scholarly journals Force Balance Model Assessment for Mechanistic Prediction of Sliding Bubble Velocity in Vertical Subcooled Boiling Flow

2020 ◽  
Author(s):  
Junsoo Yoo ◽  
◽  
Yassin Hassan
Keyword(s):  
Force Balance ◽  
Bubble Velocity ◽  
Balance Model ◽  
Model Assessment ◽  
Subcooled Boiling ◽  
Boiling Flow

Investigation of the Influence of Elevated Pressure on Subcooled Boiling Flow—Model Evaluation Toward Generic Approach

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Sara Vahaji ◽  
Sherman Chi Pok Cheung ◽  
Guan Heng Yeoh ◽  
Jiyuan Tu
Keyword(s):  
Mechanistic Model ◽  
Elevated Pressure ◽  
Nucleation Site ◽  
Empirical Models ◽  
Mechanistic Modeling ◽  
Force Balance ◽  
Balance Model ◽  
Subcooled Boiling ◽  
Flow Conditions ◽  
Wide Range

Modeling subcooled boiling flows in vertical channels has relied heavily on the utilization of empirical correlations for the active nucleation site density, bubble departure diameter, and bubble departure frequency. Following the development and application of mechanistic modeling at low pressures, the capability of the model to resolve flow conditions at elevated pressure up to 10 bar is thoroughly assessed and compared with selected empirical models. Predictions of the mechanistic and selected empirical models are validated against two experimental data at low to elevated pressures. The results demonstrate that the mechanistic model is capable of predicting the heat and mass transfer processes. In spite of some drawbacks of the currently adopted force balance model, the results still point to the great potential of the mechanistic model to predict a wide range of flow conditions in subcooled boiling flows.

scholarly journals Velocity bias in intrusive gas-liquid flow measurements

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
B. Hohermuth ◽  
M. Kramer ◽  
S. Felder ◽  
D. Valero
Keyword(s):  
Liquid Flow ◽  
Breaking Waves ◽  
Correction Method ◽  
Force Balance ◽  
Bubble Velocity ◽  
Natural Environments ◽  
Flow Measurements ◽  
Gas Liquid Flow ◽  
Liquid Flows ◽  
Velocity Bias

AbstractGas–liquid flows occur in many natural environments such as breaking waves, river rapids and human-made systems, including nuclear reactors and water treatment or conveyance infrastructure. Such two-phase flows are commonly investigated using phase-detection intrusive probes, yielding velocities that are considered to be directly representative of bubble velocities. Using different state-of-the-art instruments and analysis algorithms, we show that bubble–probe interactions lead to an underestimation of the real bubble velocity due to surface tension. To overcome this velocity bias, a correction method is formulated based on a force balance on the bubble. The proposed methodology allows to assess the bubble–probe interaction bias for various types of gas-liquid flows and to recover the undisturbed real bubble velocity. We show that the velocity bias is strong in laboratory scale investigations and therefore may affect the extrapolation of results to full scale. The correction method increases the accuracy of bubble velocity estimations, thereby enabling a deeper understanding of fundamental gas-liquid flow processes.

scholarly journals A force balance model for the motion, impact, and bounce of bubbles

2014 ◽  
Vol 26 (9) ◽  
pp. 092101 ◽  
Author(s):  
Evert Klaseboer ◽  
Rogerio Manica ◽  
Maurice H. W. Hendrix ◽  
Claus-Dieter Ohl ◽  
Derek Y. C. Chan
Keyword(s):  
Force Balance ◽  
Balance Model
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