Experimental and numerical study of gas to liquid ratio in stratified gas-saturated liquid blowouts’ plumes

Objectives To determine the quality of sclerosant foam produced with an automated preparation system with multiple combinations of sclerosing agents, gases, and device settings. Methods Single-use mixing capsules filled with air or O2/CO2 and polidocanol (0.25, 1, or 3%) or sodium tetradecyl sulfate (0.2 or 1%) were coupled to a customized magnetic stirrer. Stirring speed and time were adjusted between 1500 and 4000 r/min and 30 and 60 s, respectively, and characteristics of the foam produced were measured: half-life, bubble diameter, and gas-to-liquid ratio. Results With optimized device settings, the following foam characteristics were obtained: half-life range, 1.4 ± 0.9 to 5.2 ± 0.6 min; bubble diameter, 84 ± 14 to 119 ± 6 µm; and gas-to-liquid ratio, 5:1–7:1. Sodium tetradecyl sulfate foam was quicker to form than polidocanol but faster to degrade. Foams with low sclerosant concentrations and O2/CO2 required higher speed and longer time. Conclusions Suitable foam characteristics could be obtained with all combinations of sclerosing agent, concentration, and gas.

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A two-dimensional numerical study of film boiling over an elliptical cylinder in the mixed regime under aiding and orthogonal saturated liquid flow configurations

Journal of Fluid Mechanics ◽

10.1017/jfm.2020.904 ◽

2020 ◽

Vol 908 ◽

Author(s):

Nikhil Kumar Singh ◽

B. Premachandran

Keyword(s):

Liquid Flow ◽

Numerical Study ◽

Elliptical Cylinder ◽

Film Boiling ◽

Two Dimensional ◽

Saturated Liquid ◽

Mixed Regime ◽

Flow Configurations

Abstract

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Numerical study of the effect of gas-to-liquid ratio on the internal and external flows of effervescent atomizers

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2017-0125 ◽

2018 ◽

Vol 42 (4) ◽

pp. 444-456 ◽

Cited By ~ 1

Author(s):

Milad Mousavi ◽

Ali Dolatabadi

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Internal Flow ◽

Operating Conditions ◽

Liquid Ratio ◽

Spray Cone ◽

Numerical Predictions ◽

Gas To Liquid ◽

Discharge Orifice

In an effort to capture the complex evolving interface of internal and external flow in an effervescent atomizer, a compressible Eulerian method, along with the volume-of-fluid method coupled with the large eddy simulation model, are employed in a two-phase flow system. Water is injected into the atomizer with a constant mass flow rate of 0.0133 kg/s (i.e., 800 mL/min). The mass flow rate of air is adjusted to vary the gas-to-liquid ratio (GLR) from 0.55% to 2.6%. It is observed that the increase in the GLR is accompanied by an evolution of the internal flow from a complex bubbly flow to an annular flow, which consequently reduces the liquid film thickness at the discharge orifice. Further studies on the internal pressure illustrate the critical condition, which leads to choked flow and pressure oscillations at the discharge orifice. Increasing the GLR was found to affect the internal flow, resulting in changes to primary atomization parameters such as a shortening of the breakup length and a widening of the spray cone angle. The numerical predictions are in good agreement with the experimental results under the same operating conditions.

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