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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 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
أثر سياسة السجلات المحاسبية المفتوحة كأحد آليات إدارة التكلفة في تحقيق الميزة التنافسية للشركات الصناعية المساهمة العامة الأردنية
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The aim of this research is to study and test the impact of the policy of open-book accounting as one of the cost management mechanisms in achieving the competitive advantage in Jordanian industrial public companies, to achieve the objectives of the study, a field study was conducted by surveying the views of a sample of the accountants of the Jordanian industrial public companies. Hence the arithmetical Means, the Standard Deviations, the Significant Value and the Simple Linear Regression are used to test the research hypotheses and to achieve the research goals. The results of the study showed that there is a statistically significant effect of the policy of open-book accounting as one of the cost management mechanisms in achieving the

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Publication Date
Sun Oct 01 2006
Journal Name
Journal Of Educational And Psychological Researches
الصعوبات التي تواجـه طلبة أقســـــام طرائق تدريس القرآن الكريم والتربية الإســــلامية في مادة طرائق التدريس من وجهة نظرهم
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- مشكلة البحث

تشغل مادة طرائق التدريس مكانة متميزة في عملية التعليم والتعلم لما لها من دور كبير وفاعل في إيصال المادة العلمية إلى الطالب بنجاح .

وقد عزى بعض الباحثين التأخر الذي رافق طرائق تدريس التربية الإسلامية إلى ضعف إعداد المدرسين وتأهيلهم التربوي ولا سيما أن عدد غير قليل منهم من كليات غير تربوية فهم خريجو كليات العلوم الإسلامية والجامعة الإسلامية والإدارة والاقتصاد

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Publication Date
Thu Nov 12 2020
Journal Name
Arab Science Heritage Journal
( مُختَصَرُ الإمام المَيدانيّ في عِلم التَّصريف ) للإمام أبي الفضل أحمد بن محمّد بن إبراهيم الميداني ( ت 518 هـ )
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    The aim of this research is to make a new investigation of a scientific thesis in Arabic Morphology in which an allusion occurred in relation to its real author and its title, there is alot of dropping and flaw when it was first applied due to depending on one written transcript

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Publication Date
Fri Mar 31 2017
Journal Name
Journal Of Engineering
Aerodynamic Characteristics of a Rectangular Wing Using Non-LinearVortex Ring Method
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The aerodynamic characteristics of general three-dimensional rectangular wings are considered using non-linear interaction between two-dimensional viscous-inviscid panel method and vortex ring method. The potential flow of a two-dimensional airfoil by the pioneering Hess & Smith method was used with viscous laminar, transition and turbulent boundary layer to solve flow about complex configuration of airfoils including stalling effect. Viterna method was used to extend the aerodynamic characteristics of the specified airfoil to high angles of attacks. A modified vortex ring method was used to find the circulation values along span wise direction of the wing and then interacted with sectional circulation obtained by Kutta-Joukowsky the

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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
ESTIMATION OF THE OPTIMUM BED THICKNESS OF A FLOWTHROUGH POROUS ELECTRODE (FTPE) WORKING UNDER MASS TRANSFER CONTROL
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In this paper, a theoretical analysis of optimum bed thickness operates under mass transfer control for realizing a high efficiency and reaction conversion of an electrochemical reactor has been made based on flowthrough porous electrode (FTPE) configuration. Many models have been used to represent the optimum bed thickness by taking a look into previous works concerned and collecting all related information, data, and models. The parameters that affect the optimum bed thickness have been visualized and reviewed, and almost all of them have been examined by experimental data from different sources and based on the various models. It has been found that the increase in electrolyte flow rate, concentration, limiting current density, and sp

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Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
الحوكمة المؤسسية المصرفية ومدى توافر دعائمها للوقاية من ألأزمات المالية في المصارف العراقية الخاصة المقيدة بسوق العراق للأوراق المالية
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Growing interest in the subject of corporate governance after the repercussions of financial collapses of some of the leaders of American companies and European, and the consequent crisis of confidence in global financial lists of companies due to weak accounting disclosure and transparency, was quick from many countries and international organizations to adopt the concept in an attempt to improve the situation of companies and promote transparency and prevent further financial crises in the future. Based on this background, the present study aims to shed light on the concept of exercising the powers of governance that has become invitations for adoption in Iraq of great importance, given the increasing role of corporations both restrict

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Publication Date
Tue Feb 02 2021
Journal Name
جامعة واسط مجلة كلية التربية
استعمال الانموذج اللوجستي ثنائي المعلم في بناء وتدريج مقياس الشخصية الافتراضية المتعدد الابعاد لطلبة الجامعة وفقا لنظرية الاستجابة للفقرة
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تهدف الدراسة الحالية الى استعمال الانموذج اللوجستي ثنائي المعلم في تدريج مقياس الشخصية الافتراضية المتعدد الابعاد لطلبة الجامعة وفقا لنظرية الاستجابة للفقرة، والخروج بتعميم لنتائج البحث والوقوف على الاجراءات العلمية المناسبة وتوفير تطبيق عملي علمي صحيح لاعتمادها من قبل الباحثين. وقد اتبعث الباحثة الاسلوب العلمي من خطوات واجراءات في عملية بناء المقياس حيث حدت ابعاد الشخصية الافتراضية المتمثلة بسبع ابعا

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Publication Date
Thu Dec 31 2020
Journal Name
College Of Islamic Sciences
نماذج من التمازج في قصص الأنبياء بين التشريعات السماوية الثلاث : الإسلامية واليهودية والنصرانية: التشريعات السماوية الثلاث: الاسلامية واليهودية والنصرانية
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   يهدف هذا البحث إلى تأصيل الإستدلال بالقاعدة العقائدية، وبيان ضوابطه، وإبراز نماذج من أهم تطبيقاته المعاصرة، وقد أعتمد مناهج من أهمها المنهج الإستقرائي والمنهج المقارن ، وتناول البحث التعريف لقصص النبوة فى الأديان السماوية ، وعرض بعض الدراسات السابقة التى تناولت نفس الموضوع ، ثم تطرق البحث لذكر نماذج من قصص الأنبياء من الديانات السماوية الثلاث ، وتوصل البحث الى أن الأديان السماوية رغم بعض الإختلاف

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Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
مقارنة تأثیر جمع البیانات المختلفة زمنیاً مع نموذج الجاذبیة السلوكي في مدینة بغداد (حالة الدراسة دالة الإعاقة لرحلة العمل)
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As we know the transportation studies regarded as one of a very
important and difficult studies and one of its difficulties created from the
process of data updating therefore the researcher well facing many difficulties
to balancing between the old data on collecting new data.
The research present an opinion which is summarized by: can we use
the old data after we updated and used it as alternatives? Or the researcher
must collect new data to complete their research which indicate to the present
situation and some times they cant complete their studies because of the
security, economic, temporally difficulties.
The research used two kinds of data, the old data which belong to the
period (1998) and new data

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Publication Date
Thu Nov 12 2020
Journal Name
Arab Science Heritage Journal
تحفة الأصحاب ونزهة ذوي الألباب (ما جاء في ذكر المعادن)، احمد بن إبراهيم الحنفي السروجي (ت710هـ/1310م)،"دراسة وتحقيق".
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Manuscript (Tuhfat Al-Ashaba and the Nuzha Al-Kulbab) by Ahmed bin Ibrahim Al-Hanafi Al-Suruji (d.710 AH / 1310 AD), one of the important manuscripts as an encyclopedia characterized by the diversity of its topics

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