An experimental and numerical study was carried out to investigate the heat transfer by natural convection in a three dimensional annulus enclosure filled with porous media (silica sand) between two inclined concentric cylinders with (and without) annular fins attached to the inner cylinder under steady state condition. The experiments were carried out for a range of modified Rayleigh number (0.2 ≤Ra*≤ 11) and extended to Ra*=500 for numerical study and for annulus inclination angle of (δ = 0˚, 30˚, 60˚ and 90˚). The numerical study was to give the governing equation under assumptions that used Darcy law and Boussinesq’s approximation and then it was solved numerically using finite difference approximation. It was found that the average Nusselt number depends on (Ra*, Hf, δ and Rr ). The results showed that the increasing of the fin length increases the heat transfer rate for any fin pitch unless the area of the inner cylinder exceeds that of the outer one; then the heat will be stored in the porous media. A comparison was made between the results of the present work and those of other researches for the case without fins and excellent agreement was obtained.
Laminar Free Convection in Three Dimensional Inclined Porous Annulus with Fins on the Inner Cylinder
natural convection
three dimensional
inclined annulus
porous media and annular fins. Iraqi Journal of Chemical and Petroleum Engineering University of Baghdad College of Engineering
Publication Date
Tue Oct 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
الادارة بالرؤية المشتركة وانعكاساتها على التسويق الابداعي بحث استطلاعي لعينة من موظفي الشركة العامة للصناعات الكهربائية
الادارة بالرؤية المشتركة
التسويق الابداعي
الاتصال الفعال
الرؤية بالاعتقاد
المراقبة الفعالة
الطلاقة والمرونة
الاصالة.
for research: shared vision management
creative marketing
effective communication
belief in belief
effective control
fluency and flexibility
originality
ان السبب الرئيسي لاختيار الموضوع كونه من الاساليب الادارية الحديثة التي تهدف الى انجاح المنظمة او الشركة المبحوثة, اذ تمثلت مشكلة البحث في ما دور الادارة بالرؤية المشتركة في تعزيز التسويق الابداعي بالشركة المبحوثة, يهدف البحث الى تسليط الضوء على مفهوم الادارة بالرؤية المشتركة وانعكاساتها على التسويق الابداعي للمنظمة ، باعتبارها منهج اداري حديث يسهم في تغيير وتجديد وتطوير واقع المنظمة المبحوثة( الشرك
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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Preparation and Identification of some new Pyrazolopyrin derivatives and their Polymerizations study
Synthesis
Fused Pyrazoles
1-(3
6-dimethyl-4-oxo-1
4-dihydro-5H-pyrazolo [4
3-C] pyridin-5-yl)-1H-pyrrole-2
5-Dione S1
1-[2-(3
6-dimethyl-4-oxo-1-phenyl-1
4-dihydro-5H-pyrazolo[4
3-C]pyridin-5-yl)ethyl]-1H-pyrrole-2
5-DioneS2 and 1-(3
6-dimethyl-4-oxo-1-phenyl-1
4-dihydro-5H-pyrazolo[4
3-C]pyridin-5-yl)-1H-pyrrole-2
5-Dione S3
reactivity ratios
copolymer composition
Mean Sequence lengths.
Preparation and Identification of some new Pyrazolopyrin derivatives and their Polymerizations study