shapes and their stability criterion • Equilibrium shape • Stability limit
Dynamics • Axial dynamics of quasi-cylindrical liquid columns
Conclusions • Long liquid columns are very sensitive to disturbances, and theories are available to analyse in detail the liquid response • Dynamic effects grow when sensitivity increases • Actual liquid column shapes appear oscillating: • Around an equilibrium shape that is unexpected (a residual load shows up) • With a small but non-decaying amplitude (0.5 mm against 14.5 mm) • With a frequency very close to the natural frequency (a period of 12 s) • Useful experimental time is very scarce (a couple of minutes in half an hour, here) • Unique experiments may have some boundary conditions unknown (these experiments have not been reproduced yet) • Automated image analysis has progressed a lot, but small problems remain (we benefit from overall analysis, but details of the discs are not visible) • Digital imaging nowadays would solve many of the old video problems