%0 Journal Article %A Wang, Guoshan %A Bao, Ran %D 2011 %I Begell House %K enhanced heat transfer, electrohydrodynamics, convective heat transfer, oil %N 2 %P 107-114 %R 10.1615/JEnhHeatTransf.v18.i2.20 %T HEAT TRANSFER AUGMENTATION OF A TRANSFORMER OIL FLOW IN A SMOOTH TUBE BY EHD EFFECT UNDER HIGH TEMPERATURES %U https://www.dl.begellhouse.com/journals/4c8f5faa331b09ea,3a58938b34f636c7,0729b8f72ac27874.html %V 18 %X An experimental investigation was performed to understand the electrohydrodynamic (EHD) enhancing effect on laminar forced convective heat transfer of transformer oil. The experiment was carried out in a horizontally positioned smooth tube with an inner diameter of 30 mm under high-temperature conditions. Experimental results show that a high electric voltage applied can exert a strong enhancing effect on the heat transfer, but will cause only small augmentation on the friction factor. The heat transfer enhancement increases rapidly with the increase of the electric voltage applied, and then it seems gradually to approach a saturated maximum value. Also, the oil temperature has a great influence on the heat transfer enhancement and the enhancement ratio increases with the increase of the oil temperature. The average enhancement ratio of the heat transfer coefficient can exceed 6 under 8.0 kV voltages applied, while that of the average friction factor approaches only 1.5. %8 2011-04-20