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).
يتناول البحث تعليم اللغة العربية وما لها من أثر بين التراث والمعاصرة إذ يعُد مقياس رقي أي مجتمع من المجتمعات مقدار عنايته بلغته القومية ، فهي وسيلته واداته للتفاهم في مواجهة المواقف المختلفة التي تتطلب الكلام ، والاستماع ، والقراءة ، والكتابة ، هي دلالة تحضره وتقدمه في احواله المختلفة ، وهي الشرط الاساس في بقائه ونمائه ، فبدونها يغيب موضوع الحديث عن مفهوم المجتمع القومي لاي شعب من الشعوب ..
The over mentioned subject is considered most important subject hugely being concerned over , since it provides sensual experiences that hardly be fulfilled under the natural conditions of teaching experience; besides , it could surpass obstacles that impede the process of explanation if only depending on the reality. By this means , it could merge more than one sense to get the information to the students 'mind
العلاقة بين السلطات الثلاث والدستور العراقي
العلاقات السياسية بين الوطن العربي وفرنسا
موسيقى الشعر العربي بين الطبع والصنعة
We have studied in this research litter (Taa) a morphological , sonic indicative and comparative study among four Semitic languages. They are Arabic , Hebrew, Syriac and Akkadian languages . We have divided the research into a number of pivots beginning with an entrance about the letter (Taa) in Semitic languages and the symbols which are used by these languages referring to . Then we have studied (Taa) from sonic side with letters phenomenon (b, g, k, p, t) the six in both Hebrew and Syriac languages . The letter (Taa) is formed one of them and the sonic change that is happening in articulation (Taa) according to sonic rules related to these letters in case of emphasis or in case of neglected (not emphasis). Then we have studied the pro
... Show Moreتلعب المؤسسات المصرفية دورا مهما و رئيسيا في اقتصاد أي بلد من خلال قيامها في تعبئة مدخرات المجتمع و من ثم توجيهها نحو الفرص الاستثمارية المختلفة التي تزيد من معدلات النمو الاقتصادي و التوظيف الكامل للموارد وكما هو معروف فأن الجهاز المصرفي يؤدي مهام اقتصادية تخضع للتغيرات المستمرة و على الرغم من ان وظائفه التقليدية لازالت على حالها ألا وهي قبول الودائع و منح القروض و التسهيلات الائتمانية نجد أن الوسائل و
... Show MoreThe research discusses the problem of salaries in the public sector in terms of the process of analyzing its structure and the possibility of benefiting from the information provided by the analysis process for the strategic planning process, and the General Authority for Groundwater has been adopted and one of the formations of the Ministry of Water Resources, which is centrally funded, to represent the salary structure of its employees (1117) employees be a field of research, as the salary structure in it was analyzed for the period between (2014-2019) using the quantitative approach to analysis and by relying on a number of statistical tools in the analysis process, including mathematical circles, upper limits, lower limits, p
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There are many problems facing the economic entities as a result of its mass production &variation of its products , the matter which had increased the need & importance of cost accounting which is regarded a main tool for the managerial control.
The actual costing system is unable to meet the contemporary management needs ,so the Standard costing system appear to provide the management with required information to perform its functions by the best use& way.
This research aims to determine the standard cost for the direct material for oil extraction activity by applying it in the north oil company.