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Article
DEVELOPMENT SEMI-EMPIRICAL FORMULA TO PREDICT MASS FLOW RATE OF WORKING FLUID WITHIN THERMOSYPHON LOOP

Authors: Basim Hammed Freegah --- Khalil Ibrahim Abass --- Ammar Abdullah Hussain
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2018 Volume: 22 Issue: 2 (part-6) Pages: 141-149
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

In this study, detailed investigations of the natural convection phenomenon in a single-phase thermosyphon cycle have been carried out employing an advanced Computational Fluid Dynamics (CFD) based techniques. The investigations have included the effects of increasing the number of risers and increasing the risers’ length with the constant diameter under various values of heat flux, on the rate of mass flow of the working fluid in the cycle of thermosyphon. A value of instantaneous solar heat flux has been applied at the beginning of each time step. The results have shown that the heat flux, the increasing the risers’ length and number of riser pipes have important effects on the mass flow rate of the working fluid within the thermosyphon cycle. Furthermore, the rates summation of the mass flow of the working fluid passing at all risers is equal to the rate of mass flow through the downcoer pipe. In equation to predict Re number and hence calculate the rate of mass flow of the working fluid in the thermosyphon cycle has been established. An addition, the developed equation can give an average percentage difference of 8%. Therefore, this equation can be used with approximately 92 % of accuracy


Article
Numerical and Experimental Study of CPU Cooling with Finned Heat Sink and Different P.C. Air Passages Configurations
دراسة التجریبیة و العددیة لتبرید وحدة المعالجة المركزیة مع مشتت حراري ذو زعانف باستخدام اشكال مختلفھ لاماكن دخول الھواء للحاسوب المكتبي

Authors: Jalal M. Jalil جلال محمد جلیل --- Ekbal H. Ali اقبال حسین علي --- Hiba H. Kurdi ھبھ ھادي كردي
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2018 Volume: 21 Issue: 1 Pages: 99-107
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

This study investigated numerically and experimentally fluid flow and heat transfer in the desktop PC. Three patterns of the positions of air inlet and outlet were tested to find the best one for cooling. The computer components in the present study are CPU, finned heat sink, power supply, motherboard, CD, HDD and fans. Three components which were generate heat are CPU, motherboard and power supply and there were two openings for air inlet and two for air outlet. The air inlet velocities were 1.2, 1.8, 2.4 m/s with constant CPU fan velocity. The studied parameters were the changed of inlet air velocity, powers of CPU, motherboard and PSU and the positions of inlet air. The numerical results obtained are found in a good agreement with the experimental results. The experimental results show that the maximum temperature was 81℃ at 16.5 W and 1.2 m/s. Numerical results showed that the CPU temperature reaches 89.6 ℃ at 18.5 W and 1.2 m/s. From the results, it was found that; the temperatures of the main components (PSU and motherboard) affected little by CPU power and vice versa, the finned heat sink has higher cooling efficiency and the pattern 1 was the best pattern for CPU cooling.


Article
Numerical and Experimental Study of Cooling in Desktop Computer with Block Heat Sink

Authors: Jalal M. Jalil --- Ekbal H. Ali --- Hiba H. Kurdi
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 4 Part (A) Engineering Pages: 430-438
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper investigates numerically and experimentally fluid flow and heat transfer inside the desktop P.C.. The study of cooling considers the components; CPU, heat sink, power supply, motherboard, CD, HDD and fans. Three components have heat source (CPU, motherboard and power supply unit). There were two openings for air inlet and two for air outlet. The tested values of air inlet velocities were 1.2, 1.8 and 2.4 m/s. The work investigates the effect of inlet air velocity and powers (PCPU = 8.5 W, PPSU = 24 W, PMO=12 W) of multi-components (CPU, motherboard and PSU). The numerical results obtained (by finite volume method CFD) are found in a good agreement with the experimental results. The results show that the highest temperature for CPU with block heat sink was 88.1℃ (PCPU = 8.5 W, PPSU = 24 W, PMO=12 W), the temperature of the heat generation components decreases linearly with increases of inlet air velocity. The CPU temperature increases with CPU power linearly. Motherboard temperature was the lowest one due to its position and area (52oC). Full details of flow field and temperature distribution are shown.


Article
CFD Study of Cuttings Transport through Vertical Wellbore
دراسة حركيات المائع الحسابية لقطع الصخور المنتقلة خلال بئر عمودي

Authors: Mortatha Al-Yasiri --- Amthal Al-Gailani --- Dongsheng Wen
Journal: Journal of Petroleum Research & Studies مجلة البحوث والدراسات النفطية ISSN: 22205381 Year: 2018 Issue: 20 Pages: 158-178
Publisher: Ministry of Oil وزارة النفط

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Abstract

Cuttings transportation from the bit up the annulus to the surface is one the essential functions that are performed by drilling fluid. Predication of drilling fluid efficiency to transport cuttings in the annulus is very complicated due to numerous parameters that have affected drilling operations. Computational Fluid Dynamics (CFD) is widely used as a numerical technique in handling complex multiphase flow problems in different operational conditions. The present work has taken the advancement of CFD to computationally analyse the influence of the effects of various parameters like drilling fluid rheology, flow rate, pipe rotation, cuttings density, shape, concentration and drilling fluid- cuttings particle coupling regimes on the cuttings transport in a vertical wellbore. The CFD simulation was carried out by using transient solver of ANSYS-FLUENT CFD commercial code. The dense discrete phase model (DDPM) is suggested in this work to overcome the main shortcomings of Eulerian–Eulerian and CFD-DEM approaches in simulating drilling fluid-cuttings flow. Also, some of the experimental investigations were involved in determining the fluid physical properties and essential input data to perform the CFD simulations. Regarding the results validation and verification, well agreement has been achieved between results obtained in this study with those reported in other studies.


Article
Integration of Optimum Power for Wind Turbine Blade atDifferent Cross Section

Authors: Muhammad .A.R Yass --- Saadi Turied Kurdi --- Mahmood Abdulzahra Shkara
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2018 Volume: 26 Issue: 7 Pages: 124-149
Publisher: Babylon University جامعة بابل

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Abstract

This research analysis and optimizes the main wind horizontal turbine blade parameters for high-performance altitude with variable pitch blade angle for different blade cross-section unsymmetrical airfoil NACA 4412 and unsymmetrical airfoil supercritical Eppler 417. For deep specification, some wind horizontal turbine parameters kept constant through the proses method to integrate thehighest behavior of windmill turbine power coefficient. The procedure analysis with FORTRAN.90 code ,then compare with German code and then optimized using Schmitz and Betz method for blade chord and lift to drag for blade pitch angle. From theoretical results discussion, important conclusions figured; also arecommendation for further work was suggested.Best optimization methods were Schmitz chord optimization and Lift/Drag twist optimization which increases the Cp 10.3% for Eppler 4417 and 9.5% for NACA 4412.All results were tabulated and plotted for all optimization results

البحث يقوم بتحليل وتحسين براميترات الخاصة بتورباين رياح افقي ذو اداء عالي المستوى مع تغير زاوية خطوة الريشة لمقاطع مختلفة من الريش ذو مطيار غير متماثل نوع (NACA 4412) وكذلك لمطيار غير متماثل انشطاري نوع (EPPLER 417) ومن اجل دقة أكثر تم تثبيت بعض البرامترات خلال التحليل لكي يتم التكامل والحصول على اعلى معامل قدره لتوربين الرياح. تم اجراء التحليل باستعمال برنامج (FORTRAN 90)تم المقارنة مع برنامج الماني ثم تم تحسين الاداء باستعمال طريقة شمز وبيتز الخاصة لوتر الريشة وكذلك الخاصة بالرفع والكبح ولزاوية خطوة الريشة من مناقشة النتائج النظريه تم توضيح ورسم الاستنتاجات المهمة وكذلك عمل توصيات ومقترحات مستقبلية. من خلال النتائج وجد قيم معامل القدرة ازدادت بمقدار (10.3%) لمطيار انشطاري نوع (EPPLER417)و(9.5%) لمطيار غير متماثل نوع (NACA 4412).


Article
Power optimization of wind mill turbine blade for different cross section

Authors: Muhammad A.R Yass --- Hussein Ali Hussein --- Mahmood Abdulzahra Shkara
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2018 Volume: 26 Issue: 2 Pages: 127-134
Publisher: Babylon University جامعة بابل

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Abstract

The aim of this paper was to attain best optimization for twist angle and the chord of wind mill blade by using CFD code with Schmitz, Betz and .Lift to drag twist optimization along with Genetic Algorithm method. The technical point of view to change the cross section of the blade by using symmetry airfoil (NACA-0012), unsymmetrical airfoil (NACA-4412) and supercritical airfoil (Eppler-417). The best optimization Method was Schmitz chord optimization and lift to drag for twist optimization which increase the Cp 10.3% for Eppler 417 , 9.5% for NACA 4412 and 16% for NACA 0012. All results were plotted and tabulated for all optimization results.

الهدف من هذا البحث هو الحصول على زاويه التواء والوتر الامثل لريشه التوربين الهوائي باستخدام برنامج السوائل الحسابيه الديناميكيه (CFG) والمتضمن نظريه (Schmitz) ونظريه (Betz) وطريقه الرفع الى الكبح (Lift To Drag) باستخدام طريقه ( Genetic Algorithm ) . من وجه النظر الفنيه هو هو تغير المقطع العرضي للريشه باستخدام المطيار المتناظر (Symmetrical) والغير متناظر (Unsymmetrical ) ومطيار ابلر(Eppler-417) في الطرق اعلاه حيث تبين ان نظريه (Schmitz) للوتر الامثل وطريقه الرفع الى الكبح (Lift To Drag) لزاويه الالتواء المثلي هي احسن الطرق لرفع معامل القدره الكهربائيه 10.3% لمطيار ابلر (Eppler-417) و9.5% للمطيار الغير متناظر(Unsymmetrical ) و16% للمطيار الغير متناظر(Symmetrical) . جميع النتائج مثبته بالاشكال والجداول المرفقه .

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