Wetting and Capillarity Effects on Bubble Formation From Orifice Plates Submerged in Pools of Water
- 8 September 2021
- journal article
- research article
- Published by ASME International in Journal of Heat Transfer
- Vol. 143 (10)
- https://doi.org/10.1115/1.4051321
Abstract
An experimental study of bubble growth from submerged orifice plates in pools of water is carried out to scale and correlate the effects of surface wettability and orifice diameter D0 on ebullience. Measurements of bubble growth on surfaces with nine different contact angles (38° ≤ θ ≤ 128°) with varying air flow rates (1 to 300 ml/min) were made using high speed videography and image processing. In the static or constant-volume regime, below a critical contact angle θc, the bubble base remains attached to the orifice and the equivalent departure diameter Db is independent of contact angle θ. On the other hand, above the critical contact angle, the bubble base spreads on the surface resulting in larger Db. For θ > θc, Db is strongly dependent on θ and increases with it. Using minimum energy method, it is shown that the wettability effects can be scaled and correlated by a modified capillary length, defined as a function of the Laplace length and contact angle. The proposed correlation provides predictions of Db that agree with experimental data of this study as well as those available in the literature to within ±15 %. Moreover, for a hydrophobic surface when D0 > twice the modified capillary length, the bubble grows inside the orifice; for a hydrophilic surface this scales with twice the capillary length and effect of θ is not seen.Keywords
This publication has 23 references indexed in Scilit:
- Molecular-to-Large-Scale Heat Transfer With Multiphase Interfaces: Current Status and New DirectionsJournal of Heat Transfer, 2009
- Air-Water Ebullience Systems: Visualizing Single Bubble to Wave Instability SignaturesJournal of Heat Transfer, 2008
- Experimental Investigations of Regimes of Bubble Formation on Submerged Orifices Under Constant Flow ConditionThe Canadian Journal of Chemical Engineering, 2007
- Numerical simulation of periodic bubble formation at a submerged orifice with constant gas flow rateChemical Engineering Science, 2007
- On the Advancements in Boiling, Two-Phase Flow Heat Transfer, and Interfacial PhenomenaJournal of Heat Transfer, 2006
- Bubble Formation and Bubble Rise Velocity in Gas−Liquid Systems: A ReviewIndustrial & Engineering Chemistry Research, 2005
- Quasi-static bubble formation on submerged orificesInternational Journal of Heat and Mass Transfer, 2005
- Aperiodic bubble formation from a submerged orificeChemical Engineering Science, 2001
- Numerical investigation of bubble growth and detachment by the lattice-Boltzmann methodInternational Journal of Heat and Mass Transfer, 2001
- Modes of bubble growth in the slow-formation regime of nucleate pool boilingInternational Journal of Multiphase Flow, 1978