J. Braz. Soc. Mech. Sci. & Eng. vol.29 número3

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In this paper, we report on numerical simulations of incompressible

MagnetoHydroDdynamic flows by a two dimensional finite difference scheme associated to an appropriate projection method performed to characterize velocity pressure formulations along the specified MHD duct by solving the set of differential equations of magnetohydrodynamics. In the present calculation, a working electrolytic solution is considered in order to bring up the application of the magnetohydrodynamic micropump. Numerical results show the characteristics of flow velocity, pressure distribution and their convergence tests. The computations aim to optimize the flow rate of a given MHD micropump regarding to its geometrical dimensions and the external electromagnetic excitation.

: magneto hydrodynamics equations, Lorentz force, finite difference scheme, projection method, velocity pressure formulation.

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= electric field, N/C =frequency, Hz = Lorentz force, N

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= height of the electrode, m

Ha = Hartmann number, dimensionless I = electric current, A

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= distance between electrodes, m Le = total length of the MHD channel, m

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N = number of ions of speciesα in the duct p = pressure, N/m2

p = average pressure over the width of the outlet duct, N/m2 q = unit charge, 1.6 1019C

) = hydrodynamic Reynolds number, dimensionless S =cross sectional area of channel, m2

s = threshold of convergence t = time, s

t =time step, s 7 = velocity, m/s

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= axis in Cartesian coordinates y = axis in Cartesian coordinates z = axis in Cartesian coordinates

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