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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
Tue Jan 02 2018
Journal Name
Journal Of Educational And Psychological Researches
Teaching techniques due to the Brain-based learning theory among math teachers
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The purpose of the study is to identify the teaching techniques that mathematics' teachers use due to the Brain-based learning theory. The sample is composed of (90) teacher: (50) male, (40) female. The results have shown no significant differences between male and female responses' mean. Additionally, through the observation of author, he found a lack of using Brain-based learning techniques. Thus, the researcher recommend that it is necessary to involve teachers in remedial courses to enhance their ability to create a classroom that raise up brain-based learning skills.  

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Publication Date
Fri Jun 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
جدلية التنظرية في الذاكرة المنظمة بين متاهة النماذج الصناعية وواقعيةالنموذج الهجين
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جدلية التنظرية في الذاكرة المنظمة بين متاهة النماذج الصناعية وواقعيةالنموذج الهجين

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Publication Date
Tue Sep 27 2022
Journal Name
Arab Science Heritage Journal
مفردات قرآنية في معلقة الحارث بن حلّزة اليشكري دراسة صرفية دلالية
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Due to the importance of the word and because it is the basic building block from which speech is formed, it has become the subject of the attention of many scholars, ancient and modern, especially the Qur’anic vocabulary, which scholars dealt with in various branches of the Arabic language

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Publication Date
Sun Dec 27 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تفعيل دور وزارة التخطيط في تقييم الجدوى الفنية والاقتصادية للمشاريع المقترحة
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The success of any work requires the development of prior plans for the success of this work as well as providing the necessary sources of funds for the implementation of those plans, where the start of the research problem of delayed sending project proposals to the Ministry of Planning to do its job oversight in checking the technical and economic of those projects feasibility studies, has sought the researcher to the statement of need activating the role of the Ministry of planning in the study of projects before they are implemented and the trade-offs between important projects and projects the most important as they related to the usefulness of the community as well as the economic feasibility evaluation of them in terms of providin

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
الحیوانات والطیور والحشرات والزواحف في كتاب الفندیداد (احد كتب الافستا الزردشتیة)
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The book of Alphendidad is considered as an important part of the holy book of
Avesta in the Zoroastrian religion. It is a religious and urbanization book that consists of a
number of chapters dealing with the creation. The book includes 22 chapters, mostly edited
as a dialogue between Ahuaramzda the god of goodness and his prophet Zoroaster. The
biggest chapter deals with the rules of purification of vices of the devil and dismissing it of
the places around, hence it is the book of law of Zoroastrian about the important animals,
birds , insects, and reptiles and their categorization according to their creation; creatures of
the spirit of goodness and creatures of the spirit of evilness.
Some of these creatures ar

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Publication Date
Tue Jul 02 2024
Journal Name
مجلة الأستاذ للعلوم الإنسانية والإجتماعية
بنية الزمن في رواية ( ما بعد الجحيم ) للدكتور حسين سرمك حسن .
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يعد الزمان عنصراً جمالياً مساهماً له القدرة على خلق المعنى والدلالة ، ومشاركاً في الاستراتيجية الحكائية إذ ينتقل من مجرد عنصر حكائي إلى محرض للمتلقي فهو زمان الإنسان الداخلي .

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Publication Date
Mon Jul 22 2019
Journal Name
Arab Science Heritage Journal
الجوانب الإنسانية في حياة الرسول الكريم محمد )صلى الله عليه وسلم(
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نجدّ القرآن الكريم والحديث النبوي الشري يقدمان أر ى ميامين لمقيم الداعية
إلى إ امة مجتمع متماسك البنيان

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Publication Date
Sun Jun 30 2019
Journal Name
Journal Of The College Of Education For Women
The poetry of the sensory image of Ibn Dannir al-Musli poems (B627 H.)
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تُعبّرُ الصُّورةُ الحسَّيةُ في شعرِ ابن دُنَينير الموصليِّ([i]) في بنيتها عن تجربةِ الشاعرِ الوجدانيةِ والذهنيةِ, وأفكارهِ ومشاعرِهِ؛ فيصوغُ بها مَفهومًا جديدًا للواقعِ الماديِّ والمعنويِّ، الذي يتسمُ بالوضوحِ أولاً، وبالقرْبِ من الذهنِ ثانيًا، للربْطِ بين الحواسِّ الإنسانيةِ والمعاني الذهنيةِ، لِتُقَدِّمَ الصُّورةُ الحسيَّةُ إلى ((المتلقي صُورًا مرئيةً، يُعادُ تشكيلُها سياق

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
المتغیرات الجدیدة في سیاسة روسیا الاتحادیة تجاه منطقتي آسیا الوسطى والقوقاز
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Federal Russia remains the central player in the space of post-Soviet Union,
particularly in the regions of Middle Asia and the Caucasus , which set standard for
the local transformations of the two regions.
The Russian concern continued about the shift of power in the
world, as long as Russia is concerned with limiting the action of the United States
in the area in which Russia sees as vital area to its national interests. Russia's
nationalists play a main role in reviving Russia's influence in Middle Asia as a vital
area and the natural ally of Russia, but without resorting to the old ways of using
the threat of military force.
The idea of the return of Russia as a superpower in the global arena in
Middle

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Publication Date
Sat Jun 01 2013
Journal Name
Journal Of The College Of Languages (jcl)
دوگانه ای متضاد ( خیر ضد شر ) در شعر فارسی ( بر رسی انتقادی وتحلیلی )
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The conflicting duality of goodness and evil has a psychological effect on the life of humans, the nature of human beings is originally goodness whereas the tendency of evil flows from the society, therefore the first who found a meaning of evil on earth is kabeel when he quarreled fiercly with his brother who carried in himself all the meanings of goodness and toierance.

 

    In this paper of mine we find that Robaayat Al khayam carries a poetic content of a special meaning in that every expression reflects semantic relationship (the good played a part in the formation lies with and the evil) of which its foundation lies with the human personality (soul), and he (the poet) a scribes it to matters of

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