scholarly journals Numerical Simulation of Convective-Radiative Heat Transfer

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5399
Author(s):  
Mikhail A. Sheremet
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Conduction ◽  
Heat Exchangers ◽  
Transport Process ◽  
Radiative Heat ◽  
Nuclear Reactors ◽  
Atmospheric Boundary Layers ◽  
Natural Systems ◽  
Biomedical Systems

Heat transfer including heat conduction, thermal convection, and thermal radiation is a major transport process that occurs in various engineering and natural systems such as heat exchangers, solar collectors, nuclear reactors, atmospheric boundary layers, electronical and biomedical systems, and others. [...]

Numerical Simulation and Optimization of Radial Heat Pipe Heat Exchanger Based on Field Synergy Principle

2013 ◽  
Vol 834-836 ◽  
pp. 1418-1422
Author(s):  
Qing Yun Liu ◽  
Fu Bing Tu ◽  
Sheng Yang Gao
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Transfer Coefficient ◽  
Heat Exchangers ◽  
Synergy Effect ◽  
Field Synergy ◽  
Field Synergy Principle ◽  
Radial Heat ◽  
The Heat Transfer Coefficient ◽  
Pipe Heat

This paper mainly explores the numerical simulation of flow and temperature fields in the shell-side of the radial heat pipe heat exchangers (HPHE), using CFD software-FLUENT. Field synergy principle is applied to analyze heat and mass transfer mechanism of heat exchangers; also, the influence of the variation of principle constructor parameters of heat exchangers on the field synergy effect and heat exchange performance has been studied. It has been found that better performance of heat exchangers is achieved with better field synergy effect; in the context of increasing transverse and longitudinal tube pitches within certain values of data, the heat transfer coefficient decreases as synergy angle increases. Variation of fin height has little effect on synergy angle, but it would decrease the heat transfer coefficient at unit pressure drop (k/Δp) as it increases; as fin pitch increases, the synergy angle first decreases and then grows, while k/Δp first increases and then decreases. The optimal ranges of heat exchanger structure parameters values were found.

The Effectiveness-NTU Relationship of Microchannel Counter Flow Heat Exchangers With Axial Heat Conduction

2007 ◽  
Author(s):  
B. Mathew ◽  
H. Hegab
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Microchannel Heat Exchanger ◽  
Axial Temperature ◽  
Axial Heat ◽  
Relationship Of ◽  
End Wall ◽  
Axial Heat Conduction

In this paper the effect of axial heat conduction on the thermal performance of a microchannel heat exchanger with non-adiabatic end walls is studied. The two ends of the wall separating the coolant are assumed to be subjected to boundary condition of the first kind. As the end walls are not insulated heat transfer between the microchannel heat exchanger and its surroundings occur. Analytical equations have been formulated for predicting the axial temperature of the coolants and the wall as well as for determining the effectiveness of both fluids. The effectiveness of the fluids has been found to depend on the NTU, axial heat conduction parameter and end wall temperatures. The heat transfer through the end walls have been expressed in nondimensional terms. The nondimensional heat transfer from both ends of the wall also depends on the axial heat conduction parameter and temperature gradient at the end walls. A new parameter, performance factor, has been proposed for comparing the variation in effectiveness due to axial heat conduction coupled with heat transfer with the effectiveness without axial heat conduction. The effectiveness of both the hot and cold fluid for several cases of end wall temperatures and axial heat conduction parameter are analyzed in this paper for better understanding of heat transfer dynamics of microchannel heat exchangers.

scholarly journals Validation of accuracy and stability of numerical simulation for 2-D heat transfer system by an entropy production approach

2017 ◽  
Vol 21 (suppl. 1) ◽  
pp. 97-104
Author(s):  
Ali Brohi ◽  
Haochun Zhang ◽  
Kossi Min-Dianey ◽  
Muhammad Rafique ◽  
Muhammad Hassan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Conduction ◽  
Entropy Production ◽  
Heat Conduction Problem ◽  
Current Approach ◽  
Transfer System ◽  
Heat Transfer System ◽  
The Stability ◽  
Accuracy And Stability

The entropy production in 2-D heat transfer system has been analyzed systematically by using the finite volume method, to develop new criteria for the numerical simulation in case of multidimensional systems, with the aid of the CFD codes. The steady-state heat conduction problem has been investigated for entropy production, and the entropy production profile has been calculated based upon the current approach. From results for 2-D heat conduction, it can be found that the stability of entropy production profile exhibits a better agreement with the exact solution accordingly, and the current approach is effective for measuring the accuracy and stability of numerical simulations for heat transfer problems.

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