Chimney effect due to different vertical position of an isothermal horizontal cylinder confined between two adiabatic walls
- Mechanical Engineering Department, University of Tehran, Tehran (Iran)
The variation of natural convection heat transfer from an isothermal horizontal cylinder confined between two adiabatic walls of constant height is investigated by Mach-Zehnder interferometry technique. This paper focuses on the chimney effect due to the vertical position changes of cylinder (Y) located between two walls with a constant distance of W measuring 1.5 cylinder diameter. The cylinder's local and average Nusselt numbers are determined for ratio of vertical position to its diameter ranging from Y/D = (0 to 10), and the Rayleigh number ranging from 3.5 x 10{sup 3} to 1.4 x 10{sup 4}. There is an optimum distance between the walls in which the Nusselt number is maximum. Results are indicated with a single correlation which gives the average Nusselt number as a function of the ratio of vertical position to cylinder diameter and the Rayleigh number. The experimental data shows that there is an optimum vertical position for the cylinder at which the Nusselt number has a maximum value at each Rayleigh number. This optimal vertical position is derived from the correlation and is presented by an equation. The value of the optimum vertical position increases as the Rayleigh number increases. (author)
- OSTI ID:
- 21169011
- Journal Information:
- Experimental Thermal and Fluid Science, Vol. 33, Issue 4; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of confining walls on heat transfer from a vertical array of isothermal horizontal elliptic cylinders
Experimental study of natural convection heat transfer from vertical array of isothermal horizontal elliptic cylinders