Preferred Language
Articles
/
alkej-347
Experimental and Numerical Research on Flow-Induced Vibration in Valves
...Show More Authors

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).

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Sep 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Role of Strategic Flexibility in Achieving Organization Effectiveness: Analytical Research in the Directorates of the Ministry of Education
...Show More Authors

This research aims to know the role of strategic flexibility in achieving organizational effectiveness by studying the dimensions of strategic flexibility (capacity flexibility, resource flexibility, information flexibility, and coordination flexibility) on the dimensions of organization effectiveness (environmental adaptation, productivity and achieving goals) through an analytical study conducted in six directorates in the office of the Iraqi Ministry of Education.

The research problem was represented in the form of questions, the most prominent of which was "What is the role of strategic flexibility in achieving organization effectiveness?" The descriptive analytical approach was relied on in applying

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Aug 03 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Role of Integrated Reporting in Reducing Information Asymmetry: Analytical Research of A sample of Iraqi Banks listed on the Iraq Stock Exchange
...Show More Authors

Allowing Iraqi companies to use multiple systems and policies leads to varying levels of disclosure and no high symmetry between report preparers and users, and that the adoption of integrated reporting can reduce information asymmetry. The theoretical side addressed the concepts of these variables, and in the practical side the binary variable (0, 1) was used. To compensate for the value of the independent variable (integrated reporting) based on the Central Bank of Iraq’s classification of banks according to the (CAMLES) index, and the dependent variable (information asymmetry) was measured through two measures (price difference, unusual return), the research community was represented by (5) Banks out of the total of banks li

... Show More
View Publication Preview PDF
Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The impact of organizational learning in building intellectual capital in public organizations: comparative research between the universities of Baghdad and al-Mustansiriya
...Show More Authors

   Organizational learning is one of the most important means of human resource development in organizations, but most of the organizations, especially public ones do not realize the importance of organizational learning enough, and estimated his role accurately in building intellectual capital, the resource competitive importantly for organizations of the third millennium and who suffers is other end of lack of understanding of its meaning and how to prove its presence and measured in public organizations, so there is the need for this research, which aims to investigate the effect of organizational learning its processes (knowledge acquisition, Information transfer, Interpreting the information, Organizational me

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Feb 28 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Impact of Adequacy and Authoritative Evidences in the Audit Risks: An Exploratory Research for A Sample Views of Auditors in Iraq
...Show More Authors

The Audit evedances represent the reconciliation tools between the Financial data shown on financial statements, and the level of satisfaction level of the Auditor about these statements. According that, the Auditor try to achieve the highest quantity of These evidances, and the most satisfactive of it…, but that will be so hard sometimes, when the internal controlling system is not good, and when the Auditor had some satisfied evidences, but not sharp… So, this research comes to inspect the relation between the quantity, and the level of satisfaction, and argument to prove that evidences gives. This research assumes that getting enough evidences leads to reduce faults, improves the auditing operation, and avoids risks. The research

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jun 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Financing and its impact on municipal performance in the municipalities of Missan governorate for the period (2011-2018)
...Show More Authors

The research aims to show the role or extent of the impact of financing in its various forms on the municipal performance before and after the financial deficit through relying on the analytical research methodology of the research community represented by the Directorate General of Municipalities and the Directorate of Maysan municipalities as a sample of research (13) municipal institutions for a period of (8) years, Considering the completion of the final accounts of these years, which provides the necessary data for the study, in addition to the variation in the quality and amounts of grants allocated to municipal institutions during these years, which gives a clearer and more comprehensive picture of the reality of allocatio

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Vibration Characteristics Oblate Shell "With and Without Framed Structure"
...Show More Authors

This paper presents the results of investigating the vibrational characteristics of oblate dish with and without framed structure . A finite element method, was applied to the dynamic analysis of oblate spheroidal shell. Different types of elements were considered in one dimension and two dimensions. It was found that the natural frequencies of oblate shells had two types of behavior against increasing the shell thickness and eccentricity, which are the membrane mode and bending mode –Since – the membrane modes natural frequencies tend to increase with the increasing the eccentricity of oblate, while the bending modes natural frequencies decrease with the increasing the eccentricity till reach the optimum eccentricity.

 

... Show More
View Publication Preview PDF
Publication Date
Thu May 07 2026
Journal Name
Letters In Biomathematics
Comparison of the Protective Effect of Dapagliflozin and Empagliflozin on Cisplatin-Induced Ovarian Toxicity in Female Rats
...Show More Authors

Background: Cisplatin (CDDP) is an effective chemotherapeutic agent whose gonadotoxicity can lead to premature ovarian insufficiency through oxidative stress, inflammation, and apoptosis. Sodium–glucose cotransporter-2 (SGLT2) inhibitors exhibit cytoprotective effects, but their ovarian effects during chemotherapy remain poorly defined. Methods: Twenty-four female Wistar rats were randomized (n = 6/group) to Control (vehicle), Cisplatin (7 mg/kg, i.p., day 14), Cisplatin + dapagliflozin (DAPA; 0.9 mg/kg/day, p.o., days 1–14), or Cisplatin + empagliflozin (EMPA; 10 mg/kg/day, p.o., days 1–14). At 24 h post-cisplatin, serum estradiol (E2), progesterone, follicle-stimulating hormone (FSH), and Anti-Müllerian Hormone (AMH) were measured

... Show More
Scopus
Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
The role of corporate merger in achieving synergy (Analytical research in a sample of companies of the Iraqi Ministry of Industry and Minerals)
...Show More Authors

The research aims to shed light on the recent experience in the Iraqi business environment, which is the experience of the merger. To evaluate a recent experience in an important sector of the Iraqi business sectors, namely the industrial sector to enable decision-makers to review that experience to judge the extent of its success and address some of the lapses that experience that by measuring synergies can be judged on the success of the merger experience or not. The research community is the governmental industrial sector. The research sample included six cases of merger (14) companies before the merger. The Holt method was used to predict the net sales and total cost values ​​before the merger as if it were not merged. Th

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Visibal management and its implications for Organizational culture A survey of a sample of R & D staff / Ministry of Higher Education and Scientific Research
...Show More Authors

The research aims to shed light on the concept of Visibal management and its reflection on the organizational culture of the organization. The visual administration is a modern administrative method that contributes to the renewal and development of the organization's reality through surveying the opinions of a sample of 61 employees in the R & D / Ministry of Higher Education and Scientific Research. (130) individuals. The questionnaire was used as a main tool for collecting data and information, and their answers were analyzed using the SPSS program in data entry and analysis. The most important tools are computational circles, standard deviations, method of analysis and regression equation. There is a possibility to apply

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The role of practices by the Managing of human resources on effectiveness of organizational crisis Management Described and analysis research for ministry of Iraqi interior
...Show More Authors

The practice by the  administration of human resources  on effectiveness of organization  crisis as two knowledge fields , it were be until now as center for many studies, but the collect it, study of relation between them ,and The role of practices  by the  administration of human resources  on effectiveness of organization  crisis administration  were considered a new study and first according to the available and showing  studies at this field .

The problem of this research was specified by answer for the question that deal for size of consciousness at the ministry of interior for import of&nbs

... Show More
View Publication Preview PDF
Crossref