Bifurcation and stability of forced convection in curved ducts of square cross-section

2004 ◽  
Vol 47 (14-16) ◽  
pp. 2971-2987 ◽  
Author(s):  
Liqiu Wang ◽  
Tianliang Yang
Keyword(s):  
Forced Convection ◽  
Cross Section ◽  
Curved Ducts ◽  
Bifurcation And Stability

Local thermal non-equilibrium conjugate forced convection and entropy generation in an aircraft cabin with air channel partially filled porous insulation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Oktay Çiçek ◽  
A. Cihat Baytaş
Keyword(s):  
Thermal Conductivity ◽  
Reynolds Number ◽  
Forced Convection ◽  
Cross Section ◽  
Entropy Generation ◽  
Channel Wall ◽  
Darcy Number ◽  
Content Type ◽  
Exit Cross Section ◽  
Air Channel

Purpose The purpose of this study is to numerically investigate heat transfer and entropy generation between airframe and cabin-cargo departments in an aircraft. The conjugate forced convection and entropy generation in a cylindrical cavity within air channel partly filled with porous insulation material as simplified geometry for airframe and cabin-cargo departments are considered under local thermal non-equilibrium condition. Design/methodology/approach The non-dimensional governing equations for fluid and porous media discretized by finite volume method are solved using the SIMPLE algorithm with pressure and velocity correction. Findings The effects of the following parameters on the problem are investigated; Reynolds number, Darcy number, the size of inlet and exit cross-section, thermal conductivity ratio for solid and fluid phases, angle between the vertical symmetry axis and the end of channel wall exit and the gap between adiabatic channel wall and horizontal adiabatic wall separating cabin and cargo sections. Originality/value This paper can provide a basic perspective and framework for thermal design between the fuselage and cabin-cargo sections. The minimum total entropy generation number is calculated for various Reynolds numbers and thermal conductivity ratios. It is observed that the channel wall temperature increases for high Reynolds number, low Darcy number, narrower exit cross-section and wider the gap between channel wall and horizontal.

Analytical Solution of Forced Convection in a Duct of Rectangular Cross Section Saturated by a Porous Medium

2005 ◽  
Vol 128 (6) ◽  
pp. 596-600 ◽  
Author(s):  
Kamel Hooman ◽  
Ali A. Merrikh
Keyword(s):  
Porous Medium ◽  
Forced Convection ◽  
Cross Section ◽  
Viscosity Ratio ◽  
Rectangular Cross Section ◽  
Darcy Number ◽  
Uniform Heat Flux ◽  
Brinkman Model ◽  
Type Solution ◽  
Series Type

A theoretical analysis is presented to investigate thermally and hydrodynamically fully developed forced convection in a duct of rectangular cross section filled with a hyper-porous medium. The Darcy-Brinkman model was adopted in the present analysis. A Fourier series type solution is applied to obtain the exact velocity and temperature distribution within the duct. The case of uniform heat flux on the walls, i.e., the H boundary condition in the terminology of Kays and Crawford (1993, Convective Heat and Mass Transfer, 3rd ed., McGraw-Hill, NY), is treated. Values of the Nusselt number and the friction factor as a function of the aspect ratio, the Darcy number, and the viscosity ratio are reported.

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