Second law optimization of convective heat transfer through a duct with constant heat flux

1989 ◽  
Vol 13 (5) ◽  
pp. 537-543 ◽  
Author(s):  
P. K. Nag ◽  
Naresh Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Constant Heat Flux ◽  
Second Law ◽  
Constant Heat

Mechanism of Convective Heat Transfer of Airflow in Deep Airway

2011 ◽  
Vol 243-249 ◽  
pp. 4998-5002
Author(s):  
Yi Jiang Wang ◽  
Guo Qing Zhou ◽  
Lei Wu ◽  
Yong Lu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Distribution ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Constant Heat Flux ◽  
Constant Heat ◽  
Mining Depth ◽  
Axial Temperature ◽  
Criterion Equation

With the increase of mining depth, an investigation of the convective heat transfer of airflow in deep airway is urgently required. The velocity and temperature distribution were derived by using the turbulence model for smooth tube. In order to simplify calculation and avoid the complicated calculation of integration, with the help of velocity-temperature distribution analogy, the criterion equation of convective heat transfer was obtained by using the model of constant heat flux. The coefficient of convective heat transfer between airflow and airway was calculated, and criterion correlation of convective heat transfer was regressed according to test data. Test results show that the axial temperature distribution of airflow is linear, which is encouraging agreement with theoretical calculating results. Hence model of constant heat flux is a viable method for studying the convective heat transfer of airflow in deep airway.

Numerical investigation of CuO-water nanofluid turbulent convective heat transfer in square cross-section duct under constant heat flux

2016 ◽  
Vol 33 (6) ◽  
pp. 1714-1728 ◽  
Author(s):  
Hsien-Hung Ting ◽  
Shuhn-Shyurng Hou
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Cross Section ◽  
Convective Heat ◽  
Constant Heat Flux ◽  
Constant Heat ◽  
Content Type

Purpose – The purpose of this paper is to numerically investigate the convective heat transfer of water-based CuO nanofluids flowing through a square cross-section duct under constant heat flux in the turbulent flow regime. Design/methodology/approach – The numerical simulation is carried out at various Peclet numbers and particle concentrations (0.1, 0.2, 0.5, and 0.8 vol%). The finite volume formulation is used with the semi-implicit method for pressure-linked equations algorithm to solve the discretized equations derived from the partial nonlinear differential equations of the mathematical model. Findings – The heat transfer coefficients and Nusselt numbers of CuO-water nanofluids increase with increases in the Peclet number as well as particle volume concentration. Also, enhancement of the heat transfer coefficient is much greater than that of the effective thermal conductivity at the same nanoparticle concentration. Research limitations/implications – Simulation of nanofluids turbulent forced convection at very high Reynolds number is worth for further study. Practical implications – The heat transfer rates through non-circular ducts are smaller than the circular tubes. Nevertheless, the pressure drop of the non-circular duct is less than that of the circular tube. This study clearly presents that the nanoparticles suspended in water enhance the convective heat transfer coefficient, despite low volume fraction between 0.1 and 0.8 percent. Adding nanoparticles to conventional fluids may enhance heat transfer performance through the non-circular ducts, leading to extensive practical applications in industries for the non-circular ducts. Originality/value – Few papers have numerically studied convective heat transfer properties of nanofluids through non-circular ducts. The present numerical results show a good agreement with the published experimental data.

Laminar convective heat transfer of nanofluids in a circular tube under constant heat flux

2009 ◽  
Vol 2 (1/2/3/4/5/6) ◽  
pp. 314 ◽  
Author(s):  
L. Syam Sundar ◽  
K.V. Sharma ◽  
Shabana Parveen ◽  
Md. Abdul Gaffar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Circular Tube ◽  
Constant Heat Flux ◽  
Constant Heat
Sign in / Sign up

Export Citation Format

Share Document