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PROCEEDINGS OF THE SEVENTH INTERNATIONAL CONFERENCE ON ENGINEERING COMPUTATIONAL TECHNOLOGY
Edited by: B.H.V. Topping, J.M. Adam, F.J. Pallarés, R. Bru and M.L. Romero
Direct Current Magnetic Levitation of a Liquid Droplet: Numerical Solutions
V. Bojarevics, S. Easter and K. Pericleous
School of Computing and Mathematical Sciences, University of Greenwich, London, United Kingdom
V. Bojarevics, S. Easter, K. Pericleous, "Direct Current Magnetic Levitation of a Liquid Droplet: Numerical Solutions", in B.H.V. Topping, J.M. Adam, F.J. Pallarés, R. Bru, M.L. Romero, (Editors), "Proceedings of the Seventh International Conference on Engineering Computational Technology", Civil-Comp Press, Stirlingshire, UK, Paper 71, 2010. doi:10.4203/ccp.94.71
Keywords: magnetic levitation, high direct current magnetic field, material properties measurement, computational fluid dynamics, magnetohydrodynamics, free surface.
A high DC magnetic field can be used to levitate liquid droplets in terrestrial conditions, as is known from experiments [1,2]. The DC magnetic levitation mechanism is considerably different from the AC case , where an intense turbulent flow is generated as a consequence of the rotational nature of the electromagnetic force. In DC magnetic levitation the force distribution is a potential function, which permits analytical solutions in particular cases . The dynamic interactions of the flow with the oscillating interface, confined by the magnetic force, are analysed using a multi-physics numerical model for simulating the time dependent liquid metal and the magnetic field generated by currents in the coil system . The numerical simulations demonstrate the possibility of levitating diamagnetic droplets in strictly controllable conditions permitting the material properties measurement from experimental observations.
Two different coil arrangements are analysed using the numerical code to model the DC magnetic levitation of a water droplet. The levitation of liquid in controllable conditions is achievable but requires careful optimisation of the electromagnetic and gravity force balance. The fluid velocities, generated by the magnetic force modification due to the liquid surface oscillation in the strong gradient field, are small in magnitude and remain in the laminar regime.
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