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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
Sat Dec 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
استعمال أنموذج (Altman) للإفلاس دالة لقياس الأداء دراسة تطبيقية في بعض الشركات المساهمة الخاصة العراقية
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Performance measures are a central component of management control system, making good planning and control decisions requires information about how different subunits of organizations have performed. To be effective, performance measures (both financial and nonfinancial) must also motivate managers and employees at all levels of organization to strive to achieve organization goals.

To give aclear picture about performance must be used compound measure, that was best than single measure.

Altman model can be used as a compound performance measure that measures the performance by tied a sum of variables, due to make weight for every variable to reach for performance.

 

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
استخدام ادوات التحليل المالي كمؤشرات لتحديد واحتساب ضريبة الدخل: دراسة تطبيقية في الهيئة العامة للضرائب
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A financial analysis tool such as financial rations concentrates on explanation of financial statement and using them in the evaluation of company profiles and fixing taxable profits, by analyzing final calculation, explaining their results and studying relationships between a group of financial lists 'elements in a specific period and the trend of their relationships in percentage from so, financial analysis is considered on important instrument for tax analytical test procedures through studying and evaluating financial data in order to get proper information which is needed to make sure of credibility and reliability of statements submitted by the taxpayer and the satisfaction of the tax analyzer in the credibility of these statements

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Publication Date
Mon Mar 01 1999
Journal Name
مجلة الاستاذ للعلوم الانسانية والاجتماعية
اخلاقيات مهنة العاملين في المكتبات المركزية الجامعة بغداد والمستنصرية والتكنولوجية من وجهه نظر المستفيدين منها.
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يهدف البحث إلى معرفة ما هيه اخلاقيات مهنة العاملين في المكتبات وتحديث متطلباتهم الضرورية من المهنة لكي يسمو بأخلاقياتها ، وهل هذه الاخلاقيات متوافرة في العاملين في مكتباتنا الجامعية ضمن حدود الدراسة ؟ ومن ادوات جمع البيانات : استمارة بالاخلاقيات وزعت على مجموعة من الاساتذة و استبانة وزعت على من المكتبات الجامعية . وكان مجتمع الدراسة العاملون في المكتبات المركزية الأولى والثانية لجامعة بغداد والمكتبة المرك

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Publication Date
Mon Nov 12 2018
Journal Name
Arab Science Heritage Journal
الحجاج الحِـجاج في الشـعر الأنـدلـسي_ عـصر الطوائـف - (حجاجية الورد والنرجس لأبي بكر بن القوطية* أنموذجاً)
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Argumentation in the era of Andalusia poetry Denominate on the orbital roses and narcissus to Abu Bakr bin Gothic model research deals with the subject of Argumentation and employment in Andalusia Poetry has been studied in two sections display in the first reasons of self- Argumentation included human relationships

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Publication Date
Wed Nov 12 2025
Journal Name
Journal Of Physical Education
Standard Levels of Modern Administration for the Iraqi Central Olympic Committee's Olympic Federations
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The problem of the research lies in the lack of standard levels for modern administration as a guide for evaluating weaknesses and strengths as well as finding solutions. The aim of the research lies in identifying standard levels for modern administration in Iraqi central Olympic committee and international federations. The subjects were (24) Olympic committee' federations. All procedures were standardized to fit our modern administration work. The data was collected and treated using proper statistical operations. The researcher concluded standard levels for modern administration in international federation of the Iraqi Olympic committee, in addition to that he concluded that most administrations levels ranged within four levels (good, fa

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Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Planner And Development
نظام الفعالية السكنية ومستوى الضوضاء الحالة الدراسية:- منطقة سكنية في مدينة اربيل/ منطقة راستي الجديدة
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Publication Date
Wed Jun 01 2011
Journal Name
Political Sciences Journal
أسس بناء الجهاز الاداري الكفء : قراءة في عهد الامام علي بن ابي طالب لمالك الأشتر
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أسس بناء الجهاز الاداري الكفء : قراءة في عهد الامام علي بن ابي طالب لمالك الأشتر

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
اختبار العلاقة بين التدفقات النقدية والعوائد المتحققة للاسهم: دراسة تطبيقية في سوق العراق للاوراق المالية
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غالبا ما يؤكد موضوع تحليل البيانات المالية على اختبار عناصر التدفق النقدي لغرض النتبؤ بعوائد الاسهم بالمستقبل ، فضلا عن ان المستثمرين دائما ما يبحثون عن زيادة عوائد الاسهم، وان مثل هذا النوع من التحليل يمكن استخدامه لطبيعة المعلومات المحتواة في عناصر التدفق النقدي ، والدرجة التي على اساسها تنعكس مثل هذه المعلومات المالية في اسعار الاسهم من خلال تقويم القيم السوقية للأوراق المالية فتؤدي إلى تغيير قرارات م

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Publication Date
Wed Jul 01 2015
Journal Name
Journal Of Educational And Psychological Researches
The impact of education differentiated strategy to modify the alternative conceptions Geographical concepts when students First grade average
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The aim of this study was to know ( the impact of education differentiated strategy to modify the alternative developments of geographical concepts when students first grade average) .
      To achieve the goal of this study , researcher relied on the experimental design of a partial set , the design is ( the experimental group with a control group of post-test )
.

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Publication Date
Sun Jun 18 2023
Journal Name
Arab Science Heritage Journal
التعايش السلمي في الاسلام بين التنظير والتطبيق عهد الامام علي (عليه السلام) للاشتر النخعي / انموذجا
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     Peaceful coexistence is not seen as a new topic of secretions of modern civilization, a requirement to solve the problems of our era or one of the indications of urgent immediate needs, rather, tolerance is considered basis for building a state. Therefore, we can touch on the principles and basics of tolerance in the Holy Qur’an, the speeches of the Messenger (may God bless him and grant him peace) and his hadiths, and the principle of brotherhood that he established

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