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alkej-347
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
Thu Dec 13 2018
Journal Name
Arab Science Heritage Journal
ال أل العاقولي ودورهم العلمي في الحضارة العربية الإسلامية
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The research includes a bout IL- IQulle , and their role in scientific of the Islamic – Arabic civilization , for Dr. Khlood M.Namma the proff in the collage of education for woman , Baghdad university , History department .

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Publication Date
Sun Apr 01 2012
Journal Name
Journal Of Educational And Psychological Researches
حقوق الطفل في ظل الأزمات المجتمعية /الطفل العراقي انموذجا
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Rights of child in the community crisis Iraqi child model The study aimed to identify the types of violation against children in the Iraqi crisis as well as to develop community coping mechanisms to these violations and promote the rights of the child health psychological , social and legal . the first chapter discusses the research problem and its importance and purpose of the research problem and its importance and purpose of the research and the most important terms in the A- Rights of the child ,B- crisis , chapter 2 rights of the child ensure the historical roots , of children’s rights in the holy quran and the sunnah, and legal rights through the twentieth century and the beginnings of century xx, the se through the twentieth cen

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
הריאליזם ביצירותיו של אהרן מגד "דוגמאות נבחרות מיצירותיו"
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הקדמה

             הריאליזם הספרותי במשמעו הכללי מצייג אשר כל מה מציינת בה הספרות מציורים מדוייקים לסביבה ולכן אדם. ויש להתחשב בפרטים המשותפים לחיים היומיומית.

             האסכולה הריאליזטית מצטיינת בזיאנרים אין זוכים בם איזו אסכולה ספרותית אחרת. האסכולה הזאת הופיעה בספרות העברית החדשה כתוצאה להשפעתה של הספרות העברית בס

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Publication Date
Thu Dec 27 2018
Journal Name
Arab Science Heritage Journal
دراسة في ضرائب الارض عند ابي يوسف و الماوردي
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تتراوح ضريبة الارض ما بين 10%من المحصول (الشعير ) و 40 -50 من الخراج 

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Publication Date
Thu Jun 15 2017
Journal Name
مجلة العلوم الاجتماعية
الشفقة بالذات لدى طلبة الجامعة في ضوء بعض المتغيرات
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هدفت الدراسة التعرف على الشفقة بالذات لدى الطلبة فضلا عن التعرف على الفروق في الشفقة بالذات وفق متغيرات : الجنس –التخصص الدراسي – المرحلة الدراسية، تالفت عينة الدراسة من (200) طالب وطالبة موزعين بالتساوي حسب الجنس (ذكور – اناث) والتخصص الدراسي (علمي - انساني) والمرحلة الدراسية ( الاولى - الرابعة )، وبعد تطبيق مقياس الدراسة وتحليل الاجابات احصائيا ، اظهرت النتائج ان الطلبة لديهم شفقة بالذات كما اظهرت النتائج عدم

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Publication Date
Wed Dec 20 2023
Journal Name
Arab Science Heritage Journal
إلرشادات النبوية في إستخدام أواني الطعام والشراب وأثرها الصحي
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The research included the statement of some prophetic
guidelines for preserving food and drink from contamination that
causes diseases, which originate either viruses and microbes, or
insects and vermin spread in the air,

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Publication Date
Sun Dec 23 2018
Journal Name
Arab Science Heritage Journal
التفسير التفسير النبىي للقرآن الكريم وأحره في التفسير بالمأحىر
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The science of exegesis was started by the first teacher, the Holy Prophet, and then further developed in various methods and approaches through history

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Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة بعض المقدّرات الحصينة في دوال التمييز بأستخدام المحاكاة
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The development in manufacturing computers from both (Hardware and Software) sides, make complicated robust estimators became computable and gave us new way of dealing with the data, when classical discriminant methods failed in achieving its optimal properties especially when data contains a percentage of outliers. Thus, the inability to have the minimum probability of misclassification. The research aim to compare robust estimators which are resistant to outlier influence like robust H estimator, robust S estimator and robust MCD estimator, also robustify misclassification probability with showing outlier influence on the percentage of misclassification when using classical methods. ,the other

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Publication Date
Sun Oct 01 2006
Journal Name
Journal Of Educational And Psychological Researches
الكفايات التدريسية اللازمة لمدرسي التربية الإسلامية في المرحلة الإعدادية
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مشكلة البحث :

إن القرآن الكريم هو النور المبين والذكر الحكيم يحتوي على الغاية الأسمى التي تهدف اليها الإنسانية ، فهو روح التربية الإسلامية وهو المنهج القديم الذي تستمد منه فلسفتنا التربوية واتجاهاتها ،                                        (الزوبعي ، 1974: 18)

إن الدين الإسلامي هو نظام الهي

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Publication Date
Thu Oct 01 2015
Journal Name
Al-academy
The Factors influencing to the cognition operation & its Data: وفاء جاسم محمد
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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

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