DEVELOPING LAMINAR MIXED CONVECTION HEAT TRANSFER THROUGH VERTICAL CONCENTRIC ANNULI WITH ADIABATIC INNER CYLINDER

محتوى المقالة الرئيسي

Ihsan Y. Hussain
Akeel A. Mohammed
Ghada A. Sadiq

الملخص

Theoretical and experimental investigations have been carried out on developing laminar
combined free and forced convection heat transfer in a vertical concentric annulus with uniformly
heated outer cylinder (constant heat flux) and adiabatic inner cylinder for both aiding and opposing
flows. The theoretical investigation involved a mathematical modeling and numerical solution for
two dimensional, symmetric, simultaneously developing laminar air flows was achieved. The
governing equations of motion (continuity, momentum and energy) are solved by using implicit
finite difference method and the Gauss elimination technique. The theoretical work covers heat flux
range from (200 to 1500) W/m2, Re range from 400 to 2000 and (1.36×105 ≤ Ra ≤ 1.1×107) with
radius ratio of 0.555 which is the same radius ratio used in the experimental part of this study and
Pr=0.7. The experimental work includes construct a rig consists essentially of an annulus with
uniformly heated outer cylinder and adiabatic inner cylinder to give clear insight into heat transfer
process and compare its results with that obtained in theoretical part, the range of the study are
(Re= 383, 724, 1000, 1500) and heat flux equal to (q =370, 422, 588, 980) W/m2. Numerical results
were represented by the temperature profile, axial velocity profile, outer surface temperature and
the distribution of local Nusselt number along the dimensionless axial distance. The velocity and
temperature profile results have revealed that the secondary flow created by natural convection have
significant effects on the heat transfer process. Results reveal also that the experimental local
Nusselt number along the annulus follows the same trend as present theoretical results with mean
difference 10.23 %.

تفاصيل المقالة

كيفية الاقتباس
"DEVELOPING LAMINAR MIXED CONVECTION HEAT TRANSFER THROUGH VERTICAL CONCENTRIC ANNULI WITH ADIABATIC INNER CYLINDER" (2011) مجلة الهندسة, 17(05), ص 1289–1307. doi:10.31026/j.eng.2011.05.19.
القسم
Articles

كيفية الاقتباس

"DEVELOPING LAMINAR MIXED CONVECTION HEAT TRANSFER THROUGH VERTICAL CONCENTRIC ANNULI WITH ADIABATIC INNER CYLINDER" (2011) مجلة الهندسة, 17(05), ص 1289–1307. doi:10.31026/j.eng.2011.05.19.

تواريخ المنشور

المراجع

Collins, "Combined convection in uniformly heated vertical pipe", Heat and mass transfer by combined forced and natural convection, (15th September 1971).

Coney J. E. R. and El-Shaarawi M. A. I. ,"Finite difference analysis for laminar flow heat transfer in concentric annuli with

simultaneously developing hydrodynamic and thermal boundary layers " , Int. Journal for Numerical Method in Engineering, Vol. 9, pp. 17-38, 1975.

El-Shaarawi M. A. and Sarhan A., "Free convection effects on the developing laminar flow in vertical concentric annuli "J. Heat Transfer, Vol. 102, pp.617-622, November, 1980.

Falah A. Aboud, "Combined free and forced convection in an inclined Annulus"، M. Sc. Thesis, University of Basra, College of Engineering, Mechanical Department, 1993.

Hanzawa T., Sako A., Endo H., Kagwa M., Sunaga T. and Koto K., "Combined free and forced laminar convective heat transfer from isothermally heated inner tube in vertical concentric annulus", J. Chemical Engineering of Japan ,Vol. 19 ,No. 1, pp. 78-81 , 1986.

Hashimoto K., Akino N., and Kawamura H., "Combined forced- free convection heat transfer to a highly heated gas in a vertical annulus" ،Int. J. Heat Mass Transfer, Vol.29, No.1, pp. 145-151, 1986.

Heggs and Ingham "Laminar flow combined in vertical annuli", Proceeding of the 8th Int. Heat Transfer Conference, Munchen, Fed. Rep.of Germany, Vol.2, pp. 941-956, 1988.

Kayes .W. M, "Advanced fluid dynamics and heat transfer" Mc Graw-Hill, New York, (1966).

Mohammed. A. R. Nima, Developing laminar mixed convection heat transfer through concentric annuli" M. Sc. Thesis,

University of Baghdad, College of Engineering, Mechanical Department, (2007).

Shaik Samivullah, "Laminar mixed convection in vertical channels" M. Sc. Thesis, King Fahd University of Petroleum

and Minerals, Mechanical Engineering, 2005.

المؤلفات المشابهة

يمكنك أيضاً إبدأ بحثاً متقدماً عن المشابهات لهذا المؤلَّف.

الأعمال الأكثر قراءة لنفس المؤلف/المؤلفين

<< < 1 2 3 > >>