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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
Thu Dec 01 2011
Journal Name
Journal Of Engineering
THEORETICAL AND EXPERIMENTAL STUDY ON THERMAL PERFORMANCE OF CLOSED WET COOLING TOWER
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Thermal performance of closed wet cooling tower has been investigated experimentally and theoretically
in this work. The theoretical model based on heat and mass transfer equations and heat and mass transfer balance equations which are established for steady state case. A new small indirect cooling tower was used for conducting experiments. The cooling capacity of cooling tower is 1 kW for an inlet water temperature of 38oC, a water mass velocity 2.3 kg/m2.s and an air wet bulb temperature of 26oC. This study investigates the relationship between saturation efficiency, cooling capacity and coefficient of performance of closed wet cooling tower versus different operating parameters such wet-bulb temperature, variable air-spray water fl

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Publication Date
Sat Mar 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Strategic Performance Evaluation Using Benchmarking Technique: Applied Research In The Sample Of Offices Of Inspectors General
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In light of the rapid changes in the business environment and the entry of administrative leaders in the challenges of the atheist and twenty- increasing competition between sectors and the desire to acquire the skills, the traditional methods are no longer viable, which requires doing evaluates performance according to a more holistic, rather than limiting the performance evaluation on the financial hub that has not longer enough alone, as well as benchmarking method that has proven successful in developed countries as a way to develop and improve products and services.

I've touched your search to the development of indicators evaluating the performance and preparation of a mechanism for making comparisons of reference between o

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Publication Date
Fri Aug 28 2020
Journal Name
Iraqi Journal Of Science
ON Numerical Blow-Up Solutions of Semilinear Heat Equations
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This paper is concerned with the numerical blow-up solutions of semi-linear heat equations, where the nonlinear terms are of power type functions, with zero Dirichlet boundary conditions. We use explicit linear and implicit Euler finite difference schemes with a special time-steps formula to compute the blow-up solutions, and to estimate the blow-up times for three numerical experiments. Moreover, we calculate the error bounds and the numerical order of convergence arise from using these methods. Finally, we carry out the numerical simulations to the discrete graphs obtained from using these methods to support the numerical results and to confirm some known blow-up properties for the studied problems.

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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Leadership Skills and their Impact on Strategic Planning: Applied Research in the Iraqi Ministry of Planning
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The present search addressed the " leadership skills and their impact on strategic planning " Where has the objective of leadership skills and strategic planning of increasing importance at the present time , for being fairly modern topics ,which have a tremendous impact on the success of organizations..                                                                        &n

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Publication Date
Thu Jan 04 2024
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of agricultura insuranc risk management in achieving the economic development: Applied research in the National Insurance Company
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Abstract                                                    

           The research aims to investigate the existence of correlations and influence between agricultural insurance risk management and economic development in the National Insurance Company with farmers, as agriculture is one of the leading branches of the national economy, ensuring food security and eliminating poverty to ensure sustainable ec

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Publication Date
Tue Feb 16 2016
Journal Name
The Iraqi Journal Of Agricultural Sciences
MEASURING VIBRATION AT TRACTOR PLATFORM , STEERING WHEEL AND SEAT EFFECTIVE AMPLITUDE TRANSMISSIBILITY FACTOR DURING OPERATION TILLAGE
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Field experiment conducted to measure vibrations on three axes longitudinal X, lateral Y and vertical Z on steering wheel, platform tractor and vertical vibration in seat tractor and seat effective amplitude transmissibility (SEAT) factor during operation tillage in silt clay loam soil with depth 18 cm in Baghdad. Split – split plot design under randomized complete block design with three replications least significant design 5 % used. Three factor were used in this experiment included two types of plows included chisel and disc plows which represented main plot, three tires inflation pressure was second factor included 1.1 ,1.8 and 2.7 bar, and three forward speeds of the tillage was third factor included 2.35 , 4.25 and 6.50 km/hr. Resu

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Relationship marketing orientation to improve the quality of service applied research in some Iraqi mobile phone companice
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      This research is based on  interaction of two most important variables to the business organizations in the current era ,  these two variables are (marketing orientation and quality of service),  this research is trying to urge the service organizations to reconsider the mechanisms adopted in the formulation of its plans, It was the application of research in Korek Telecom and Asia Cell Telecom as a sector of service active and important in the business sector in Iraq, the information was obtained through the design of the Likert questionnaire , it was distributed (92) questionnaire , (50) for the company Korek Telecom and (42) of the Asia-Cell and represent research population sample

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of big data analytics in measuring and analyzing the quality costs of economic units : applied research in the Iraqi company for seed production
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                The research aims to explain the role of huge data analyzes in measuring quality costs in the Iraqi company for the production of seed, and the research problem was diagnosed with the weakness of the approved method to measure quality costs, and the weak traditional systems of data analyzes, the researcher in the theoretical aspect relied on collecting sources and previous studies, as well as Adoption of the applied analytical approach in the practical aspect, as a set of financial analyzes were applied within the measurement of quality costs and a statement of the role of data analyzes in the practical side, the research concluded to a set of conc

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Publication Date
Sun May 02 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Evaluating the level of performance according to the tax diagnosis TADAT: applied research in the General Tax Authority
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The aim of the research is to indicate the degree of arrangement of the tax branches discussed and the level of efficiency of their performance according to the dimensions approved in the tax diagnostic tool (TADAT). The checklist has been approved as a main tool in collecting data and information from the tax branches of the General Authority for Taxes and the number (8) branches represented by (Karrada , Karakh Center, Al-Rusafa, New Baghdad, Al-Dora, Karakh Al-Tafim, Al-Kadhimiya, Al-Bayaa),  The statistical program (spss) was used to calculate the weighted arithmetic media, and we reached the research to a number of conclusions, the most important of which were: - Each of the subsections (Karkh Al-Ahram and Karrada) achieved an

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Publication Date
Wed Dec 25 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Peaceful settlement as a means of preventing tax: An applied research in the General Commission for Taxation evasion
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The reconciliation of tax reconciliation is one of the legal methods used by the financial authority in Iraq, which is done with the taxpayer

The research dealt with the weakness of tax revenues for many reasons, including tax evasion, which led to the search for ways to reduce evasion to increase the tax revenue, and settlement reconciliation one of these means .

The research proceeded from the premise that the use of a more broadly settled settlement would govern the tax evasion of taxpayers.

The researchers used a series of studies and previous research, books and other sources related to the subject of research, and this was done through the theoretical framework, and the practical aspect that included the fin

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