Publication Cover
Numerical Heat Transfer, Part A: Applications
An International Journal of Computation and Methodology
Volume 70, 2016 - Issue 11
334
Views
35
CrossRef citations to date
0
Altmetric
Original Articles

Effects of the inclination angle on natural convection heat transfer and entropy generation in a square porous enclosure

, , &
Pages 1271-1296 | Received 29 Mar 2016, Accepted 13 Aug 2016, Published online: 24 Oct 2016
 

ABSTRACT

In this paper, we analyze numerically the effects of the inclination angle on natural convection heat transfer and entropy generation characteristics in a two-dimensional square enclosure saturated with a porous medium. There is a significant alteration in Nusselt number with the orientation of the enclosure at higher values of Rayleigh number. It reveals that the variation of entropy generation rate with the inclination angle is significant for higher values of Darcy number. The dominant source of irreversibility is due to heat transfer at low values of Darcy number, whereas entropy generation due to fluid flow dominates over that due to heat transfer for larger values of Darcy number.

Nomenclature

Be=

Bejan number

Da=

Darcy number

g=

gravitational acceleration, ms−2

k=

thermal conductivity, Wm−2K−1

K=

permeability of the medium

L=

length of the enclosure, m

Nu=

Nusselt number

Pr=

Prandtl number

Ra=

Rayleigh number

S=

entropy generation rate

T=

dimensionless temperature

T0=

bulk temperature (Th + Tc)/2

u, v=

dimensionless velocity components

x, y=

dimensionless Cartesian coordinates

ρ=

density, kgm−3

α=

thermal diffusivity, m2s−1

β=

volumetric expansion coefficient, K−1

ν=

kinematic viscosity, m2s−1

ϕ=

angle of inclination of the enclosure

ξ=

irreversibility distribution ratio

Subscripts=
avg=

average

c=

cold

h=

hot

T=

total

θ=

heat transfer

μ=

fluid friction

Superscripts=
*=

dimensional quantity

Nomenclature

Be=

Bejan number

Da=

Darcy number

g=

gravitational acceleration, ms−2

k=

thermal conductivity, Wm−2K−1

K=

permeability of the medium

L=

length of the enclosure, m

Nu=

Nusselt number

Pr=

Prandtl number

Ra=

Rayleigh number

S=

entropy generation rate

T=

dimensionless temperature

T0=

bulk temperature (Th + Tc)/2

u, v=

dimensionless velocity components

x, y=

dimensionless Cartesian coordinates

ρ=

density, kgm−3

α=

thermal diffusivity, m2s−1

β=

volumetric expansion coefficient, K−1

ν=

kinematic viscosity, m2s−1

ϕ=

angle of inclination of the enclosure

ξ=

irreversibility distribution ratio

Subscripts=
avg=

average

c=

cold

h=

hot

T=

total

θ=

heat transfer

μ=

fluid friction

Superscripts=
*=

dimensional quantity

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.