Numerical Analysis of Magnetohydrodynamic Pump

Abstract

Magneto-hydrodynamics (MHD) offers an elegant way to control fluid flow in micro devices without a need for any mechanical components. In the presence of an external magnetic field, the judicial interaction between the electric currents and magnetic fields results Lorentz forces in a microchannel filled with ionic sample solutions and patterned with electrodes on the opposing walls. The resulted Lorentz forces can be used to propel, stir, mix and/or manipulate fluid in the channel. So far, many works are reported about the MHD micro channels for various applications. There is still a need for better understanding of flow behavior in these microdevices. Also, there are insufficient studies of flow phenomenon under MHD in microtubules. In this thesis, microchannels are designed and modeled to run 3D fluid flow simulation for MHD investigation. Rectangular microchannels' geometries in the order of micrometers were created, preprocessed, simulated and postprocessed in COMSOL, a commercially available finite element software. COMSOL is used here to model the fluid flow through Navier-Stokes and chemical ion transport through Nernst-Planck principles. With and without the application of external magnetic field, the fluid flow rate through the exit port was observed higher for B=0.44T than without any magnetic field for B=0. In presence and absence of external magnetic fields, an extensive parametric study was performed in order to find out the cross dependencies within the various experimental parameters. Logical and numerical conclusions were drawn from this study to prove the concept of MHD for manipulating fluid flow parameters in tubular microchannels. Simulating results were compared and found in a good agreement with published data in order to validate the computational study aforementioned.