Thermocapillary Bubble Oscillations and Migration in a Vibrating Cylinder in a Zero?Gravity Environment

摘要

Bubble migration in a vibrating zero gravity environment is numerically investigated using ANSYS-FLUENT software. A 3D CFD model is developed describing the two-phase flow of a nitrogen bubble immersed in a container full of ethanol. The Volume of Fluid (VOF) method and the geometric reconstruction scheme are used to track the gas–liquid interface. The liquid in the container is vibrated horizontally in the x momentum with different frequencies from 0 to 1 Hz, and amplitudes from 0.005 to 0.1 m/s~2. The vibration impact on the bubble arrival time to the top and its ensuing dynamic is analyzed. Different bubble trajectory shapes are observed, other than the conventional vertical translation induced by the temperature difference. Compared to the no vibration case, the bubble motion is slightly either accelerated or decelerated for very low vibration amplitudes. For a fixed frequency f = 1 Hz, the bubble takes more time to reach the top with the vibration amplitude increment relatively to the no vibration case. The vibration effect becomes more intense with the Marangoni number decrease when f = 0.2 Hz and A_b = 0.005 m/s~2. Those results are difficult to obtain experimentally, signifying the importance of this numerical study to understand bubble motion and migration in space.