Abstract:

The formation of a nitrogen bubble under adiabatic condition in the electric field was visually investigated.The bubble’s dynamic growth was observed in the electric field.The bubble elongated along the direction of the electric field.With increasing electric field strength，the bubble’s aspect ratio at the departure increased while the departure volume decreased.The bubble contours were extracted from the experimental images by means of Matlab toolboxes.The electric stresses on the actual bubble surface were calculated，which indicated that the electric stress exerted on the bubble tip pulled the bubble while that exerted on the bubble sides pressed the bubble，causing the bubble elongation deformation along the electric field direction.The bubble deformation resulted primarily from the effect of the electric stresses acting on the bubble surface.It helps to analyze further the effects of electric field on nucleate boiling heat transfer.