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).
Oil industry played a major role in delineating the course and type o development in both imported and exported Arabic countries alike where its revenues has perform an essential role in forming programs and plans of development on both national and international level in addition to anticipation of future consuming.
Iraq, as an oil producer country with a revenues –based economy depends on oil in building its economy totally including its infrastructure having a the greatest conformed reservoir which make the government budget depends largely on oil revenues where its strategic importance lies in funding all aspects of expenders as it is considered the prime source of foreign currency. The chall
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هدف البحث الى التعرف على تأثير تمرينات خاصة في تطوير بعض القدرات البدنية وانجاز مسابقة عدو(100) متر حواجز تحت (20) سنة. استخدمت الباحثتان المنهج التجريبي بتصميم المجموعة التجريبية ذات الاختبار القبلي والبعدي لملائمته طبيعة البحث. تم تحديد مجتمع البحث بالطريقة العمدية وهم عداءات 100م حواجز من فئة الشباب، واختيار عداءات نادي السليمانية بألعاب القوى وتم اختيار العينة بصورة قصدية بأسلوب الاختبارين القبلي والبعدي و
... Show Moreان مرتكزات السياسة الخارجية العراقية لمرحلة ما بعد العام 2003 قد عكست توجهات ايجابية قادت الى صياغة مجموعة من الرؤى والتصورات الاستراتيجية الجديدة التي افضت الى اعتماد وتوظيف الوسائل والقنوات الدبلوماسية بوصفها وسائل فعالة وبطريقة متكاملة ومتوازنة من اجل تعزيز مستويات الاداء الفعلي وتحقيق جميع الاهداف المستقبلية للسياسة الخارجية العراقية في ضوء صياغة معادلة مفادها: تدعيم وترصين اداء مؤسسات صنع السياسة ال
... Show Moreيُبحر هذا البحث في أغوار نظام تنظيم التجارة الإلكترونية في العراق رقم (4) لسنة 2025، بوصفه تشريعاً استُحدث ليكون جسراً تعبرُ من خلاله الأسواق من نمطية المعاملات التقليدية إلى آفاق المنصات الرقمية العابرة للحدود، ويستقصي البحث بعينٍ ناقدة تلك الهفوات المفاهيمية والتنظيمية التي اعتلت صياغات النظام، لا سيما في اجتراح تعاريف دقيقة للتجارة الإلكترونية والتاجر الإلكتروني، فضلاً عن ارتباك ملامح نطاق السريان، ومتا
... Show MoreThe Andalusi did not leave any poetic art without expressing his psychological and sentimental emotions and the depth of emotions and it sincerity. We found Andalusian translated his emotions into poetry and in many different subjects
The Subject of contritutions to Jerusalemites Scientific in Egypt from 8.5 Century 14.11 AD of noteworthy studies Concern Coming Of these Scientists to Egypt has helped toth to Seek Knowledge and Study or teaching in the tooming w0rid of Science broadly and distinctive through Scientific interaction and intermingling of Civilization between Scientists this Mixing effect of the Scientific life and in tellectal of The nam
... Show Moreعُني العرب منذ القدم بإستعمال الجواهروالأحجار الكريمة ، وإزدادت هذه العناية على مر العصور ، فقد إستعملوا الحلي المتنوعة ، والملابس المطعمة بالجواهر والأحجار الكريمة .
Among the different passive techniques heat pipe heat exchanger (HPHE) seems to be the most effective one for energy saving in heating ventilation and air conditioning system (HVAC). The applications for nanofluids with high conductivity are favorable to increase the thermal performance in HPHE. Even though the nanofluid has the higher heat conduction coefficient that dispels more heat theoretically but the higher concentration will make clustering .Clustering is a problem that must be solved before nanofluids can be considered for long-term practical uses. Results showed that the maximum value of relative power is 0.13 mW at nanofluid compared with other concentrations due to the low density of nanofluid at this concentration. For highe
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