Condensation in Rotating Stepped Wall Heat Pipes with Hysteretic Annular Flow

1998 ◽  
Vol 12 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Lanchao Lin ◽  
Amir Faghri
Keyword(s):  
Annular Flow ◽  
Heat Pipes

Core annular flow theory as applied to the adiabatic section of heat pipes

2020 ◽  
Vol 32 (8) ◽  
pp. 083607
Author(s):  
Aishwarya Rath ◽  
M. R. Flynn
Keyword(s):  
Annular Flow ◽  
Heat Pipes ◽  
Flow Theory ◽  
Adiabatic Section

Correlations of Critical Froude Number for Annular-Rimming Flow in Rotating Heat Pipes

2001 ◽  
Vol 123 (4) ◽  
pp. 909-913 ◽  
Author(s):  
J. Baker ◽  
T. Oliver ◽  
L. Lin ◽  
R. Ponnapan ◽  
J. Leland
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Annular Flow ◽  
Heat Pipes ◽  
Operating Conditions ◽  
Uniform Thickness ◽  
Heat Transfer Characteristics ◽  
Rimming Flow ◽  
Critical Rotational Speed ◽  
Flow Transitions

The behavior of flow within a rotating finite length cylinder has been investigated. For low rotational speeds, the flow is characterized by a non-uniform thickness i.e., rimming flow. Above a critical rotational speed, the flow transitions to annular flow. Correlations developed from the experimental data are presented for the three regimes: onset of annular flow, complete annular flow, and collapse of annular flow. The correlation for the collapse of annular flow compared well with a previously presented, theoretically developed correlation. Given that the heat transfer characteristics of rotating heat pipes depend upon the film thickness of the fluid charge, the correlations presented here will be valuable in determining regular operating conditions.

scholarly journals Thermodynamic Analysis of the Dryout Limit of Oscillating Heat Pipes

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6346
Author(s):  
Florian Schwarz ◽  
Vladimir Danov ◽  
Alexander Lodermeyer ◽  
Alexander Hensler ◽  
Stefan Becker
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Analytical Data ◽  
Heat Pipes ◽  
Threshold Value ◽  
Vapor Quality ◽  
Cooling Systems ◽  
Key Factor ◽  
Operating Limits ◽  
Experimental Approaches

The operating limits of oscillating heat pipes (OHP) are crucial for the optimal design of cooling systems. In particular, the dryout limit is a key factor in optimizing the functionality of an OHP. As shown in previous studies, experimental approaches to determine the dryout limit lead to contradictory results. This work proposes a compact theory to predict a dryout threshold that unifies the experimental and analytical data. The theory is based on the influence of vapor quality on the flow pattern. When the vapor quality exceeds a certain limit (x = 0.006), the flow pattern changes from slug flow to annular flow and the heat transfer decreases abruptly. The results indicate a uniform threshold value, which has been validated experimentally and by the literature. With that approach, it becomes possible to design an OHP with an optimized filling ratio and, hence, substantially improve its cooling abilities.

Effect of particle size on erosion measurements and predictions in annular flow for an elbow

Wear ◽  
2020 ◽  
pp. 203579
Author(s):  
G. Haider ◽  
M. Othayq ◽  
J. Zhang ◽  
R.E. Vieira ◽  
S.A. Shirazi
Keyword(s):  
Particle Size ◽  
Annular Flow ◽  
Effect Of Particle Size
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