A comprehensive flow regime map for microchannel flow boiling with quantitative transition criteria

In relation to development of the flow regime criteria for rod bundles, this paper provides an experimental flow regime map and compares the experimental map with the existing flow regime transition criteria for vertical rod bundles so far. An experiment of vertical adiabatic air-water flow was conducted under an atmosphere pressure conditions. The experiment facility was composed of 5×5 rod arranged on a square pitch in a square shell with 9.5 mm outside diameter and 12.6 mm pitch. A total of 242 data sets were acquired consisting of superficial gas flow rates, 0.02–8.69 m/s, and superficial liquid flow rates, 0.02–2.13 m/s. A new flow regime map was obtained and the flow regime transition model for rod bundles was validated by the measured flow regime map. A fairly good agreement with some discrepancies has been obtained between the existing flow regime transition criteria and measured flow regime maps for rod bundles.

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Modified Model for Improved Flow Regime Prediction in Internally-Grooved Tubes

Volume 2: Thermal Management; Data Centers and Energy Efficient Electronic Systems ◽

10.1115/ipack2013-73199 ◽

2013 ◽

Cited By ~ 2

Author(s):

Darin J. Sharar ◽

Nicholas R. Jankowski ◽

Avram Bar-Cohen

Keyword(s):

Flow Regime ◽

Performance Improvement ◽

Annular Flow ◽

Tube Flow ◽

Two Phase ◽

Modified Model ◽

Transition Criteria ◽

Two Phase Heat Transfer ◽

Regime Map ◽

Flow Regime Map

The absence of phenomenological insights and accurate flow regime models makes it difficult to predict the improved effectiveness of internally-grooved tubes for two-phase heat transfer. A re-interpretation of available data and flow regime maps is used to suggest that performance improvement is a result of early transition to Annular flow. A modified flow regime map, with a newly-developed Stratified-Wavy to Annular transition criteria for internally-grooved tubes, is shown to increase regime prediction accuracy by 27% relative to the traditional, smooth tube flow regime prediction.

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A four-quadrant flow regime map for two-phase liquid-solids and gas-solids fluidization systems

Powder Technology ◽

10.1016/j.powtec.2021.08.050 ◽

2021 ◽

Author(s):

Zeneng Sun ◽

Jesse Zhu

Keyword(s):

Flow Regime ◽

Two Phase ◽

Phase Liquid ◽

Four Quadrant ◽

Regime Map ◽

Flow Regime Map

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A consolidated flow regime map of upward gas fluidization

AIChE Journal ◽

10.1002/aic.16672 ◽

2019 ◽

Vol 65 (9) ◽

Cited By ~ 5

Author(s):

Zeneng Sun ◽

Jesse Zhu

Keyword(s):

Flow Regime ◽

Gas Fluidization ◽

Regime Map ◽

Flow Regime Map

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Non-dimensionalization and three-dimensional flow regime map for fluidization analyses

Chemical Engineering Science ◽

10.1016/j.ces.2014.08.006 ◽

2014 ◽

Vol 119 ◽

pp. 199-211 ◽

Cited By ~ 7

Author(s):

Kenya Kuwagi ◽

Atsuto Kogane ◽

Hiroyuki Hirano ◽

Azri Bin Alias ◽

Toshihiro Takami

Keyword(s):

Flow Regime ◽

Three Dimensional ◽

Three Dimensional Flow ◽

Dimensional Flow ◽

Regime Map ◽

Flow Regime Map

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Flow Regime Map for Two Dimensional Spouted Bed and Comparison with Simulation by Discrete Element Method.

KAGAKU KOGAKU RONBUNSHU ◽

10.1252/kakoronbunshu.25.1037 ◽

1999 ◽

Vol 25 (6) ◽

pp. 1037-1039 ◽

Cited By ~ 5

Author(s):

TOSHIRO TSUJI ◽

TOMOKO CHIBA ◽

TOSHIHARU SHIBATA ◽

OSAMU UEMAKI ◽

HIRONORI ITOH

Keyword(s):

Discrete Element Method ◽

Flow Regime ◽

Discrete Element ◽

Two Dimensional ◽

Spouted Bed ◽

Regime Map ◽

Flow Regime Map ◽

Element Method

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Shear thickening regimes of dense non-Brownian suspensions

Soft Matter ◽

10.1039/c5sm02326b ◽

2016 ◽

Vol 12 (3) ◽

pp. 914-924 ◽

Cited By ~ 50

Author(s):

Christopher Ness ◽

Jin Sun

Keyword(s):

Flow Regime ◽

Shear Thickening ◽

Suspended Particles ◽

Soft Particle ◽

Regime Map ◽

Flow Regime Map

A flow regime map for suspended particles that unifies aspects of colloidal, granular and soft-particle rheology across remarkably diverse scales.

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A New Heat Transfer Correlation and Flow Regime Map for Tube Bundles

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2906469 ◽

1990 ◽

Vol 112 (1) ◽

pp. 150-156 ◽

Cited By ~ 3

Author(s):

Y. A. Hassan ◽

T. K. Blanchat

Keyword(s):

Heat Transfer ◽

Flow Regime ◽

Steam Generator ◽

Tube Bundle ◽

Nucleate Boiling ◽

Heat Transfer Correlation ◽

Transfer Coefficients ◽

Tube Bundles ◽

Regime Map ◽

Flow Regime Map

A RELAP5/MOD2 computer code model for a once-through steam generator has been developed. The calculated heat transfer in the nucleate boiling flow was underpredicted as shown by a predicted superheat of only 11°C (20°F), whereas plant values range from 22–30°C (40–60°F). Existing heat transfer correlations used in thermal-hydraulic computer codes do not provide accurate predictions of the measurement-derived secondary convective heat transfer coefficients for steam generators because they were developed for flow inside tubes, not tube bundles. The RELAP5/MOD2 flow regime map was modified to account for flow across bundles. This modified flow regime map predicts better transition criteria between bubbly-to-slug and slug-to-annular flow. Consequently, improved saturated conditions for the fluid flow at the entrance to the boiler were obtained. A modified Chen-type heat transfer correlation was developed to predict the boiling heat transfer for steam generator tube bundle geometries. This correlation predicts better superheat.

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The Intertube Falling Film: Part 1—Flow Characteristics, Mode Transitions, and Hysteresis

Journal of Heat Transfer ◽

10.1115/1.2822676 ◽

1996 ◽

Vol 118 (3) ◽

pp. 616-625 ◽

Cited By ~ 117

Author(s):

X. Hu ◽

A. M. Jacobi

Keyword(s):

Heat Transfer ◽

Flow Characteristics ◽

Horizontal Tube ◽

Falling Film ◽

Flow And Heat Transfer ◽

Transition Criteria ◽

Continuous Sheet ◽

Mode Transitions ◽

Regime Map ◽

Flow Regime Map

When a liquid film falls from one horizontal tube to another below it, the flow may take the form of discrete droplets, jets, or a continuous sheet; the mode plays an important role in the wetting and heat transfer characteristics of the film. Experiments are reported that explore viscous, surface tension, inertial, and gravitational effects on the falling-film mode transitions. New flow classifications, a novel flow regime map, and unambiguous transition criteria for each of the mode transitions are provided. This research is part of an overall study of horizontal-tube, falling-film flow and heat transfer, and the results may have important implications on the design and operation of falling-film heat exchangers.

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