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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
Wed Oct 11 2023
Journal Name
Journal Of Educational And Psychological Researches
The Degree to which Arabic Language Teachers at the Secondary Stage Possess the Teaching Competencies Necessary to Develop the Literary Appreciation Skills of Their Students from the Point of View of Educational Leaders in Bisha Governorate
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This study aims to identify the degree of Arabic language teachers at the secondary stage possessing the teaching competencies necessary to develop the skills of literary savor among their students from the perception of educational leaders in Bisha Province. To achieve the objectives of the study, the descriptive approach was used by adopting a comprehensive survey method. The study sample consisted of (48) school principals and Arabic language supervisors in Bisha Province who supervise the teaching of Arabic language at the secondary level in Bisha Province. The necessary data was collected using a questionnaire. The results of the study revealed that the evaluation of the study sample for the degree to which Arabic language teachers

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Publication Date
Sun Jan 17 2021
Journal Name
Arab Science Heritage Journal
المبادرة في عهد الامام علي بن ابي طالب (عليه السلام )
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    Thank Allah and prayers on the Prophet Mohammed the man of truth and honest (PBUH).

The initiations in the role of Imam Ali (PBUH) is considered among the important initiations in Islamic thinking .It is considered the way to invest the conditions that the individual in the light of it can reach to make gains and achievements

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Publication Date
Mon Jan 23 2023
Journal Name
Arab Science Heritage Journal
الجوانب النفسية في تفسير الأمثل للشيخ الشيرازي ) آيات التحدي إنموذجاً(
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The wisdom of the Creator ensures the call of every prophet with a miracle that would be something beyond what is familiar from the customs

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Publication Date
Thu Dec 31 2020
Journal Name
College Of Islamic Sciences
Mada alfay fi taqrir lays kamithlih shay Sheikh Abrahim al kurde
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The message of the Kurdish tag tagged with(Mada alfay fi taqrir lays  kamithlih shay) one of his most prominent scientific messages in the door of faith, especially in the matter of the unification of the divine self and its distancing from all analogies and representations  and the importance of this message historically, due to its documentation of a stage in the development of Islamic speech thought, where the logical method was taken over the minds of the intellectuals of Islam, including the kurani, whether it is in understanding the quranic and modern meaning or as a way of convincing me towards the opponent.

The Kurd was able to use logical concepts to marginalize the difference between grammarians and interprete

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Publication Date
Wed Dec 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
إنشاء جائزة عربية للجودة في قطاع التعليم العالي: رؤيــة عراقيــة
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  IF we called twentieth century, the century of productivity and information revolution, the suitable address for twenty-first century is (( The quality century )) .

The research aims to initiate Arabic prize for quality to apply concepts and strategies of total quality management at Higher education sector, which is a vital sector and it may be the most importance sector because it provide efficient human manpower working at all other sectors.

The suggested prize take in consideration the specialty of this sector, and when we apply perspectives of this prize this will promote Arabic universities performance as well as the quality of graduates.

The importance of this research due to the necessity of this pri

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Publication Date
Thu Jan 01 2015
Journal Name
دار الضياء للطباعة والتصميم
SPSS النظرية والتطبيق في Exploratory Factor Analysis التحليل العاملي الاستكشافي
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يعد التحليل العاملي Factor Analysis أحد الأساليب الإحصائية المهمة والتي يصعب تنفيذها يدويا ً أو بالألات الحاسبة الصغيرة لذا لاقى الباحثين صعوبة في إستخدامه في البداية بل كان من المستحيل القيام به ، لذا فالمؤلف قد تناول التحيلي العاملي الاستكشافي لكونه إسلوب إحصائي يستخدم في تحليل البيانات ويتطلب شروطا ً لأستخدامه ودقة في مراعاة هذه الشروط ويتطلب أيضا ً معايير يجب أن يتأكد الباحث من توافرها في البيانات وهذا ما تم ت

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Publication Date
Tue Jan 01 2019
Journal Name
حوليات اداب عين شمس
فعل الامر من صيغة N المبني للمجهول في اللغة الاكدية
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يتناول هذا البحث موضوع (( فعل الامر في صيغة المبني للمجهول في اللغة الاكدية )) وهو يتعلق بقواعد اللغة الاكدية , وقد تضمن هذا البحث مقدمة وشقين : صيغة المبني للمجهول وفعل الامر. اما ما يخص المقدمة فقد شملت تعريف الفعل وانقساماته حسب قوة احرفه , الجذر , المعنى , والفاعل , كما تضمنت المقدمة أيضا الحديث عن الصيغ الفعلية الرئيسة الأربعة التي يتألف الفعل الاكدي منها إضافة الى الصيغ الثانوية التي تتضمنها الصيغ الرئيسة . و

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Publication Date
Thu Dec 01 2022
Journal Name
مجلة العلوم السياسية
جدلية العلاقة بين الديمقراطية والحرية في الفكر السياسي لكارل بوبر
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تتفق الدراسات الحديثة على ان النظام الديمقراطي في بلد ما لايمكن ان يقام الا في ظل جو تسوده الحرية السياسية والدينية، الا ان مصطلح الديمقراطية ومصطلح الحرية وضُعا في دائرة جدلية، لان مفهومهما بقي متعدداً ومختلفا فيه. يعد كارل بوبر من ابرز الفلاسفة في الفكر السياسي الغربي المعاصر المدافعين عن الديمقراطية بوصفها النقيض للديكتاتورية، إذ حدد وظيفتها بقدرتها على كبح جماح النخبة الحاكمة واخضاعها للقانون لمنع نزو

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Publication Date
Mon Dec 26 2022
Journal Name
Arab Science Heritage Journal
المصاحبة اللفظية بين الصفة والموصوف في خطب الرسول(  ) دراسة دلالية
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There are words that are described in certain words that are not described in other words, so the relationship between two words that accompany a habit is strengthened, which leads to the emergence of a conjunction or an idiomatic expression. It did not exist before their association together,

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Publication Date
Wed Jun 07 2023
Journal Name
Journal Of Educational And Psychological Researches
Selective Visual Attention among Students of Colleges of Education At The University Of Mosul
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The research aims to identify the level of selective visual attention among students of the faculties of education at the University of Mosul. To achieve the goal of the research, the researchers chose a stratified random sample of students from the faculties of education at the University of Mosul for the academic year (2020-2021). The sample size was (652) students from the scientific and humanitarian specializations, the second and fourth stages. The researchers developed a test of multiple-choice to measure the selective visual attention, which consisted of (42) items. The results revealed that the students of the faculties of education for human sciences have an appropriate level of selective visual attention. There are statisticall

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