Numerical investigation of natural convection heat transfer from vertical cylinder with annular fins

2017 ◽  
Vol 111 ◽  
pp. 146-159 ◽  
Author(s):  
Jnana Ranjan Senapati ◽  
Sukanta Kumar Dash ◽  
Subhransu Roy
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Investigation ◽  
Convection Heat Transfer ◽  
Vertical Cylinder ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Annular Fins

Comparison of Natural Convection Heat Transfer from a Vertical Cylinder Fitted with Annular Step Fins and Annular Triangular Fins

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Shubham Verma ◽  
Harishchandra Thakur
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Vertical Cylinder ◽  
Navier Stokes ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Navier Stokes Equation ◽  
Heat Transfers ◽  
Annular Fins

Natural convection heat transfer from a vertical cylinder with annular step and triangular fins has been studied numerically at various Rayleigh numbers within the laminar range. The computations were carried at constant fin spacing to tube diameter ratio of 1. In the current study, numerical simulations of Navier-Stokes equation supported with the energy equation are conducted for a vertical cylinder with annular step fins as well as triangular annular fins using the algebraic multi-grid solver of Fluent 15. With an increase in Rayleigh number, we’ve discovered a trend that the surface Nusselt number goes on increasing with comparison from a simple rectangular fin. Apart from this, the material needed for the step and triangular fins has been reduced with enhancements in the heat transfers.

Experimental and Numerical Investigation on Natural Convection Heat Transfer of TiO2–Water Nanofluids in a Square Enclosure

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Yanwei Hu ◽  
Yurong He ◽  
Shufu Wang ◽  
Qizhi Wang ◽  
H. Inaki Schlaberg
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Natural Convection ◽  
Numerical Investigation ◽  
Convection Heat Transfer ◽  
Distribution Functions ◽  
Lattice Boltzmann Model ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Square Enclosure

An experimental and numerical investigation on natural convection heat transfer of TiO2–water nanofluids in a square enclosure was carried out for the present work. TiO2–water nanofluids with different nanoparticle mass fractions were prepared for the experiment and physical properties of the nanofluids including thermal conductivity and viscosity were measured. Results show that both thermal conductivity and viscosity increase when increasing the mass fraction of TiO2 nanoparticles. In addition, the thermal conductivity of nanofluids increases, while the viscosity of nanofluids decreases with increasing the temperature. Nusselt numbers under different Rayleigh numbers were obtained from experimental data. Experimental results show that natural convection heat transfer of nanofluids is no better than water and even worse when the Rayleigh number is low. Numerical studies are carried out by a Lattice Boltzmann model (LBM) coupling the density and the temperature distribution functions to simulate the convection heat transfer in the enclosure. The experimental and numerical results are compared with each other finding a good match in this investigation, and the results indicate that natural convection heat transfer of TiO2–water nanofluids is more sensitive to viscosity than to thermal conductivity.

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