الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 144 |  |  |
| | | from | 144 | | |
Abstract
The objective of the present work is to study the laminar heat transfer from an infinite isothermal horizontal circular cylinder. The heat transfer from the cylinder, which can be by either nntural . forced or combined convection wn~ ~tudicd numerically. The conservation equations governing the transfer of mass, momentum and energy in the cylindrical coordinate system were solved by the Patankar and Spalding technique [I] . A single correlation solution was obtained in the case of natural convection in the range of the Rayleigh number from 102 to 107 and Prandtl number from 0.1 to 100 , and forced convection for air in the range of the pure forced convection Reynolds number from I to 500 . In the case of combined convection in air ,the governing equations revealed that the Nusselt number depends on the forced flow Reynolds number and Richardson number. Through the definition of an effective Reynolds number , obtained by combining vectorially the natural and forced convection , it was possible in the case of the assisting flow to eliminate the separate effect of the forced convection Reynolds number in the final correlation. The effective Reynolds number, ranged from 2 to 2200 . On the contrary, in the case of the opposing flow and due to the existence of different flow regimes which depend on the magnitude of the effective Reynolds number, it was impossible to cast the results in a single correlation. The concept of effective Reynolds number which succeeded in eliminating the separate effect of the forced convection Reynolds number in case of assisting flow has failed to do so with the opposing flow. Separate correlating equations were derived for the different forced convection Reynolds number.