| Title |
A Study on the Characteristics of Two-Phase Flow by Driven Bubbles |
| Keywords |
Electro-conductivity probe ; 전기전도도 프로브 ; Local volume fraction ; 국부 기체체적률 ; Bubble frequency ; 기포빈도수 ; Thermo vision camera ; 열화상카메라 |
| Abstract |
In the present study, the characteristics of upward bubble flow were experimentally investigated in a liquid bath. An electro-conductivity probe was used to measure local volume fraction and bubble frequency. Since the gas is concentrated at the near nozzle, the flow parameters are high near the nozzle. In general their axial and radial values tended to decrease with increasing distance. For visualization of flow characteristics, a Particle Image Velocimetry(P.I.V) and a thermo-vision camera were used in the present study. The experimental results show that heat transfer from bubble surface to water is largely completed within10mm from the nozzle, and then the temperature of bubble surface reaches that of water rapidly. Due to the centrifugal force, the flow was more developed near the wall than at bubble-water plume. Vortex flow in the bottom region was relatively weaker than that in the upper region. |