A Nondimensional Analysis of Boiling Dry a Vertical Channel with a Uniform Heat Flux

1981 ◽  
Vol 103 (4) ◽  
pp. 667-672 ◽  
Author(s):  
K. H. Sun ◽  
R. B. Duffey ◽  
C. Lin
Keyword(s):  
Heat Flux ◽  
Nuclear Power ◽  
Closed Form Solution ◽  
Vertical Channel ◽  
Form Solution ◽  
Uniform Heat Flux ◽  
Two Phase ◽  
Drift Flux ◽  
Rod Bundle ◽  
Uniform Heat

A thermal-hydraulic model has been developed for describing the phenomenon of hydrodynamically-controlled dryout, or the boil-off phenomenon, in a vertical channel with a spatially-averaged or uniform heat flux. The use of the drift flux correlation for the void fraction profile, along with mass and energy balances for the system, leads to a dimensionless closed-form solution for the predictions of two-phase mixture levels and collapsed liquid levels. The physical significance of the governing dimensionless parameters are discussed. Comparisons with data from single-tube experiments, a 3 × 3 rod bundle experiment, and the Three Mile Island nuclear power plant show good agreement.

scholarly journals Two-phase flow pattern and heat transfer coefficients of R245fa/R134a under non-uniform heat flux

2019 ◽  
Vol 65 (17) ◽  
pp. 1741-1751
Author(s):  
Yani Lu ◽  
Li Zhao ◽  
Shuai Deng ◽  
Dongpeng Zhao ◽  
Xianhua Nie ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Uniform Heat Flux ◽  
Phase Flow ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Heat Transfer Coefficients ◽  
Uniform Heat

Local Thermal Non-Equilibrium in Mixed Convection in Channels Partially Heated at Uniform Heat Flux Filled With a Porous Medium

2014 ◽  
Author(s):  
Bernardo Buonomo ◽  
Oronzio Manca ◽  
Paolo Mesolella ◽  
Sergio Nardini
Keyword(s):  
Heat Flux ◽  
Mixed Convection ◽  
Metal Foam ◽  
Vertical Channel ◽  
Boussinesq Approximation ◽  
Uniform Heat Flux ◽  
Aspect Ratios ◽  
Uniform Heat ◽  
Lower Temperature ◽  
Non Equilibrium

A numerical analysis of mixed convection in a vertical channel filled with metal foam partially heated at uniform heat flux is studied numerically. Local thermal non-equilibrium and Brinkman-Forchheimer-extended Darcy model are assumed. Boussinesq approximation with constant thermophysical proprieties are considered. Results are carried out for an aluminium foam with 10 pore per inch (PPI) and ε=0.909, the fluid is air. Results, for different Reynolds numbers and geometrical aspect ratios, are given in terms of solid and fluid temperatures, at heated walls and inside the channel at several heights, velocity profile along the channel, local and average Nusselt numbers. Results show that diffusive effect resulted lower temperature values inside the solid and the fluid temperatures are higher in all considered cases. For heated channel with smaller aspect ratios, an average Nusselt number increase is found for solid and fluid phases.

Investigation on the temperature distribution in the two-phase spider netted microchannel network heat sink with non-uniform heat flux

2021 ◽  
Vol 169 ◽  
pp. 107079
Author(s):  
Hui Tan ◽  
Pingan Du ◽  
Kuan Zong ◽  
Guangyao Meng ◽  
Xin Gao ◽  
...  
Keyword(s):  
Heat Flux ◽  
Temperature Distribution ◽  
Heat Sink ◽  
Uniform Heat Flux ◽  
Two Phase ◽  
Uniform Heat

Two-phase investigation of water-Al2O3 nanofluid in a micro concentric annulus under non-uniform heat flux boundary conditions

2019 ◽  
Vol 30 (4) ◽  
pp. 1795-1814 ◽  
Author(s):  
Davood Toghraie ◽  
Ramin Mashayekhi ◽  
Hossein Arasteh ◽  
Salman Sheykhi ◽  
Mohammadreza Niknejadi ◽  
...  
Keyword(s):  
Heat Flux ◽  
Reynolds Number ◽  
Boundary Conditions ◽  
Surface Area ◽  
Uniform Heat Flux ◽  
Two Phase ◽  
Content Type ◽  
Concentric Annulus ◽  
Uniform Heat ◽  
Flux Boundary Conditions

Purpose This is a 3D numerical study of convective heat transfer through a micro concentric annulus governing non-uniform heat flux boundary conditions employing water-Al2O3 nanofluid. The nanofluid is modeled using two-phase mixture model, as it has a good agreement to experimental results. Design/methodology/approach Half of the inner pipe surface area of the annulus section of a double pipe heat exchanger is exposed to a constant heat flux which two models are considered to divide the exposing surface area to smaller ones considering the fact that in all cases half of the inner pipe surface area has to be exposed to the heat flux: in model (A), the exposing surface area is divided radially to two parts (A1), four parts (A2) and eight parts (A3) by covering the whole length of the annulus and in model (B) the exposing surface area is divided axially to two parts (B1), four parts (B2) and eight parts (B3) by covering half of the annulus radially. Findings The results reveal that model (B) leads to higher Nusselt numbers compared to model (A); however, at Reynolds number 10, model (A3) exceeds model (B3). The average Nusselt number is increased up to 142 and 83 per cent at models (A3) with Reynolds number 10 and model (B3) with Reynolds number 1000, respectively. Originality/value This paper is a two-phase investigation of water-Al2O3 nanofluid in a micro concentric annulus under non-uniform heat flux boundary conditions.

High pressure rod bundle DNB data with axially non-uniform heat flux

1974 ◽  
Vol 31 (1) ◽  
pp. 1-20 ◽  
Author(s):  
E.R. Rosal ◽  
J.O. Cermak ◽  
L.S. Tong ◽  
J.E. Casterline ◽  
S. Kokolis ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Pressure ◽  
Uniform Heat Flux ◽  
Rod Bundle ◽  
Uniform Heat

Effect of a moving plate on heat transfer in a uniform heat flux vertical channel

2008 ◽  
Vol 51 (15-16) ◽  
pp. 3906-3912 ◽  
Author(s):  
Assunta Andreozzi ◽  
Nicola Bianco ◽  
Oronzio Manca ◽  
Vincenzo Naso
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Vertical Channel ◽  
Uniform Heat Flux ◽  
Moving Plate ◽  
Uniform Heat

Prediction of turbulent forced convection of a nanofluid in a tube with uniform heat flux using a two phase approach

2007 ◽  
Vol 28 (2) ◽  
pp. 211-219 ◽  
Author(s):  
A. Behzadmehr ◽  
M. Saffar-Avval ◽  
N. Galanis
Keyword(s):  
Heat Flux ◽  
Forced Convection ◽  
Uniform Heat Flux ◽  
Two Phase ◽  
Phase Approach ◽  
Uniform Heat
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