关键词: 电水动力学, 气泡, 非均匀电场

Abstract: In order to make further study on the electrohydrodynamic enhancement mechanisms of boiling heat transfer, the shape of boiling bubbles when departing wall in the nonuniform electric field was visually investigated with a high-speed camera. The bubble shape when departing the wall was observed in the nonuniform electric field. The bubbles leaving the wall were basically spherical in shape without the high voltage electric field. The bubbles leaving the wall were elliptical in shape in electric field. When electric field strength was increased, the bubble elongation along the field direction was more obvious. The growth of bubbles was mainly affected by the inertial force and surface tension control without electric field. When electric field was applied, the bubble force increased by the action of electric field force. Electrical stress in the equatorial direction compressed the bubbles in the polar axis direction tensile bubble. Under the action of the electric field, the bubbles were changed from spherical to ellipsoidal in shape. As the field strength increased, the bubble by electrical stress increased, the bubble detachment wall along the field direction of elongation became more obvious. When the voltagewas applied, the bubble detachment frequency increased with the field strength. When the electric field intensity was at 1.4 kV/mm, the bubble detachment frequency was as 1.85 times higher, compared to the situation without electric field. The experimental results showed that electric fields had obvious effects on the behavior of the bubbles.

Key words: electrohydrodynamic, bubble, nonuniform electric fields