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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
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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Publication Date
Thu Nov 16 2023
Journal Name
مجلة كلية الإمام الكاظم
الوعي بالمسؤوليةً البيئيـة عنـد طلبـة الكيـمياء فـي كــلية التـربية للعلـوم الصـرفة – أبن الهيثم في العراق
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Publication Date
Mon Oct 10 2016
Journal Name
مجلة الادارة والاقتصاد
تحليل وقياس العلاقة بين نسبة تفضيل السيولة ومعدل التضخم في الاقتصاد العراقي للمدة 1990-2016
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تفضيل السيولة - تضخم جانب الطلب - الاستقرار النقدي - معدل التضخم

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Publication Date
Thu Dec 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
اتجاهات تطوير أنشطة الرقابة الداخلية لتلبية متطلبات لجنة التدقيق: دراسة تطبيقية في مصرف اشور الدولي
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The audit committee has received considerable attention from international institutions and researchers as a result of financial failures and the collapse of major international companies, especially cases of manipulation and misinformation in the financial statements, due to the role played by one of the mechanisms of control of economic entities to increase disclosure and credibility of information published, In overseeing the preparation of financial reports, following up the internal auditing functions, supporting the external auditor and enhancing his independence, and strengthening the shareholders' confidence in the economic entity. The two researchers prepared the applied side of the research by applying a proposed model based on

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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Level of Administrative Work Quality of Private Schools Principals at Southern Governorates of Palestine form the Teachers Point of View
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The study aimed at identifying the level of administrative work quality of private Schools principals at Southern Governorates of Palestine from the teachers' point of view in their schools. To achieve the objectives of this research, a questionnaire was prepared by the researcher consisted of (28) items. It was applied to a sample of (350) teachers. The researcher adopted the descriptive-analytical approach. The results of the study showed that the degree to which principals of private schools in the southern governorates of Palestine practice Administrative Work Quality from the viewpoint of their teachers was very high, with relative weight (85.00%). The results also showed that there are statistically significant differences at the l

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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
Mon Oct 01 2018
Journal Name
Journal Of Educational And Psychological Researches
تقويم محتوى كتاب الاحياء للصف السادس العلمي من وجهة نظرمدرسي ومدرسات الاحياء في محافظة كركوك
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The present study aims to identify the extent to which biology book of sixth grade achieves the basic scientific aspects in light of its scientific objectives. To achieve this goal, the researcher needed to build two questionnaires to evaluate the biology book for sixth-grade. To answer the questions of the study, the researcher used the following statistical methods : the weighted average, and percentages; and to identify the extent to match the perspective of teachers of the material with the perspective of a researcher in each paragraph of the questionnaire as well as the degree of severity of each paragraph in the book neighborhoods sixth-grade has reached Aalbagesh to several of the most important results: 1. All the teachers were w

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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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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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