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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 Jun 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
دور ومسؤولية مراقبي الحسابات في العراق تجاه الأفصاح الألكتروني للقوائم المالية
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This research aims at shedding light on the electronic disclosure of the financial information under the condition of the development of this kind of disclosure all over the world , and its effect  on the job of auditing and accounting . It also aims to show the extent to which the observers of accounts are aware of their duties towards this kind of disclosure and to test the effect of some environment factors on the level of this awareness.

To achieve the aims of the research has been divided in to four parts. The first one deals with mathadolge of the research. The second parts is devoted to the theoretical aspect of the research referring to the notion of electronical, disclosure its features and effect on the auditing jo

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Publication Date
Tue Jan 01 2008
Journal Name
رسالة ماجستير
دراسة مقارنة بين الشكلين الحلزوني والمكور في بكتريا ال Helicobacter pylori
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Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Planner And Development
(الاستخدامات الحضرية للمياه في المدن العراقية حالة الدراسة (مدن الفرات الأوسط
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Publication Date
Fri Jun 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
Le rire amer du point de vue énonciatif dans " la guerre de Troie n' aura pas lieu" de Jean Giraudoux
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Si le rire est censé être le propre de l'homme, il n'en est pas pour autant toujours signe d'intelligence. Qui n'a  jamais eu honte d'avoir ri àune blague idiote ou méchante?

     Il y a plusieurs  façons  de rire , ce qui fait que ce qui est  comique  pour les uns ne l'est pas pour les autres et que le comique réside moins dans l'objet ( situation, blague..) que dans le point de vue et dans l'interprétation que nous en ferons. " Le rire .. contient toutes les mélancolies humaines ([1]) ".

([1] )

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Publication Date
Sun May 10 2015
Journal Name
Al-academy
Artistic trends to the formation of postmodern: إيهاب احمد عبد الرضا
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This research includes interested in studying art contemporary, by studying the experiences of sculpture for the formation of post-modernism, assuming the existence of trends in public art can be classified, in spite of the multiplicity of styles and methods of work since the second half of the twentieth century to the present day, and this shenanigans knowledge on how to the Technical that is the art is not restricted, It is art refuses laws and fixed values and traditional styles, and always aspires to diversity and innovation.Search contains three chapters and an introduction containing information about the research problem and the importance of research and the goal of the research, the goal of research is: Detection of artistic tre

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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
Sun Jul 01 2012
Journal Name
Journal Of Educational And Psychological Researches
الاشكال المفضلة لدى اطفال الرياض ونسبة توظيفها في تصاميم اثاث الرياض
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The research explores the shapes preferred by children and the extent to which it can be utilized on the experimental kindergarten at the Woman’s School of Education. To achieve the goal, the researcher has displayed pictures that have been chosen from within the research boundaries which represent four categories: Geometrical shapes which included (squares, rectangles, triangles, and circles), agricultural shapes which included (apples, oranges, bananas, and grapes), motion pictures shapes (cartoon characters) which included (Jerry the mouse, Twitty the bird, Bugs Bunny the rabbit, and Winnie the pooh), and animal shapes which included (dogs, fishes, frogs, and horses) to the sample children of (60) child (boys and girls) that

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Publication Date
Thu Oct 01 2015
Journal Name
Al-academy
the diversity of the extraction methods of calligraphic straps at Baghdad's mosques: جواد كاظم حداوي
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The art of calligraphy is regarded as one of the tremendous and distinct products in the history of Islamic arts through the unparalleled high ranks it reached to, until it gained Islam's indication and became a symbol for it, in terms of its function linked to the calligraphy of the holy Qur'anic texts, where this merit formed a strong impulse in seeking its development, the emergence of the calligraphic constructs, including the calligraphic straps, is one of this continual seeking products, and an advanced stage at the level of technical and expressive development, and also one of the natural results generated by the development of fonts and the increase of their employing methods through what they recorded at the level of formal char

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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 إامة مجتمع متماسك البنيان، وبناء فرد ذي شخصية متزنة، لا تعر التردد

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Publication Date
Tue Jan 01 2008
Journal Name
Journal Of Educational And Psychological Researches
البواعث النفسية في رسم لوحة التشبيه - عند شعراء ما قبل الإسلام -
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        مما توصل إليه البحث  :

            إن الدوافع النفسية تنفرد في تجسيد الأحاسيس والمشاعر في نتاج الشاعر , من خلال رؤيته لتلك الحالة , فتسهم في صورة المقارنة في التشبيه , فتبعث في المتلقي حالة التأمل والمقارنة بين الحالتين اللتين تجمع بين مكوناتهما صفة واحدة فتصل إلى حالة التلاحم , ويكون ذلك باعثا لرسم صورة التشبيه ال

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