Created for presentation of Seminer course of MSc Engineering

1. Free Convection Cooling in
Modified L-Shape Enclosures
Using Copper Water Nanofluid
Majid Saidi, Gholamreza Karimi
Department of Chemical Engineering, Shiraz University, Iran
Sayed Rasul
1015102008
Journal of Energy, 2014

2. Introduction
The study examines the effect of various
operating and design parameters such
as Rayleigh number, geometry and the
volume fraction of copper nanoparticles
on the free convection characteristics
within an L-shaped enclosure filled with
nanofluids. The enclosure geometry was
modified by insertion of a few round pins
and by inclination to study their effects on
the rate of heat transfer.

3. Objective
The aim of the present study is
investigation of free convection cooling in
an L-shape enclosure filled with copper-
water nanofluid. The effects of the volume
fraction of the Cu nanoparticles, Rayleigh
number and the aspect ratio of the L-
shaped enclosure on the heat transfer
coefficient, temperature and velocity
profiles are studied.

4. Physical Model

5. Mathematical Model

6. Non-Dimensional Form

7. Boundary Condition
Aspect Ratio

8. Results- Isotherms
AR=0.2
ᵠ=0.03
AR=0.2
ᵠ=0.01

9. AR=0.2
ᵠ=0.03
AR=0.2
ᵠ=0.1

10. AR=0.4
ᵠ=0.03
AR=0.4
ᵠ=0.03

11. AR=0.4
ᵠ=0.03
AR=0.2
ᵠ=0.03

12. Velocity Profiles
AR=0.2
ᵠ=0

13. AR=0.2
ᵠ=0.03
AR=0.2
ᵠ=0.1

14. AR=0.2
ᵠ=0.06
AR=0.4
ᵠ=0.06

15. AR=0.4
ᵠ=0.03
AR=0.4
ᵠ=0.1

16. Heat Transfer Coefficient
AR=0.2
ᵠ=0.03
AR=0.2
ᵠ=0.1

17. AR=0.2
ᵠ=0.06

18. AR=0.2
ᵠ=0.1
AR=0.4
ᵠ=0.1

19. Performance analysis of the modified L-shape enclosure
Isotherms
AR=0.4
ᵠ=0.1

20. AR=0.4, ᵠ=0.1
Velocity Profile

21. AR=0.4
ᵠ=0.1
Heat transfer coefficient
AR=0.4
ᵠ=0.1

22. Heat transfer coefficient at Inclination
45˚ 135˚
225˚ 315˚

23. Conclusion
• Numerical results indicate that the presence of Cu
nanoparticles in pure water can significantly enhance
heat transfer coefficient.
• At low Rayleigh numbers, the fluid in the horizontal
section of the enclosure is almost stagnant and the
dominant heat transfer mechanism is conduction.
• Transition from pure conduction to free convection
occurs at Rayleigh number ranging from 105 to 106.
• Decreasing Rayleigh number and increasing aspect ratio
can enhance the heat transfer coefficient in the enclosure.
• The results have revealed that the application of
cylindrical pins inside the enclosure can enhance heat
transfer rate.
• The study of the effect of inclination angle has shown that
there exists an optimum angle (ω=225˚) for which the heat
transfer coefficient is maximum.

24. Thanks to all
for your kind
Attention
