A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave number (1 & 0.75) for Rayleigh number of (1000).
تكمن مشكلة البحث بان المؤسسات عامةـ والتعليمية منها خاصةفي الوقت الحاضرتواجه ظروف بيئيةتفرض عليها حتمية التغيير ، وذلك بسبب التحولاتالتي تحدثفي عالمناالحالي سواءًكان على المستوىالمحلي أو العالمي أو على المستوىالمؤسسة نفسها مما يجعلمؤسساتنا التربويةبحاجةملحةلمواجهة هذا التغيير القادم وذلك من خلال معالجةالمشكلاتالتي قد تظهر بطرق مبتكرة وابداعية مغايرةللطرقالتقليدية ،وذلك من خلال تهيئة المناخ الت
... Show Moreيُعد الذكاء الاصطناعي من العلوم الحديثة التي ارتبطت بالإنسان منذ العقود الخمسة الماضية، وأصبحت السياسة الرقمية جزءاً لا يتجزأ من المجتمع لكونها تُستعمل في أغلب مجالات حياة الإنسان. وهذا ما شجع صانعي السياسات التكنولوجية الجديدة في التفكير بكيفية توظيفه لخدمة مصالحهم العليا السياسية والاقتصادية، بغض النظر عن بذل الجهود للتفكير في تنظيمهم للذكاء الاصطناعي التوليدي، ووضع قيود تراعي التشريعات الدينية، وقوا
... Show MoreAbstract
All the economic units whether productive or service units , strive to achieve specific objectives , their presence and continuity depend on them and the quality of the performance and service present to the society . This units to be able to achieve their objectives , must own basic assets to perform the activities , and apply laws , systems , and instructions , in addition to legal , managerial , and financial authorities . So this units to endeavor maintain this assets , in addition to sound application of laws ,systems . and procedures to enhance their performance . For this purpose arise the role of internal control and internal check in maintenance of assets and sound application of&n
... Show More
تحليل الأخطاء الصوتية في بعض كتب اللغة الروسية الدراسية
The study present a detailed description of the new violent situation that those women faced after 2003 in Iraqi society and the effect of such violence and security breaking down on minority women perception and feeling of bonding or adaptation with this society and how they look to the aaceptance of the society to them and their minority group as a whole. In addition to the impact of these social changes after 2003,on the women rights and personal freedom. One of the aims of the study is to provide data base to be used when efforts present to put a policies or programs for supporting the minority women. Another aim is to point out and define the violations commited on the rights of those women. The field survey included 2100 women from
... Show Moreالحركات الاسلامية في ظل الوضع الدولي الجديد
The Research aimed for identification the significant of health problems that occurrences through
misused of computer for those whom attaches with more than two hours daily and to identification the
nature of demographical characteristics variables and that related variables with using computer. Also to
know the level of user’s knowledge for some attaché’s equipment's and finally creating a new suggested
measurement scale for studying health problems that were occurred through misused of computer.
Creating questionnaire includes several domains (Social problems – family environment, Social problems –
external environment, some health problems attaches with related equipment's, psychological problems,
and hea
This study deals with the region of the Babylon governorate in Iraq during the Proto-Literate and Early Dynastic periods. It is the region of the well- known ancient capital Babylon. The earlier period includes Late Uruk, Jamdat nasr, and the first epoch of the Early Dynastic period. The latter includes the second and third epochs of the Early Dynastic period. The both periods had lasted more than one thousand years (3500-2334 BC
The present research deals with the influencing factors which depends on the way perceptual of the graphic designer which enters in the design logos of the loco European health, where the search include four chapters, the researcher reviewed in the chapter 0ne the methodical frame of the research ,as reviewed in the second chapter the theoretical frame, and the previous studies which included three sections, the first section included the perceptual understandable and types of it, and the second section included the influencing factors in the designer perceptual ways and its division . While the third section included the perceptual in graphic designer through the percepted shapes and the relation with ground and colors for express the i
... Show More