Flow and radiation heat transfer of a nanofluid over a stretching sheet with velocity slip and temperature jump in porous medium

2013 ◽  
Vol 350 (5) ◽  
pp. 990-1007 ◽  
Author(s):  
Liancun Zheng ◽  
Chaoli Zhang ◽  
Xinxin Zhang ◽  
Junhong Zhang
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Stretching Sheet ◽  
Temperature Jump ◽  
Radiation Heat Transfer ◽  
Velocity Slip ◽  
Radiation Heat

scholarly journals Evaluation of radiation heat transfer in porous medial: Application for a pebble bed modular reactor cooled by CO2 gas

2013 ◽  
Vol 28 (2) ◽  
pp. 118-127
Author(s):  
Kamel Sidi-Ali ◽  
Khaled Oukil ◽  
Tinhinane Hassani ◽  
Yasmina Amri ◽  
Abdelmoumane Alem
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Free Convection ◽  
Radiation Heat Transfer ◽  
Convection Heat Transfer ◽  
Emergency Situation ◽  
System Of Equations ◽  
Radiation Heat ◽  
Pebble Bed ◽  
Free Convection Heat

This work analyses the contribution of radiation heat transfer in the cooling of a pebble bed modular reactor. The mathematical model, developed for a porous medium, is based on a set of equations applied to an annular geometry. Previous major works dealing with the subject have considered the forced convection mode and often did not take into account the radiation heat transfer. In this work, only free convection and radiation heat transfer are considered. This can occur during the removal of residual heat after shutdown or during an emergency situation. In order to derive the governing equations of radiation heat transfer, a steady-state in an isotropic and emissive porous medium (CO2) is considered. The obtained system of equations is written in a dimensionless form and then solved. In order to evaluate the effect of radiation heat transfer on the total heat removed, an analytical method for solving the system of equations is used. The results allow quantifying both radiation and free convection heat transfer. For the studied situation, they show that, in a pebble bed modular reactor, more than 70% of heat is removed by radiation heat transfer when CO2 is used as the coolant gas.

scholarly journals Bioconvection heat transfer of a nanofluid over a stretching sheet with velocity slip and temperature jump

2017 ◽  
Vol 21 (6 Part A) ◽  
pp. 2347-2356 ◽  
Author(s):  
Bingyu Shen ◽  
Liancun Zheng ◽  
Chaoli Zhang ◽  
Xinxin Zhang
Keyword(s):  
Heat Transfer ◽  
Stretching Sheet ◽  
Temperature Jump ◽  
Lewis Number ◽  
Velocity Slip ◽  
Analysis Method ◽  
Gyrotactic Microorganisms ◽  
Similarity Transformations ◽  
Homotopy Analysis ◽  
Effects Of Radiation

This paper presents an investigation for bioconvection heat transfer of a nanofluid containing gyrotactic microorganisms over a stretching sheet, in which the effects of radiation, velocity slip, and temperature jump are taken into account. The non-linear governing equations are reduced into four ordinary differential equations by similarity transformations and solved by homotopy analysis method, which is verified with numerical results in good agree. Results indicate that the density of motile microorganisms and gyrotactic microorganisms increase with bioconvection Rayleigh number, while decrease with increasing in bioconvection Peclet number and bioconvection Lewis number. It is also found that the Nusselt number, Sherwood number, and gyrotactic microorganisms density depend strongly on the buoyancy, nanofluids, and bioconvection parameters.

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