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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
Tue Apr 01 2008
Journal Name
Journal Of Educational And Psychological Researches
أثر أستعمال الأسئلة التحضيرية في أكتساب طالبات الصف الرابع العام للمفاهيم التاريخية
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        يمر عالمنا المعاصر اليوم بمرحلة من التطور والتغيير السريعين لم يسبق له أن مر بهما فـي تاريخ البشرية ، ويشمل مظاهر الحياة  الأنسانية  والأقتصادية والعلمية والتربويـة والنفسية وغير ذلك . وتختلف سرعة هذا التغيير من مجتمع الـى مجتمع آخر , وأدى هذا الى تراكم كميات كبيرة من المعلومات .

         لقد أكد الكثير مـن التربويين أن التطور التكنولوجي فـي ال

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
المحاسبة الإدارية الشاملة حقيقة التطور في ظل التقدم العلمي ومفهوم الذكاء الاصطناعي
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خضعت المحاسبة الإدارية إلى هيمنة المحاسبة المالية عليها اثر ظهور القوائم المالية المدققة في بدايات القرن الماضي الناتجة من ظهور المنظمات المنظمة للمهنة وما رافق من إلزام الشركات بإعداد التقارير المالية من الحسابات المالية وفقاً للمبادئ المحاسبية المقبولة قبولاً عاماً والتي أثرت في قيمة المعلومات المقدمة من قبل المحاسبة الإدارية مما أدى إلى إن تصبح تلك المعلومات غير ملائمة للاستخدام الإداري وهو ما ا

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
"حركة نیاغارا" في الولایات المتحدة الامریكیة: مقدماتھا ، نشأتھا، ١٩١٠- وعوامل انھیارھا ١٨٩
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The Negro minority in the United States is associated with social injustice,
political deprivation, and economic oppresion. Its members felt that they are
second-class citizens, and that the acceptance of such status will lead to the
continual oppresion of the Whites upon them. As a result, the educated community
adopted a process to put a framework to their opposition to the former's injustice.
This organised framework is exemplified in the "Niagara Movement," which is
regarded as the first national organisation for Negros. The topic of this study is
chosen due to its historical and political significance.
The study consists of an introduction and five sections. The first section
addresses the preliminaries an

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Publication Date
Sun Oct 14 2018
Journal Name
Arab Science Heritage Journal
الاجراءات الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد 1932-1938
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شكلت السيطرة العثمانية على العراق  حقبة تاريخية مهمة ، حيث وضعت فيها ركائز عدد كبير من الأنظمة الأدارية  فغدت  الأساس للتنظيمات  فيما بعد ومنها  الإجراءات الإدارية والقانونية وسبل معالجتها لآزمة الأراضي في بغداد1938-1932.

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Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Visible Enhanced Photodetector Made by Spray Pyrolysis
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Barium–doped TiO2 / n-Si photodetector was fabricated by spray pyrolysis exhibited visible enhancement responsivity profile with peak response at 600 nm flat response between 650 and 900 nm. The quantum efficiency was 30% and specific detectivity was 5x1012 W-1Hz1/2cm at peak response. The GaAlAs laser diode was used to estimate the rise time of the detector.

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Publication Date
Mon Jan 07 2019
Journal Name
Arab Science Heritage Journal
دراسة طبيعة غذاء الحية المائية Natrix tessellata في موسم التكاثر شرق بغداد
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       جمعت 50 حية مائية Natrix tessellata على وجبتين الأولى 25 حية عند فصل الربيع  تحديدا من منتصف آذار الى منتصف نيسان، اما المجموعة الثانية ، 25 حية لفصل الصيف من منتصف حزيران الى منتصف تموز. اذ عزلت الذكور عن الإناث و حللت قطع من لحم الذكر و قطع من

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Publication Date
Sat Mar 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
استخدام بعض الطرائق الاحصائية والتصنيف الشجيري في التصنيف والتنبؤ بإفلاس الشركات مالياً
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تستخدم تقنيات التصنيفِ ًبصورة واسعة جدا في كثير من المجالات التطبيقية. ولاسيما في المجالات الاقتصادية والتحليلات المالية كما في عِلْمِ تحليل الزبونِ التنبؤيِpredictive customer analytics ، الذي يتضمن ذلك  الإمتلاكِ، المقايضة، إحتكار وإحراز الإئتمانِ والجباياتِ. إنّ هدفَ أيّ نموذج تصنيفِ هو أَنْ يُصنّفَ َ المشاهدات   في مجموعتين أَو أكثرِ للوصول الى التنبؤ بنتيجةً ترتبط بكُلّ مشاهدة ومثا

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Publication Date
Sun Apr 03 2011
Journal Name
Journal Of Educational And Psychological Researches
The use of the husband of violence against his wife who is a kindergarten teacher
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Wives generally and working wives especially may encounter in some
families forms of physical or psychological violence through all the
levels or whether it was a psychological intimidation or cursing and
insolence and detracting her human . value and the husband marries
another woman or uses physical abuse against her and beating and
sexual abuse of the wife are also included in this from . it is noticed that
the violent attitude of the husband may take one from or it may change
and alter with time for it might lead to the increase of the possibility of
violence to occur in different ways
The importance of this study comes out from the step that on which in
folds the problem of the use of the husband of vio

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Publication Date
Sat Dec 29 2018
Journal Name
Journal Of Planner And Development
اهمية تطبيق المعايير التخطيطية للفضاءات المفتوحة والخضراء ودورها في التخطيط الافضل للمدن
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Publication Date
Fri Dec 15 2023
Journal Name
Al-academy
Utilising modelling software to convert functional utensils into ceramic art.
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Contemporary art has been widely affected by technology, and ceramics production is no exception. As an ancient art that originates from clay and other humble materials found in the ground, ceramics is considered one of the most adaptable art forms. Once it is realised how flexible ceramics as a material is, it can be easily altered into endless forms and shapes. Therefore, it is vital for ceramics practitioners to find a relationship between this wonderful material and the media of contemporary art, culture and modelling software or technology in general so that they can take their deformable art pieces to a whole new level. Such a relationship is worth investigating. Thus, for the purposes of this research, several ceramic pieces were

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