References
[1]Kuehn,T.H. and Goldstin, R. J. An Experimental And Theoretical Study Of Natural Convection In The Annulus Between Horizontal Concentric Cylinders , J. Fluid Mech. (1976), Vol. 74, Part 4,Pp.695-719.
[2]Charrir-Mojtabi, M. C., Mojtabi, A. and Caitagirone, J. P. Numerical Solution Of A Flow Due To Natural Convection In Horizontal Cylindrical Annulus J. Heat Transfer, Feb. (1979), Vol. 101, pp.171-173.
[3] Faruak, B. and Guceri, S. I. Laminar And Turbulent Natural Convection In The Annulus Between Horizontal Concentric Cylinders , J. Heat Transfer, Nov. (1982), Vol. 104, Pp.631-636
[4]Kuehn,T.H. and Goldstin, R. J. An Experimental Study Of Natural Convection Heat Transfer In Concentric And Eccentric Horizontal Cylindrical Annuli J. Heat Transfer, Nov. (1978), Vol. 100, Pp. 635-640.
[5] Cho, C. H., Chang, K. S. and Park, K. H. Numerical Simulation Of Natural Convection In Concentric And Eccentric Horizontal Cylindrical Annuli J. Heat Transfer, Nov. (1982), Vol. 104, Pp. 624-630.
Tikrit Journal of Engineering Sciences (2008) 15(1) 51-69
Numerical Study of Natural Convection From Two Parallel Horizontal Cylinders Enclosed by Circular Cylinder
Mahmoud H. Ali |
Mechanical Eng. Dept.-Tikrit University,Iraq. |
Abstract
In this paper, numerical solution is presented for the steady state, two dimensional natural convection heat transfer from two parallel horizontal cylinders enclosed by circular cylinder. The inner cylinders are heated and maintained at constant surface temperature, while the outer cylinder is cooled at constant surface temperature. Boundary fitted coordinate system is used to solve governing equations. The vorticity-stream function and energy equations is solved using explicit finite deference method and stream function equation solved by successive iteration method. (20)Deferent cases are studied cover rang of Rayleigh number from (1,000) to (25,000) based on the inner cylinder diameter. These cases study the effect of the varying inner cylinders position horizontally and vertically within outer cylinder on the heat transfer and buoyancy that causes the flow. Outputs are displayed in terms of streamline, isothermal contours and local and average Nusselt number. The results showed that the position of the inner cylinders highly affects the heat transfer and flow movements in the gap. At low Rayleigh numbers the average Nusselt number increases with increase of horizontal distance between inner cylinders but the state is reversed at high Rayleigh numbers, while the average Nusselt number is increases with inner cylinder moving down at all Rayleigh numbers. The optimal position of inner cylinders for maximum and minimum heat transfer is located at each Rayleigh number so can be employed in isolation process or cooling process.
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Keywords: Natural convection, Horizontal cylinders, numerical analysis