Numerical Study of Mixed Convection Flows in a U-shaped Channel: Application to the Canadian Well

2017 ◽  
Author(s):  
Meryem Naoum ◽  
Mustapha El Alami
Keyword(s):  
Mixed Convection ◽  
Numerical Study

Numerical study of double diffusive mixed convection around a heated cylinder in an enclosure

2014 ◽  
Vol 78 ◽  
pp. 169-181 ◽  
Author(s):  
Hongtao Xu ◽  
Ruixue Xiao ◽  
Fariborz Karimi ◽  
Mo Yang ◽  
Yuwen Zhang
Keyword(s):  
Mixed Convection ◽  
Numerical Study ◽  
Heated Cylinder ◽  
Double Diffusive

scholarly journals Numerical Simulation of Multiplicity and Stability of Mixed Convection in Rotating Curved Ducts

2005 ◽  
Vol 2005 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Liqiu Wang ◽  
Tianliang Yang
Keyword(s):  
Mixed Convection ◽  
Buoyancy Force ◽  
Numerical Study ◽  
Chaotic Oscillation ◽  
Periodic Oscillation ◽  
Dynamic Responses ◽  
Subharmonic Bifurcation ◽  
Temporal Oscillation ◽  
The Rich ◽  
Curved Ducts

A numerical study is made on the fully developed bifurcation structure and stability of the mixed convection in rotating curved ducts of square cross-section with the emphasis on the effect of buoyancy force. The rotation can be positive or negative. The fluid can be heated or cooled. The study reveals the rich solution and flow structures and complicated stability features. One symmetric and two symmetric/asymmetric solution branches are found with seventy five limit points and fourteen bifurcation points. The flows on these branches can be symmetric, asymmetric, 2-cell, and up to 14-cell structures. Dynamic responses of the multiple solutions to finite random disturbances are examined by the direct transient computation. It is found that possible physically realizable fully developed flows evolve, as the variation of buoyancy force, from a stable steady multicell state at a large buoyancy force of cooling to the coexistence of three stable steady multicell states, a temporal periodic oscillation state, the coexistence of periodic oscillation and chaotic oscillation, a chaotic temporal oscillation, a subharmonic-bifurcation-driven asymmetric oscillating state, and a stable steady 2-cell state at large buoyancy force of heating.

scholarly journals Improved Energy Efficiency of Mixed Convection Heating Process in Eccentric Annulus

2021 ◽  
Vol 13 (8) ◽  
pp. 168781402110391
Author(s):  
Ben Abdelmlek Khaoula ◽  
Ben Nejma Fayçal
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Rayleigh Number ◽  
Mixed Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Rotation Speed ◽  
Numerical Study ◽  
Heating Process ◽  
Eccentric Annulus

This paper deals with a numerical study of mixed convection heat transfer in horizontal eccentric annulus. The inner cylinder is supposed hot and rotating, however the outer one is kept cold and motionless. The numerical problem was solved using COMSOL Multiphysics® which is based on finite element method. The resolution of the partial differential equations was conducted through an implicit scheme with the use of the damped Newton’s method. The present numerical analysis concerns the effect of eccentricity, rotation speed and Rayleigh number on the flow patterns, heat transfer rate, and energy efficiency of the process. It was found that the heat transfer rate increases with the increase of Rayleigh number. In addition, the heat transfer rate drops with the increase of rotation speed. Finally, we have demonstrated that maximum energy efficiency is achieved not only with higher Rayleigh number but also it is maximum with small eccentricity.

Numerical study of mixed convection heat transfer inside a vertical microchannel with two-phase approach

2018 ◽  
Vol 135 (2) ◽  
pp. 1119-1134 ◽  
Author(s):  
Mohammad Reza Tavakoli ◽  
Omid Ali Akbari ◽  
Anoushiravan Mohammadian ◽  
Erfan Khodabandeh ◽  
Farzad Pourfattah
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Two Phase ◽  
Phase Approach ◽  
Mixed Convection Heat Transfer ◽  
Vertical Microchannel

scholarly journals Numerical Investigation of Mixed Convection and Entropy Generation in a Wavy-Walled Cavity Filled with Nanofluid and Involving a Rotating Cylinder

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 664 ◽  
Author(s):  
Ammar Alsabery ◽  
Muneer Ismael ◽  
Ali Chamkha ◽  
Ishak Hashim
Keyword(s):  
Heat Exchange ◽  
Rayleigh Number ◽  
Heat Source ◽  
Mixed Convection ◽  
Volume Fraction ◽  
Numerical Study ◽  
Rotational Velocity ◽  
Geometrical Parameters ◽  
Galerkin Finite Element ◽  
Vertical Walls

This numerical study considers the mixed convection and the inherent entropy generated in Al 2 O 3 –water nanofluid filling a cavity containing a rotating conductive cylinder. The vertical walls of the cavity are wavy and are cooled isothermally. The horizontal walls are thermally insulated, except for a heat source segment located at the bottom wall. The dimensionless governing equations subject to the selected boundary conditions are solved numerically using the Galerkin finite-element method. The study is accomplished by inspecting different ranges of the physical and geometrical parameters, namely, the Rayleigh number ( 10 3 ≤ R a ≤ 10 6 ), angular rotational velocity ( 0 ≤ Ω ≤ 750 ), number of undulations ( 0 ≤ N ≤ 4 ), volume fraction of Al 2 O 3 nanoparticles ( 0 ≤ ϕ ≤ 0.04 ), and the length of the heat source ( 0.2 ≤ H ≤ 0.8 ) . The results show that the rotation of the cylinder boosts the rate of heat exchange when the Rayleigh number is less than 5 × 10 5 . The number of undulations affects the average Nusselt number for a still cylinder. The rate of heat exchange increases with the volume fraction of the Al 2 O 3 nanoparticles and the length of the heater segment.

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