Scaling of the bubble formation in a flow-focusing device: Role of the liquid viscosity
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- 作者：Yutao Lu ; Taotao Fu ; Chunying Zhu ; Youguang Ma ; Huai Z. Li
- 关键词：Bubble ; Complex fluids ; Hydrodynamics ; Interface ; Multiphase flow
- 刊名：Chemical Engineering Science
- 出版年：24 February, 2014
- 年：2014
- 卷：105
- 期：Complete
- 页码：213-219
- 全文大小：1303 K
文摘
The present work studies the bubble formation in viscous liquids with the viscosity ranging from 5 to 400 mPa s by using a high-speed digital camera. The experiment was carried out in a flow-focusing device with square cross-section of 600脳600 渭m. Results show that the viscous shear stress strongly influences the dynamics of bubble formation, including the shape and size of bubbles. The bubble size follows power-law relations with the gas flow rate, the flow rate and viscosity of the liquid phase respectively, indicating that bubbles formed in viscous fluids are controlled by a combination of squeezing mechanism and shearing mechanism. Therefore, the bubble size can be predicted by a power-law function depending on the flow rate ratio of gas and liquid phases 蠁 representing the squeezing mechanism and capillary number Ca representing the shearing mechanism. In addition, the dynamics of bubble formation in viscous liquids in a flow-focusing device is also analyzed.