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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 Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
السلوك القیادي لدى الاطفال الایتام واقرانھم غیر الایتام في المرحلة الابتدائیة
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The family is considered one of the most important social institutions which has a
strong and clear effect on the child in forming his personality through the process
of social upbringing which works on transforming the child from a merely
biological being into an individual who has customs and traditions and the behavior
of the group to which he belongs, and till now there is no social organization or
institution that can do this process not even in partial way like the family
.Therefore depriving the child of his parents leads to depriving him of the normal
chances of growth which relate to his age stage and thus this shortcoming is hard to
treat and based on the preceding the current research aimed at the follo

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Publication Date
Wed Dec 19 2018
Journal Name
Journal Of Planner And Development
التنمية الحضرية للمناطق السكنية غير الرسمية/العشوائية المتدهورة في مدينة بغداد
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Publication Date
Tue Jan 29 2019
Journal Name
Arab Science Heritage Journal
منهج النديم البغدادي في فهرسة دواوين الشعر (حتى نهاية العصر الأموي )
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الحديث عن محمد بن إسحاق النديم حديث عن عالم جليل كان له فضل تصنيف سفر خالد من أسفار المعرفة و العلم و سجل ضم عناوين ما أنتجته الأمة العربية الإسلامية في وقت عزها و مجدها و سطوع كوكبها في سماء الدنيا ، فجاء هذا الكتاب جامعا نافعا في بابه .

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of The College Of Languages (jcl)
Hicri Dede (1877-1952)
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Asil adi Mahmeut olup mashlasi “ Hicrî “ dir . Ihvânî “ zümresine intisabi dolayısiyle “ Dede “ Lakabiyle anılır . Takriben  H. 1297 yılında Kerkük ‘ te doğmuş . Babası  H. 1305 Senesinde vefat eden Molla Ali Efendi ‘ dir .

       Dedesi Nazîrî dede ise zamanmin ileri gelen şâirlerinden olup kayser adli bir oğludur .  (1)

        Diğer bir kaynağa gore “ Hicrî  Dede H. 1295 yılında Kerkük ‘te doğamuştur . Tanınmış şâir Nazîrî Dede ‘ nin torunudur . Babası Molla Ali Efendidir” . (2)

      

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Publication Date
Mon Jun 15 2020
Journal Name
Al-adab Journal
تفاعلية الجمهور مع التطبيقات الإعلانية في الفضائيات عبر أجهزة الهاتف المحمول
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يهدف البحث إلى تحقيق عدد من الأهداف: الكشف عن مدى تفاعلية الجمهور إزاء استخدام التطبيقات الإعلانية في الفضائيات عبر أجهزة الهاتف المحمول. التعرف على تفضيلات الجمهور بين التطبيقات. الوقوف على أهم الموضوعات التي يفضل الجمهور التفاعل معها في التطبيقات الإعلانية. الكشف عن أبرز المعوقات التي تواجه مستخدمي التطبيقات الإعلانية في الفضائيات عبر الهاتف المحمول. الوقوف على مدى مساهمة التطبيقات الإعلانية في الفضائي

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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
Tue Aug 29 2023
Journal Name
حوليات اداب عين شمس
مقارنات اشتقاقية بين العبرية و العربية والارامية في عمل سعديا جاؤون
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Publication Date
Thu Jan 02 2020
Journal Name
Journal Of The College Of Languages (jcl)
Some of the Grammatical Rules of Writing: Zu einigen grammatischen Erscheinungen im Schreiben
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    Language contains various kinds of grammatical rules that are used to express thoughts and feelings. The present paper studies some of the German language grammatical rules as being the most important basics needed to master and develop the art of writing for the German language learners. Writing is one of the productive language learning skills that transform thoughts into a written form. Hence, constant exercising on the use of the language to master the grammatical rules enables German language learners to develop their creative writing skills.

     The present study discusses the importance of grammatical exercises in developing the language learning abilities. The study provides a gener

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Publication Date
Thu Aug 01 2024
Journal Name
مجلة كامبريدج للبحوث العلمية
الحماية الدولية لحقوق المرأة في ظل الاتفاقيات الدولية (الإتجار بالنساء إنموذجاً)
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تعد ظاهرة الإتجار بالنساء جريمة من الجرائم ضد الأنسانية لما تنطوي على عدوان صريح وواضح على القيم الأنسانية والجماعات البشرية اذ تجعل من النساء سلعة رخيصة ومحلا للعرض والطلب، يمكن تداولها واستغلالها بالوسائل كافة غير المشروعة، فعلى سبيل المثال ان الاتجار بالنساء والأطفال لأغراض الدعارة والاستغلال الجنسي وبيع الأعضاء البشرية والزواج القسري والاستغلال السيء للمهاجرين بصفة غير شرعية، كلها تعد جانباً من جوان

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Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
دراسة أحصائية حول تقدير المساحة المزروعة لمحصول الشلب في محافظة النجف
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The objective of the research is to find the best method to estimate rice crop through out evaluating the applied methods of stratified random sampling .By using different sorts of sampling estimators, a comparison was held among the variances of the mean for simple random sampling, stratified random sampling(var()) and separate regression estimator. The results indicate that the separate regression estimator give best estimations. The approximate cum.f4/5 method was used to determine the optimum stratum boundaries, new strata was put and then var () was calculated .In comparison with strata used nowadays in central statistical organization, the new strata led to obvious decrease in the variance. The stratified mean wa

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