Gas entrainment in the mock-up of the upper plenum of a sodium cooled reactor

The slug flow regime may be appeared in subsea gas-liquid pipeline of the offshore petroleum industry. The gas entrainment process and the gas bubble distribution in liquid slug are crucial for the model of slug flow. An experimental facility was constructed and the gas bubble distributions in the liquid slug were measured by the dual-tip conductivity probe. It is found that the entrained gas is broken up into small bubbles by the high turbulent shear stress in the turbulent shear layer in the mixing zone. The small bubbles are dispersed completely and the profiles of void fraction and bubble frequency have peaks in this layer. The mechanism of gas entrainment is also presented.

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NO Emission of a Non-premixed Oxygen-Enhanced Flame in Burned Gas Entrainment above the Self-Ignition Temperature (BEST) Conditions

Combustion Science and Technology ◽

10.1080/00102202.2017.1401614 ◽

2017 ◽

Vol 190 (3) ◽

pp. 490-515

Author(s):

Jeongseog Oh ◽

Eungyeong Lee ◽

Dongsoon Noh

Keyword(s):

Ignition Temperature ◽

The Self ◽

No Emission ◽

Gas Entrainment

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A Hybrid Model for Predicting Gas Entrainment in a Small Branch From a Co-Current Flowing Gas-Liquid Regime

ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting: Volume 1, Symposia – Parts A, B, and C ◽

10.1115/fedsm-icnmm2010-31174 ◽

2010 ◽

Author(s):

Robert Bowden ◽

Wael Saleh ◽

Ibrahim Hassan

Keyword(s):

Digital Imaging ◽

Three Dimensional ◽

Flow Distribution ◽

Critical Conditions ◽

Inertial Effects ◽

Cross Sectional ◽

Gas Entrainment ◽

Small Branch ◽

Dip Angle ◽

Good Agreement

An analytical model was developed to predict the critical conditions at the onset of gas entrainment in a single downward oriented branch. The branch was installed on a horizontal square cross-sectional channel having a smooth stratified co-currently flowing gas-liquid regime in the upstream inlet region. The branch flow was simulated as a three-dimensional point-sink while the downstream run flow was treated with a uniform velocity at the critical dip location. A boundary condition was imposed in the model whereby the flow distribution between the branch and run was obtained experimentally and digital imaging was used to quantify the critical dip location through the dip angle. Three constant dip angles were evaluated in the model and results showed the dip height to have good agreement with experiments between angles of 50 and 60 degrees. The predicted upstream height, however, did not match well with the experimentally determined height due to the omission of shear and inertial effects between the upstream location and critical dip.

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