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Experimental and Numerical Research on Flow-Induced Vibration in Valves
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Abstract  

All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of real geometrical, operational, and boundary conditions are simulated to obtain best similarity with real operation conditions. Comparisons performed between experimental data and numerical results (one-way and two-way simulation) to verify the results. The main conclusion was drawn from the study that the dominant source of vibration for valve is the water pulsation in addition to amount of water hammering. In addition, the main source of water pulsation in globe valve is the vortex shedding and pressure difference between upstream and downstream of valve. The vibration amplitude was increased with increasing flow rate until to be maximum when the flow rate around 30% and then decreased until flow rate reaches to around 85% and then trends to be constant.

Keywords: Flow-induced vibration, vortex shedding, pressure pulsation, valve, finite element, ANSYS, fast Fourier transform (FFT).

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Publication Date
Wed Nov 30 2022
Journal Name
Iraqi Journal Of Science
Study of Rod-Plate DC Discharge Plasma Characteristics at Atmospheric-Pressure
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     The characteristics of atmospheric-pressure glow discharge (APGD) produced by rod-plate electrodes are experimentally determined. APGD is sustained by applying a high DC voltage between the electrodes. At atmospheric pressure, the shift from corona discharge to glow discharge is investigated. A rod-plate discharges configuration's volt–ampere properties show the existence of three discharge regimes: corona, glow, and spark. The variations in the electrical field distribution in the various regimes are mirrored in the discharge luminosity. The rod-plate patterns are created under a dark region, and are visible mainly due to the effect of electrons heated by the local enhanced electric field at the interface, according to the op

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Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Field Study of Novel Storage Tank of Solar Water Heating System
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In this paper thermo-hydrodynamic characteristics were investigated experimentally for a new type shell-helical coiled tube heat exchanger used as a storage tank of closed loop solar water heater system. Triple concentric helical coils were made of copper tubes of (12.5mm OD and 10mm ID) with coils diameter of (207, 152.2, 97mm) for outer, middle and inner coils respectively. The experiments were carried out during a clear sky days of (March and April 2012). The parameters studied in this work are: history of average temperature of shell side of the storage tank, collector heat gain, heat rejected from coils to shell side of the storage tank, collector efficiency, thermal effectiveness of the heat exchanger (storage tank), and pressure d

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Publication Date
Tue Sep 27 2022
Journal Name
Arab Science Heritage Journal
آل البيت ( عليهم السلام ) من خلال كتاب درر السمط في خبر السبط لابن الابار البلنسي الاندلسي ( ت658هـ/1260م)
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One of them one of the important books due to its containing valuable information written by the author. Information include the life of the Messenger (Peace be upon him)

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Publication Date
Fri Jun 30 2017
Journal Name
Journal Of Madenat Alelem University College
دراسة خلايا البشرة والمعقدات الثغرية للسيقان والكساء السطحي لبعض المراتب من عائلة عرف الديك Juss. Amaranthaceae في العراق
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Gompharena globosa L., Irisene herbistii Hook. ex Lindl. The results of this study showed that the anatomical characters of the stems epidermis and the indumentum covering different parts of the plant have an important anatomical characters such as the cell wall shape of ordinary epidermal cells also the shape and type of stomata, their presence in some taxa and abscent in others. The hairs also differentiated by their shapes and them types, either they glandular or eglandular also they are different in distribution between the different taxa or in the some taxon.

Publication Date
Tue Sep 27 2022
Journal Name
Arab Science Heritage Journal
الحركة العلمية في المغرب الاسلامي من خلال كتاب معجم البلدان لياقوت الحموي ( ت 626هـ / 1229م) العلوم الشرعية انموذجا
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    The Dictionary of Countries by Yaqut al-Hamawi is one of the most important sources that researchers rely on in everything related to geography in knowing the names of places and countries, and the important historical information it contains about different cities and countries

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Publication Date
Fri Jun 30 2023
Journal Name
Modern Sport
اثر تمرينات خاصة بأستخدام جهاز المدافع الضوئي المصمم في تنمية بعض القدرات البدنية والاداء المهاري المركب لدى لاعبي كرة اليد
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اتجهت دول العالم الى تسخير جميع الإمكانيات والخبرات والعلوم من اجل الوصول الى مستويات متقدمة في الرياضات المختلفة ويهدف التدريب الرياضي إلى إعداد اللاعبين إعدادا جيدا تكمن مشكلة البحث من خلال خبرة الباحثتان الميدانية ومتابعة تدريبات لاعبي المدرسة التخصصية كرة اليد فقد لوحظ هناك ضعف واضح في الأداء المهاري ولابد من تطوير أوجه الضعف لتحقيق مستوى انجاز افضل . ويهدف البحث اعداد تمرينات خاصة بأستخدام جهاز ا

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Publication Date
Fri Jan 01 2021
Journal Name
الرك للفلسفة واللسانيات والعلوم االجتماعية
فاعلية المواقع الالكترونية للصحف العراقية في تعزيز القيم الايجابية لدى المجتمع ( دراسة مسحية لعينة من جمهور مدينة بغداد )
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اصبحت وسائل الاعلام في ظل المتغيرات الجديدة قادرة على صياغة وعي وثقافة وهوية الشعوب الى حد كبير في المجتمعات المعاصرة , وذلك نظرا لما تتمتع به من اليات مختصة في التأثير والمتمثلة عموما في التكرار المتنوع للرسالة الاعلامية وقدرة الخطاب الاعلامي في معالجة القضايا المختلفة فضلا عن تقديم المعلومات وغزارتها وشرحها المستفيض , وقد بات من الواضح جدا مدى التأثيرات الكبيرة التي من الممكن ان يحدثها تعرض الافراد للمواق

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Publication Date
Mon Mar 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
تصميم نظام مقترح لتخصيص مهام العمل لمحطات العمل وباعتماد الطرق الاجتهادية دراسة حال في الشركة العامة للصناعات الكهربائية
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This research work dealt with the problem of layout the production line of engine of fan roof at the General Company for Electrical Industries (GCEI). It was observed that the assembly line of engine was unstable and subject to severe fluctuations. In addition the execution of tasks at some stations was observed to be very fast while at other stations was slow. This phenomenon resulted into bottlenecks between workstations, idle time, and work in process. The system design was used to assign tasks to work stations according to different heuristics (Ranked Positional weight techniques, longest Task Time, Most following tasks, Shortest tasks time, Least number of following task).

The study revealed that th

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Publication Date
Sat Jan 01 2011
Journal Name
مجلة جامعة دمشق للعلوم التربوية والنفسية
طبيعة العلاقة الارتباطية بين التعاطف والسلوك العدوانيدراسة نيدانية لدى عينة من طلبة المرحلة المتوسطة في مدارس بغداد الرسمية
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استهدفت الدراسة الحالية تحديد طبيعة العلاقة الارتباطية بين التعاطف والسلوك العدواني لدى عينة من طلبة المرحلة المتوسطة. تكونت العينة من طلبة الصف الأول المتوسط بغداد/ تربية الرصافة الثانية من كلا الجنسين، شملت 218 طالباً وطالبة، وطبق مقياس التعاطف، ومقياس السلوك العدواني. وبعد معالجة البيانات، أظهرت النتائج تمتع طلبة الصف الأول المتوسط بالنزعة أو الميل للتعاطف، وتبين أن الإناث أكثر تعاطفاً من الذكور، ومستوى

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Publication Date
Wed Jan 01 2014
Journal Name
Journal Of The College Of Basic Education
اسباب الضعف الاملائي لدى طلبة كلية الادارة والاقتصاد في جامعة بغداد وطرائق معالجتها من وجهة نظر التدريسيين والطلبة
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