Investigation of Electrohydrodynamic Effect on Free Convection Heat Transfer Coefficient by Computational Fluid Dynamic

چکیده مقاله

Free convection heat transfer in the ethylene glycol around a thin platinum wire in the presence of an electric field is studied in the present study using computational fluid dynamics. Free convection heat transfer coefficient changes in different intensities of the electric field, as well as the effect of number and deformation of electrode on heat transfer was studied and compared with experimental results. The results indicated that electrohydrodynamic with low power consumption increases the free convection heat transfer coefficient. Increase of rate in the heat transfer coefficient in the presence of an electric field in the low Rayleigh number is higher than high Rayleigh number, because in the high Rayleigh number effect of secondary flow against the flow generated from the buoyancy force is reduced. Free convection heat transfer coefficient of ethylene glycol in the presence of an electric field created by three needle electrodes with voltage of 12.5 kV in low Rayleigh number is increased up to 37%, and at high Rayleigh numbers up more than 4%. Also, heat transfer coefficient has increased using a needle electrode, but its value is less than the time when three needle electrodes are used. By replacing the needle electrodes with a plate electrode, as a result of further secondary flow, free convection heat transfer coefficient is further increased.

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