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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 Sep 01 2025
Journal Name
Thermal Science And Engineering Progress
Active mixing strategies for energy-efficient water dispensers: Comparative experimental study of impeller and bubble injection in hot climates
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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
The Calculation and Analysis of the Total Electron Content Over Different Latitudes and Seasons Using the Numerical Trapezoidal and Simpson Methods
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It has been shown in ionospheric research that calculation of the total electron content (TEC) is an important factor in global navigation system. In this study, TEC calculation was performed over Baghdad city, Iraq, using a combination of two numerical methods called composite Simpson and composite Trapezoidal methods. TEC was calculated using the line integral of the electron density derived from the International reference ionosphere IRI2012 and NeQuick2 models from 70 to 2000 km above the earth surface. The hour of the day and the day number of the year, R12, were chosen as inputs for the calculation techniques to take into account latitudinal, diurnal and seasonal variation of TEC. The results of latitudinal variation of TE

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Publication Date
Mon Oct 22 2018
Journal Name
Journal Of Economics And Administrative Sciences
Performance Appraisal of Human Resource Management and Its Effect on Achieving the Organizational Success -A Field Search at the Ministry of Oil-
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The present study addressed "Performance Appraisal of Human Resource Management and Its Effect on Achieving the Organizational Success", for the topics of performance appraisal of human resource management and the organizational success gained an increasing interest being relatively important and modern topics which had a great effect on the future of organizations.

The study aimed at revealing the pattern of appraising the performance of human resource management for the study sample, and whether it was qualified to lead the ministry towards the organizational success, for this purpose two main hypotheses were formulated: 1) there is a positive significant correlation between both variables: performanc

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Publication Date
Tue Dec 31 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Causes and Effects of Earnings Management on Stock Prices
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This study uses the performance of the discretionary estimation models by using a sample of listed companies in the Netherlands and Germany. The actual accounting framework provides a wide opportunity for managers to influence data in financial reporting. The corporate reporting strategy, the way managers use their discretionary accounting, has a significant effect on the company's financial reporting. The authors contribute to the literature through enhancement to these models to accomplish better effects of identifying earnings management as well as to present evidence that is particular to the Dutch and German setting.

For this, we followed the methodology of Dechow, Sloan, and Sweeney (1995) and Chan

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Publication Date
Fri Nov 10 2017
Journal Name
Al–bahith Al–a'alami
Qualitative Research in Public Relations An Analytical: Study of Public Relations› Researches in Iraq from 1989 to 2016
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In the mist of developments in the course of scientific research in general and humanities in particular and the accompanying changes in the visions and policies inspired by the need for these sciences to follow the qualitative methods in dealing with many of the topics or problems that require for their solution to obtain qualitative information which can be provided by resorting to quantitative research. Therefore, a new trend has emerged in many public relations› researchers who believe that qualitative research methods should be used by establishing scientific foundations and methodological classification based on the use of these methods and determining the nature of the subjects applied in them to reach results that are character

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Publication Date
Mon Mar 11 2019
Journal Name
Baghdad Science Journal
Results on a Pre-T_2 Space and Pre-Stability
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This paper contains an equivalent statements of a pre-  space, where  are considered subsets of with the product topology. An equivalence relation between the preclosed set  and a pre-  space, and a relation between a pre-  space and the preclosed set  with some conditions on a function  are found. In addition, we have proved that the graph  of  is preclosed in if  is a pre-  space, where the equivalence relation  on  is open.

     On the other hand, we introduce the definition of a pre-stable ( pre-stable) set by depending on the concept of a pre-neighborhood, where we get that every stable set is pre-stable. Moreover, we obtain that

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Publication Date
Sun Jun 30 2013
Journal Name
College Of Islamic Sciences
ا Hadiths prohibiting the intimidation of a Muslim in the six books - an analytical study
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This research deals with the hadiths of intimidation. An analytical study of the serious effects of intimidation in society. Intimidation and intimidation of a Muslim is a serious matter, because of the anxiety, intimidation, and dispossession of others ’rights, but some consider it easy, and others intimidate jokingly or seriously, which may lead to such intimidation to have effects Serious.
For intimidation entails the death of the individual, the disappearance of his mind, or the loss of his money, etc., from here the need was urgent; to show the vision of the prophetic Sunnah in denouncing intimidation, so we had this humble research tagged with (hadiths prohibiting the intimidation of a Muslim in the books The six are an analyt

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Publication Date
Mon Jul 01 2019
Journal Name
مجلة الجامعة العراقية
القياس المحاسبي عن التنمية المستدامة واثره على تقارير الابلاغ المالي نموذج مقترح (دراسة في الشركة العامة للمنتوجات الغازية)
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هدف البحث الى التعرف على القياس المحاسبي عن التنمية المستدامة، وبيان العلاقة بين القياس المحاسبي عن التنمية المستدامة وتقارير الابلاغ المالي، وكذلك بيان أثر القياس المحاسبي عن الاستدامة على تقارير الإبلاغ المالي في الشركة العامة للمنتوجات الغازية، وقد تمحورت مشكلة البحث في بيان أثر عناصر المحاسبة عن التنمية المستدامة، البيئية، والاجتماعية، والاقتصادية، على تقارير الإبلاغ المالي في الشركة العامة للمنتو

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Publication Date
Sat Jan 01 2022
Journal Name
Proceeding Of The 1st International Conference On Advanced Research In Pure And Applied Science (icarpas2021): Third Annual Conference Of Al-muthanna University/college Of Science
Theoretical study and calculation of electronic current flow at platinum metal contact with TFP molecule systems
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Publication Date
Sat Mar 01 2025
Journal Name
Geoenergy Science And Engineering
Empirical model for predicting slug-pseudo slug and slug-churn transitions of upward air/water flow
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A pseudo-slug flow is a type of intermittent flow characterized by short, frothy, chaotic slugs that have a structure velocity lower than the mixture velocity and are not fully formed. It is essential to accurately estimate the transition from conventional slug (SL) flow to pseudo-slug (PSL) flow, and from SL to churn (CH), by precisely predicting the pressure losses. Recent research has showed that PSL and CH flows comprise a significant portion of the conventional flow pattern maps. This is particularly true in wellbores and pipelines with highly deviated large-diameter gas-condensate wellbores and pipelines. Several theoretical and experimental works studied the behavior of PSL and CH flows; however, few models have been suggested to pre

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