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3-D Air Flow in a Toroidal Natural Convection Loop
| International Journal of Computer Applications |
| Foundation of Computer Science (FCS), NY, USA |
| Volume 121 - Number 8 |
| Year of Publication: 2015 |
| Authors: Manal H. Saleh |
10.5120/21561-4594
|
Manal H. Saleh . 3-D Air Flow in a Toroidal Natural Convection Loop. International Journal of Computer Applications. 121, 8 ( July 2015), 24-29. DOI=10.5120/21561-4594
Abstract
Heat transfer characteristics of air flows in concentric toroidal annular tubes filled with porous media were numerically investigated. The toroidal annulus is constant walls temperature where the outer wall temperature is lower than the inlet temperature. The numerical methodology was based on the finite difference approximation method. The computations were performed for vertical and horizontal toroidal ring, four toroidal length and four radius ratios cases for a modified Rayleigh number range (10≤Ra≤5000). The inner tube radius ranged from 0. 15 to 0. 4 m with the radius ratios Rr 0. 333, 0. 555, 0. 777 and 0. 888 and a length of 0. 05, 0. 1, 0. 15 and 0. 2m. The local Nusselt number in the angular direction for both walls and the average Nusselt number in concentric toroidal annular tubes were obtained. In addition the isothermal lines and the streamlines were investigated. The results show that The vertical toroidal loop is more suitable than the horizontal one because the heat transfer is less so the temperature values will be higher and remain high for a longer time which is required in such devices The best design of such devices is to take L=0. 05 with inner radius of 0. 15 m and to use it at δ =0 (vertical)
References
- G. D. Raithby, K. G. T. Hollands, Natural convection, in: W. M. Rohsenow et al. (Eds. ), Handbook of Heat Transfer, third ed. , McGraw-Hill, New York, 1998 (Chapter 4).
- H. Manal saleh, Enhancement of Heat Transfer in Horizontal Annulus Filled with Porous Media under Constant and Periodic Boundary Conditions, Journal of Mechanical Engineering. Photon 124 (2014) 198-209.
- Dalia Sabina Cimpean, Ioan Pop, Fully developed mixed convection flow of a nanofluid through an inclined channel filled with a porous medium, International Journal of Heat and Mass Transfer 55 (2012) 907–914.
- H. Saleh, R. Roslan, I. Hashim, Natural convection heat transfer in a nanofluid-filled trapezoidal enclosure, International Journal of Heat and Mass Transfer 54 (2011) 194–201.
- El Hassan Ridouane , Christopher M. Danforth, Darren L. Hitt, A 2-D numerical study of chaotic flow in a natural convection loop, International Journal of Heat and Mass Transfer 53 (2010) 76–84.
- Carlo Alberto Tiberio, Luigi Raganella, Germana Banci, Cafiero Franconi, The RF Toroidal Transformer as a Heat Delivery System for Regional and Focused Hyperthermia, IEEE Transactionson Biomedical Engineering. Vol. 35, No. 12, December 1988.
- G. Refai-Ahmed, M. M. Yovanovich, D. Cooper, Heat Transfer Modelling of Toroidal Inductors: Effect of Orientations, IEEE Intersociety Conference on Thermal Phenomena 1998.
- Nield D. A. , Bejan A. , 1999. Convection in Porous Media, Springer-Verlag, New York.
- Fukuda K. , Takata Y. , Hasegawa S. , Shimomura H. and Sanokawa K. , 1980, Three – Dimensional Natural Convection in a Porous Medium Between Concentric Inclined Surfaces, Proc. 19th Natl Heat Transfer Conf. , Vol. HTD –8, 97 – 103.
- Wang Bu – Xuan and Zhang Xing, 1990, Natural Convection in Liquid Saturated Porous Media Between Concentric Inclined Surfaces, Int. J. Heat and Mass Transfer Vol. 33. No 5, 827-833.
- Aziz K. and Hellums J. D. , 1967, Numerical Solution of the Three Dimensional Equations of Motion for Laminar Natural Convection, The Physics of Fluids, Vol. 10, No. 2, 314 – 324.
- H. Manal AL- Hafidh, A. Khawla AL Zubaidy, Heat Transfer Investigation of TiO2 Nanofluid in Silica Aerogel/Glass Fiber Composite Material Enclosure, International Journal of Computer Applications, Vol. 112- No. 8, February 2015.
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