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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
Mon Oct 22 2018
Journal Name
Arab Science Heritage Journal
رؤساء رؤساء النصارى في كتاب أخبار بطاركة كرسي المشرق (132- 542هـ/ 749- 1147م) دراسة تأريخية (القسم الأول)
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The research deals with the Presidents of the Christians who called themselves (Ghaltka) in the book titled (orient chirsy patriarchs) that talked about their scientific practical biography adding to) that their completeness on the position of Ghaltka with its decrees and caliphs who were contemporaries to them ,as well as their places, deaths, cemeteries and their accomplishments In accordance with the powers granted to them and also it mentions the situation of The Abbasid caliphate with them and with the sons of their sect .

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of The College Of Languages (jcl)
Problemas en la Traducción de la Fraseología del Español al Árabe en el Texto Literario ( Un Estudio Comparativo desde el Punto de Vista Traductológico)
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Problems in the Translation of Spanish phraseology to Arabic in the Literary Text (A Comparative Study from the Perspective translatological)

 

Abstract

One of the most common problems facing the translator is the identification and subsequent search for correspondences of phraseological units. The importance of the phraseological competence in a foreign language is widely recognized by many authors (Howarth, Corpas Pastor, Pamies Bertran, to name a few).

We must lose our fear to recognize that the domain of the phraseology is the highest level of command of any language. The objective of the present study is to clarify the differences in UFS Spanish to Arabi

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Publication Date
Wed Jan 17 2024
Journal Name
مجلة كلية بغداد للعلوم الاقتصادية الجامعة
استعمال التحليل الهرمي لتطبيق بطاقة الأداء المتوازن في تقييم الأداء الاستراتيجي للهيئة العامة للأثار والتراث - دراسة تطبيقية
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هدف هذا البحث الى استعمال الأسلوب الرياضي أسلوب التحليل الهرمي وتطبيقه وفق ابعاد بطاقة الاداء المتوازن في تقييم الأداء الاستراتيجي في الهيئة العامة للأثار والتراث، وتمثلت أدوات البحث باستعمال استمارات التحليل الهرمي وطبقت على معايير بطاقة الأداء المتوازن المتمثلة في (المالي، الزبائن، العمليات الداخلية، والتعلم والنمو)، وتم استهداف عينة قصدية متمثلة في رئيس الهيئة والمدراء العامون بعض من مدراء الأقسام ال

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Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Land Use/Cover Change Analysis Using Remote Sensing Data: A Case Study, Zhengzhou Area, Henan Province, China
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In the last two decades, arid and semi-arid regions of China suffered rapid changes in the Land Use/Cover Change (LUCC) due to increasing demand on food, resulting from growing population. In the process of this study, we established the land use/cover classification in addition to remote sensing characteristics. This was done by analysis of the dynamics of (LUCC) in Zhengzhou area for the period 1988-2006. Interpretation of a laminar extraction technique was implied in the identification of typical attributes of land use/cover types. A prominent result of the study indicates a gradual development in urbanization giving a gradual reduction in crop field area, due to the progressive economy in Zhengzhou. The results also reflect degradati

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Publication Date
Sat Mar 30 2013
Journal Name
College Of Islamic Sciences
 المسائل المتعلقة بالأسماء الثابتة لله (عزوجل) الواردة في (مرعاة المفاتيح شرح مشكاة المصابيح، لأبي الحسن المباركفوري (ت1414هـ).
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The research deals with the issues related to the fixed names of God U, which are from a set of issues mentioned in the Book of Observations of the Keys Explaining the Mishkat al-Masbah by Abu Al-Hasan Al-Mubarakfory (d. 141 AH). It included five demands: the first of them is in proving and identifying the most beautiful names and divisions of God, and the second in the name, name and name. And the third: It was in their number, while the fourth: in deriving the names, is it suspensive or not? And Fifth: The Compilation of Allah’s Most Beautiful Names.

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Publication Date
Sun Jan 04 2015
Journal Name
Journal Of Educational And Psychological Researches
المشكلات الاكاديمية التي تواجه طالبات كلية التربية للبنات في الجامعة العراقية من وجهة نظرهن وسبل التغلب عليها
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The present study aimed to identify the problems thatthe students of College of Education, for women in Iraqia university are suffering from and how to overcome them. thesample of the study contained of (392) student which forms (20%) of the basic sample which is  (2180) student, distributed on the six departments of the college they have been chosen randomly and the researcher has used the descriptive analytic method by applying one contains (67) items distributed on six fields,they are as follows: study skills field, academic field, curriculums field, students- teacher relationship field, examinations field, students family field,.

        The study has come with

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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
A Comparison of Parameters Estimation Methods for the Negative Binomial Regression Model under Multicollinearity Problem by Using Simulation
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This study discussed a biased estimator of the Negative Binomial Regression model known as (Liu Estimator), This estimate was used to reduce variance and overcome the problem Multicollinearity between explanatory variables, Some estimates were used such as Ridge Regression and Maximum Likelihood Estimators, This research aims at the theoretical comparisons between the new estimator (Liu Estimator) and the estimators

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Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Field Study of Novel Storage Tank of Solar Water Heating System
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In this paper thermo-hydrodynamic characteristics were investigated experimentally for a new type shell-helical coiled tube heat exchanger used as a storage tank of closed loop solar water heater system. Triple concentric helical coils were made of copper tubes of (12.5mm OD and 10mm ID) with coils diameter of (207, 152.2, 97mm) for outer, middle and inner coils respectively. The experiments were carried out during a clear sky days of (March and April 2012). The parameters studied in this work are: history of average temperature of shell side of the storage tank, collector heat gain, heat rejected from coils to shell side of the storage tank, collector efficiency, thermal effectiveness of the heat exchanger (storage tank), and pressure d

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Publication Date
Fri Mar 31 2017
Journal Name
Journal Of Engineering
Aerodynamic Characteristics of a Rectangular Wing Using Non-LinearVortex Ring Method
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The aerodynamic characteristics of general three-dimensional rectangular wings are considered using non-linear interaction between two-dimensional viscous-inviscid panel method and vortex ring method. The potential flow of a two-dimensional airfoil by the pioneering Hess & Smith method was used with viscous laminar, transition and turbulent boundary layer to solve flow about complex configuration of airfoils including stalling effect. Viterna method was used to extend the aerodynamic characteristics of the specified airfoil to high angles of attacks. A modified vortex ring method was used to find the circulation values along span wise direction of the wing and then interacted with sectional circulation obtained by Kutta-Joukowsky the

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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
ESTIMATION OF THE OPTIMUM BED THICKNESS OF A FLOWTHROUGH POROUS ELECTRODE (FTPE) WORKING UNDER MASS TRANSFER CONTROL
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In this paper, a theoretical analysis of optimum bed thickness operates under mass transfer control for realizing a high efficiency and reaction conversion of an electrochemical reactor has been made based on flowthrough porous electrode (FTPE) configuration. Many models have been used to represent the optimum bed thickness by taking a look into previous works concerned and collecting all related information, data, and models. The parameters that affect the optimum bed thickness have been visualized and reviewed, and almost all of them have been examined by experimental data from different sources and based on the various models. It has been found that the increase in electrolyte flow rate, concentration, limiting current density, and sp

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