| Title |
Effects of an Electric Field on the Dynamic Characteristics of Bubbles in Nucleate Boiling |
| Keywords |
EHD ; 전기수력학 ; Electric field ; 전기장 ; Nucleate boiling heat transfer enhancement ; 핵비등 열전달 촉진 ; Bubble ; 기포 ; Pool boiling ; 풀비등 |
| Abstract |
In order to investigate the effects of an electric field on EHD (Electro-hydrodynamic) nucleate boiling heat transfer characteristics in a nonuniform electric field under saturated pool boiling, the basic study has been performed experimentally. In the present study, the working fluid is R-113 and the plate-wire electrode system is used to generate a steep electric field gradient. Boiling parameters are investigated by using a high speed camera. The electric field distribution around a wire is obtained to understand the effect of an electric field on bubble departure/movement. The experimental results show EHD effects are much more considerable when the applied voltage increases. Bubbles depart away from the heated wire in radial direction. It is confirmed that the mechanisms of EHD nucleate boiling are closely connected with the dynamic behavior of bubbles. The boiling parameters are significantly changed by the electric field strength. With increasing applied voltages, the bubble size decreases and the nucleation site density, bubble velocity and bubble frequency increase. |