Optimization of microchannel heat sinks using entropy generation minimization method

2006 ◽  
Author(s):  
W.A. Khan ◽  
M.M. Yovanovich ◽  
J.R. Culham
Keyword(s):  
Entropy Generation ◽  
Heat Sinks ◽  
Minimization Method ◽  
Entropy Generation Minimization ◽  
Microchannel Heat Sinks

Optimization of Pin-Fin Heat Sinks in Bypass Flow Using Entropy Generation Minimization Method

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
W. A. Khan ◽  
J. R. Culham ◽  
M. M. Yovanovich
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Entropy Generation ◽  
Heat Sink ◽  
Heat Sinks ◽  
Entropy Generation Rate ◽  
Bypass Flow ◽  
Minimization Method ◽  
Pin Fin ◽  
Entropy Generation Minimization

An entropy generation minimization method is applied to study the thermodynamic losses caused by heat transfer and pressure drop for the fluid in a cylindrical pin-fin heat sink and bypass flow regions. A general expression for the entropy generation rate is obtained by considering control volumes around the heat sink and bypass regions. The conservation equations for mass and energy with the entropy balance are applied in both regions. Inside the heat sink, analytical/empirical correlations are used for heat transfer coefficients and friction factors, where the reference velocity used in the Reynolds number and the pressure drop is based on the minimum free area available for the fluid flow. In bypass regions theoretical models, based on laws of conservation of mass, momentum, and energy, are used to predict flow velocity and pressure drop. Both in-line and staggered arrangements are studied and their relative performance is compared to the same thermal and hydraulic conditions. A parametric study is also performed to show the effects of bypass on the overall performance of heat sinks.

Optimization of Pin-Fin Heat Sinks in Bypass Flow Using Entropy Generation Minimization Method

2007 ◽  
Author(s):  
Waqar A. Khan ◽  
Michael M. Yovanovich
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Entropy Generation ◽  
Heat Sink ◽  
Heat Sinks ◽  
Entropy Generation Rate ◽  
Bypass Flow ◽  
Minimization Method ◽  
Pin Fin ◽  
Entropy Generation Minimization

An entropy generation minimization, EGM, method is applied to study the thermodynamic losses caused by heat transfer and pressure drop for the fluid in a cylindrical pin-fin heat sink and bypass flow regions. A general expression for the entropy generation rate is obtained by considering control volumes around heat sink and bypass regions. The conservation equations for mass and energy with the entropy balance are applied in both regions. Inside the heat sink, analytical/empirical correlations are used for heat transfer coefficients and friction factors, where the reference velocity used in Reynolds number and pressure drop is based on the minimum free area available for the fluid flow. In bypass regions theoretical models, based on laws of conservation of mass, momentum and energy, are used to predict flow velocity and pressure drop. Both in-line and staggered arrangements are studied and their relative performance is compared for the same thermal and hydraulic conditions. A parametric study is also performed to show the effects of bypass on the overall performance of heat sinks.

Entropy Analysis of a R32/CO2 Cascade Refrigeration Cycle

2014 ◽  
Vol 672-674 ◽  
pp. 1676-1679
Author(s):  
Jian Xiao ◽  
Ying Fu Liu
Keyword(s):  
Entropy Generation ◽  
Temperature Difference ◽  
Design Parameters ◽  
Refrigeration Cycle ◽  
Total Entropy ◽  
Entropy Analysis ◽  
Minimization Method ◽  
Entropy Generation Minimization ◽  
Cascade Refrigeration

In order to study the performance of a R32/CO2 cascade refrigeration cycle, entropy generation minimization method was adopted to get the influence of some important operating and design parameters on the performance of the system and entropy generations of each component and the whole system, such as the evaporating temperature(Te), the condensing temperature(Tk) and the temperature difference in the cascade condenser(ΔT). The results indicate that there are a maximum COP and a minimum total entropy generation of the system at the optimal condensing temperature of the cascade condenser when Te, Tk and ΔT are constant. The total entropy generations of the throttling device, the condenser and the compressor of HTC, the cascade condenser and the compressor of LTC are above 80% of the total entropy generation of the whole system.

Application of the entropy generation minimization method to solid mechanics

2009 ◽  
Vol 97 (4) ◽  
pp. 777-789 ◽  
Author(s):  
Mehdi Baneshi ◽  
Khosrow Jafarpur ◽  
Mojtaba Mahzoon
Keyword(s):  
Entropy Generation ◽  
Solid Mechanics ◽  
Minimization Method ◽  
Entropy Generation Minimization

scholarly journals Numerical Analysis of Flow Field and Heat Transfer of 2D Wavy Ducts and Optimization by Entropy Generation Minimization Method

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Ouldouz Nourani Zonouz ◽  
Mehdi Salmanpour
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Entropy Generation ◽  
Wave Number ◽  
Working Fluid ◽  
Finite Volume Scheme ◽  
Computational Domain ◽  
Minimization Method ◽  
Entropy Generation Minimization ◽  
Temperature Boundary

This article provided a research for the trend of heat transfer and flow field through a 2-dimensional wavy duct. To construct a grid mesh, the physical domain was transferred to the computational domain and finite volume scheme was used for discretizing the governing equations. Through the simulation, the flow regime stayed in laminar mode. Constant temperature boundary condition has been used for solid walls. Air was used as a working fluid. Existence of waves makes some phenomenon like flow separation. Effect of Reynolds number, wave width, and wave number has been analyzed and velocity distribution, heat transfer coefficient, and tangential stress were computed for different cases. The final results were compared with the same straight duct. The entropy generation minimization method has been used for better comparison between final results.

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