Predication of bubble sliding velocity under rolling motion condition

The increasing mixing leads by the wake generated behind the sliding bubble can enhance heat transfer of the heated wall. Bubble sliding velocity may be affected by the varied force field caused by rolling motion. Bubble sliding experiment is carried out under rolling motion condition in order to study the influence of the periodical additional inertial force. The experimental results shows that the bubble siding velocity changes periodically with the same period of the rolling motion. A predication model is established based on the bubble forces under rolling motion. Several reasonable simplification process is adopted in the model. Bubble growth force is ignored in the model for the reason that the diameter of the bubble changes slowly and thereby produces negligible effects compared with the other forces. A good agreement between predicted and measured results is achieved. (author)