Sizes of bubbles produced by dissolved gas coming out of solution on the walls of pipes in flowing systems
✍ Scribed by R.H.S. Winterton
- Publisher
- Elsevier Science
- Year
- 1972
- Tongue
- English
- Weight
- 665 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0009-2509
No coin nor oath required. For personal study only.
✦ Synopsis
In a liquid that is sufficiently supersaturated with dissolved gas bubbles will form at nucleating cavities on the containing walls. In this paper equations are derived for the drag and surface tension forces on gas bubbles adhering to the walls of pipes in flowing systems. The equations are used to predict the bubble radius on detachment, and give good agreement with some experimental results for finite contact angles.
The drag force is calculated using values of the drag coefficient obtained from experiments on the terminal velocity of freely rising bubbles and the velocitv profile for fullv develoned turbulent flow in a circular pipe. The surface tension force opposing the-d-rag force arises from ihe different contact angles upstream and downstream of the bubble. If the liquid exhibits a zero contact angle on the surface the surface tension force is determined by the radius of the nucleating cavity. A method of calculating this radius from superheat or cavitation data is described.