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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
Fri Jan 01 2010
Journal Name
مجلة العلوم التربوية والنفسية
أثر استراتيجية تعلم الاقران في تصحيح الفهم الخاطئ للمفاهيم الجغرافية لدى طالبات الصف الاول المتوسط
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يرمي هذا البحث الى تعرف اثر استراتيجية تعليم الاقران في تصحيح الفهم الخاطئ للمفاهيم الجغرافية لدى طالبات الصف الاول متوسط

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Publication Date
Mon Jan 01 2018
Journal Name
مجله كليه التربيه للبنات
دراسه الاعلان التلفزيوني وتأثيره في السلوك االاستهالكي لدي عينه من الاطفال بعمر(9-12) سنه
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Publication Date
Sun Sep 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Using Six-Sigma to measure the quality performance of the Department of Statistics-University of Baghdad-Case Study
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Abstract

            This research was to provide a definition of quality, dimensions and concepts, whether traditional or modern concept, as well as review the dimensions of quality in higher education and vision and mission with the overall objectives of the Statistics Department.

         After reviewing quality goals and purposes achieved as well as the mechanisms used to achieve them. and use standard Six-Sigma as one of the methodologies used in quality with the historical roots of using this methodology and methods applied and their definitions t

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Publication Date
Sun Apr 01 2012
Journal Name
Journal Of Educational And Psychological Researches
أثر أنموذج وودز في تصحيح المفاهيم الجغرافية ذات الفهم الخاطئ لدى طلاب الصف الأول المتوسط
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The present study aims at knowing the effect of Woods' model in correcting the geographical missUnderstanding for first stage students. In order to realize the objective of this study, the researcher used an experimental design with partial adjustment which is experimental group with another control group. The research is confined to the first four chapters of the boon of the principles of geography to be studied for the first stage in the academic year (2010/2011) in Iraq. The researcher chooses purposely the chose a staple form the first stage in Hay Al-Jama'a School for boys, in order to apply the experiment. The total number of the sample was (60) students who were distributed randomly as (30)per group. The researcher matched two gro

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Publication Date
Wed Oct 24 2018
Journal Name
Journal Of Planner And Development
الآليات التخطيطية لتوفير خدمات البنى التحتية في قطاع الإسكان (مدينة الكاظمية المقدسة إنموذجاﹰ )- محلة 413،405،407
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Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
بعض الاضطرابات السلوكية والانفعالية والانفعالية وعلاقتها بالاستعمال المفرط للألعاب الالكترونية لدى التلاميذ في المرحلة الابتدائي
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سعى البحث الحالي الى التعرف على بعض الاضطرابات السلوكية والانفعالية وعلاقتها بالاستعمال المفرط للالعاب الالكترونية لدى تلاميذ المرحلة الابتدائية, إذ يواجه التلاميذ مشكلات سلوكية عديدة ،تظهر من خلال تعاملهم مع اقرانهم في البيت او في المدرسة والتي قد تتطور عند بعضهم وتتحول الى اضطرابات نفسية،مما يؤدي بهم الى ضعف التعلم وسوء التوافق في حياتهم المدرسية ويصبحون عُرضة للا صابة بالامراض النفسية ،إذا لم يتم تشخ

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Publication Date
Mon Jan 02 2017
Journal Name
Journal Of Educational And Psychological Researches
تقويم جودة مهارات التدريس لدى مدرسي الرياضيات في المرحلة الإعدادية الفرع العلمي من وجهة نظرهم
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   Research aims at evaluating the quality of the teaching skills of math teachers in junior high / scientific branch  from their point of view.

The researchers prepared for this purpose a quality of teaching skills standards questionnaire, It consisted of 72 items distributed on four axis, The research sample was 200 teachers The researchers used statistical methods: the arithmetic mean, standard deviation, variance test, test Shiva  , The results showed a statistically significance difference Attributed to the qualification  variable  in the second  axis (Planning for teaching topics) And the absence of statistical difference function,

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Publication Date
Wed Nov 14 2018
Journal Name
Arab Science Heritage Journal
التحديات التحديات المعاصرة للثقافة الإسلامية دراسة في الصورة النمطية المتبادلة للسلام وللحرب بين الإسلام والغرب
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Islamic Culture face many challenges Such as، Secularism، westrenism، globalism and Colonialism under current attempts For western States and united states of America to dominate on world and Confront all her Opponent Polaris it be clear when U. S. A. Occupied Afghanistan and Iraq and Threatened many Arabic and Islamic States

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Publication Date
Fri Jan 01 2016
Journal Name
مجلة جامعة كربالء العلمية
دراسة شكليائية ونسجية للكلية في الساحف )أبو بريص( وزغة خشنة الحراشف Cyrtopodion scabrum (Heyden, 1827)
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Publication Date
Sun Feb 03 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Effect of The Mental image Building Dimensions for The Company to Aattract Attention of Iraqi Consumers for local Products: Exploratory Study
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The survey showed sample opinions of officials in the general company for vegetable oils industry, and the statement of the order of the effect of these dimensions depending on the degree of importance, the questionnaire was used as a key tool in collecting data and information of the sample consisted of 30 officials, arithmetic mean, standard deviation, percentages, Spearman correlation coefficient and the global statistical analysis as a statistical methods that based on statistical program (SPSS), The researcher came to several conclusions, most important that there is high agreement by the respondents of the importance of the dimensions of building a mental picture of the company and to attract the consumer's attention, Also research

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