Recearch Projects

Mechanisms of magneto-hydrostatic instabilities


The competition between capillary and magnetic forces due to the interaction of magnetic fields and magnetic liquids (commonly called ferrofluids) gives rise to instabilities leading to multiplicity of equilibrium states, pattern formation or system rupture. The mechanisms of the instabilities and selection scenarios are gradually illuminated through realistic large-scale computational analysis and experimentation. We currently develop tools aiming to interact with the governing mechanisms. Promotion or inhibition of specific system states is of special concern and the implementation of disturbance manipulation techniques, applied in open or in closed loop, is studied.

Selected Publications

  • C. Gollwitzer, A. N. Spyropoulos, A. G. Papathanasiou, A. G. Boudouvis and R. Richter "The normal field instability under side-wall effects: Comparison of experiments and computations." New Journal of Physics, 11, 053016, 2009.[link]
  • E. G. Megalios, N. I. Kapsalis, J. Paschalidis, A. G. Papathanasiou and A. G. Boudouvis “A simple optical device for measuring free surface deformations of non-transparent liquids” Journal of Colloid and Interface Science,288, 508, 2005. [link]
  • A. G. Papathanasiou and A. G. Boudouvis “Wetting effects on magneto-hydrostatics of rotating ferrofluid drops: Experimental and computational analysis” Journal of Magnetism and Magnetic Materials, 252, 262, 2002. [link]
  • A. G. Papathanasiou and A. G. Boudouvis “Three-lobe-shaped equilibrium states in magnetic liquid bridges”Physical Review E, 65, 035302, 2002. [link]
  • A. G. Papathanasiou and A. G. Boudouvis “Pre-labyrinthine, cross-sectional instabilities of captive ferrofluid drops: computations and experiments” Magnetohydrodynamics, 35, 314, 1999. [link]
  • A. G. Papathanasiou and A. G. Boudouvis “Three-dimensional magnetohydrostatic instabilities of rotating ferrofluid drops” Journal of Magnetism and Magnetic Materials, 201, 290, 1999. [link]
  • A. G. Papathanasiou and A. G. Boudouvis “Three-dimensional instabilities of ferromagnetic liquid bridges”Computational Mechanics, 21, 403, 1998. [link]

Funding

  • "Normal and tilted field instability in pools of ferrofluid: experiments-computation-theory"
    Program for the Promotion of the Exchange and Scientific Cooperation between Greece and Germany - Program“IKYDA”, 2007-2008. Principal Investigator: A. G. Boudouvis, NTUA. Senior Researcher: A. G. Papathanasiou. Partners: School of Chemical Engineering of the NTUA and Physics Department of the University of Bayreuth (Dr R. Richter).
  • "Mechanisms of pattern selection in magnetic liquids: large-scale computational analysis and experiments"
    Institute of Communication and Computer Systems of NTUA, Basic Research Program "ΑΡΧΙΜΗΔΗΣ", 2000-02. Principal Investigator: A. G. Boudouvis, NTUA.
  • "A new generation of dynamic simulators: Scientific computations of stability, bifurcation, functionality and control for distributed parameter systems" 
    General Secretariat for Research and Technology, Program "ΠENEΔ", 2000-2001. 
    Principal Investigators: I. G.  Kevrekidis, Univ. Patras/Princeton, A. G. Boudouvis, NTUA and C. Makridakis, Univ. Crete.
  • "Software development/adaptation and implementation for magnetohydrodynamic stability analysis with parallel processing"
    General Secretariat for Research and Technology, Program "ΠENEΔ", 1996-98.
    Principal Investigator: A. G. Boudouvis, NTUA.