Local bubble size distribution, gas–liquid interfacial areas and gas holdups in an up-flow ejector

2010 ◽  
Vol 65 (18) ◽  
pp. 5264-5271 ◽  
Author(s):  
Shi-qing Zheng ◽  
Yun Yao ◽  
Fang-fei Guo ◽  
Rong-shan Bi ◽  
Jing-ya Li
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Size Distribution ◽  
Local Bubble ◽  
Interfacial Areas

Local bubble-size distribution in fluidized beds

AIChE Journal ◽  
2000 ◽  
Vol 46 (7) ◽  
pp. 1340-1347 ◽  
Author(s):  
D. Santana ◽  
A. Macías-Machín
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Fluidized Beds ◽  
Bubble Size Distribution ◽  
Local Bubble

General method for the transformation of chord-length data to a local bubble-size distribution

AIChE Journal ◽  
1996 ◽  
Vol 42 (10) ◽  
pp. 2713-2720 ◽  
Author(s):  
Weidong Liu ◽  
Nigel N. Clark ◽  
Ali Ihsan Karamavruc
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Size Distribution ◽  
Chord Length ◽  
Local Bubble ◽  
Length Data ◽  
General Method

Hybrid Eulerian Eulerian Discrete Phase Model of Turbulent Bubbly Flow

2017 ◽  
Author(s):  
Hyunjin Yang ◽  
Surya P. Vanka ◽  
Brian G. Thomas
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubbly Flow ◽  
Bubble Size Distribution ◽  
Turbulent Dispersion ◽  
Phase Model ◽  
Discrete Phase Model ◽  
Local Bubble ◽  
Discrete Phase ◽  
Bubble Sizes

The Eulerian-Eulerian two-fluid model [1] (EE) is the most general model in multiphase flow computations. One limitation of the EE model is that it has no ability to estimate the local bubble sizes by itself. Thus, it must be complemented either by measurements of bubble size distribution or by additional models such as population balance theory or interfacial area concentration to get the local bubble size information. In this work, we have combined the Discrete Phase model (DPM) [2,8] to estimate the evolution of bubble sizes with the Eulerian-Eulerian model. The bubbles are tracked individually as point masses, and the change of bubble size distribution is estimated by additional coalescence and breakup modeling of the bubbles. The time varying bubble distribution is used to compute the local interface area between gas and liquid phase, which is used to estimate the momentum interactions such as drag, lift, wall lubrication and turbulent dispersion forces. This model is applied to compute an upward flowing bubbly flow in a vertical pipe and the results are compared with previous experimental work of Hibiki et al. [3]. The newly developed hybrid model (EEDPM) is able to reasonably predict the locally different bubble sizes and the velocity and void fraction fields. On the other hand, the standard EE model without the DPM shows good comparison with measurements only when the prescribed constant initial bubble size is accurate and does not change much.

Physiochemical properties and reproducibility of air-based sodium tetradecyl sulphate foam using the Tessari method

2016 ◽  
Vol 32 (6) ◽  
pp. 390-396 ◽  
Author(s):  
Mike R Watkins ◽  
Richard J Oliver
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Size Distribution ◽  
Foam Density ◽  
Physiochemical Properties ◽  
Significant Difference ◽  
Experienced Operator ◽  
Sodium Tetradecyl Sulphate ◽  
Foam Production ◽  
Made In

Objectives The objectives were to examine the density, bubble size distribution and durability of sodium tetradecyl sulphate foam and the consistency of production of foam by a number of different operators using the Tessari method. Methods 1% and 3% sodium tetradecyl sulphate sclerosant foam was produced by an experienced operator and a group of inexperienced operators using either a 1:3 or 1:4 liquid:air ratio and the Tessari method. The foam density, bubble size distribution and foam durability were measured on freshly prepared foam from each operator. Results The foam density measurements were similar for each of the 1:3 preparations and for each of the 1:4 preparations but not affected by the sclerosant concentration. The bubble size for all preparations were very small immediately after preparation but progressively coalesced to become a micro-foam (<250 µm) after the first 30 s up until 2 min. Both the 1% and 3% solution foams developed liquid more rapidly when made in a 1:3 ratio (37 s) than in a 1:4 ratio (45 s) but all combinations took similar times to reach 0.4 ml liquid formation. For all the experiments, there was no statistical significant difference between operators. Conclusions The Tessari method of foam production for sodium tetradecyl sulphate sclerosant is consistent and reproducible even when made by inexperienced operators. The best quality foam with micro bubbles should be used within the first minute after production.

scholarly journals Development of Bubble Characteristics on Chute Spillway Bottom

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1129
Author(s):  
Ruidi Bai ◽  
Chang Liu ◽  
Bingyang Feng ◽  
Shanjun Liu ◽  
Faxing Zhang
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Dissipation Rate ◽  
Bubble Diameter ◽  
Bubble Size Distribution ◽  
Impact Zone ◽  
Air Bubble ◽  
Air Supply ◽  
Bubble Characteristics ◽  
The Impact

Chute aerators introduce a large air discharge through air supply ducts to prevent cavitation erosion on spillways. There is not much information on the microcosmic air bubble characteristics near the chute bottom. This study was focused on examining the bottom air-water flow properties by performing a series of model tests that eliminated the upper aeration and illustrated the potential for bubble variation processes on the chute bottom. In comparison with the strong air detrainment in the impact zone, the bottom air bubble frequency decreased slightly. Observations showed that range of probability of the bubble chord length tended to decrease sharply in the impact zone and by a lesser extent in the equilibrium zone. A distinct mechanism to control the bubble size distribution, depending on bubble diameter, was proposed. For bubbles larger than about 1–2 mm, the bubble size distribution followed a—5/3 power-law scaling with diameter. Using the relationship between the local dissipation rate and bubble size, the bottom dissipation rate was found to increase along the chute bottom, and the corresponding Hinze scale showed a good agreement with the observations.

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