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
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
...Show More Authors

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 )
.

                                              &nbs

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
بعض الاضطرابات السلوكية والانفعالية والانفعالية وعلاقتها بالاستعمال المفرط للألعاب الالكترونية لدى التلاميذ في المرحلة الابتدائي
...Show More Authors

سعى البحث الحالي الى التعرف على بعض الاضطرابات السلوكية والانفعالية وعلاقتها بالاستعمال المفرط للالعاب الالكترونية لدى تلاميذ المرحلة الابتدائية, إذ يواجه التلاميذ مشكلات سلوكية عديدة ،تظهر من خلال تعاملهم مع اقرانهم في البيت او في المدرسة والتي قد تتطور عند بعضهم وتتحول الى اضطرابات نفسية،مما يؤدي بهم الى ضعف التعلم وسوء التوافق في حياتهم المدرسية ويصبحون عُرضة للا صابة بالامراض النفسية ،إذا لم يتم تشخ

... Show More
View Publication Preview PDF
Publication Date
Wed Nov 14 2018
Journal Name
Arab Science Heritage Journal
تأثير تأثير الحضارة الأندلسية في الحضارة الأوربية انتقال أصناف من الأغذية إلى مائدة الطعام الأوروبية
...Show More Authors

       The progress that happened in Andalusia civilization was affected  by Arabic through taking care of agriculture by entering of new kinds of planets that were more important as political sides which led to prominence new kinds of food transported to Europe that had showed a real reflect of how chat of civilization among people who had lived in various ages until now

View Publication Preview PDF
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
...Show More Authors

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

... Show More
View Publication Preview PDF
Publication Date
Sun Sep 27 2026
Journal Name
Journal Of Physical Education
Standard Levels of Modern Administration for the Iraqi Central Olympic Committee's Olympic Federations
...Show More Authors

The problem of the research lies in the lack of standard levels for modern administration as a guide for evaluating weaknesses and strengths as well as finding solutions. The aim of the research lies in identifying standard levels for modern administration in Iraqi central Olympic committee and international federations. The subjects were (24) Olympic committee' federations. All procedures were standardized to fit our modern administration work. The data was collected and treated using proper statistical operations. The researcher concluded standard levels for modern administration in international federation of the Iraqi Olympic committee, in addition to that he concluded that most administrations levels ranged within four levels (good, fa

... Show More
View Publication Preview PDF
Publication Date
Sun Sep 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Using Six-Sigma to measure the quality performance of the Department of Statistics-University of Baghdad-Case Study
...Show More Authors

Abstract

            This research was to provide a definition of quality, dimensions and concepts, whether traditional or modern concept, as well as review the dimensions of quality in higher education and vision and mission with the overall objectives of the Statistics Department.

         After reviewing quality goals and purposes achieved as well as the mechanisms used to achieve them. and use standard Six-Sigma as one of the methodologies used in quality with the historical roots of using this methodology and methods applied and their definitions t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Planner And Development
نظام الفعالية السكنية ومستوى الضوضاء الحالة الدراسية:- منطقة سكنية في مدينة اربيل/ منطقة راستي الجديدة
...Show More Authors

View Publication Preview PDF
Publication Date
Sat Nov 10 2018
Journal Name
Journal Of Planner And Development
(دور الوعي البيئي لدى الأسرة العراقية في التخلص من النفايات الصلبة) (مدينة الرمادي – حي العزيزية)
...Show More Authors

View Publication Preview PDF
Publication Date
Wed Dec 28 2022
Journal Name
Al–bahith Al–a'alami
Interactivity of iraqi daily newspapers sites an analytical study of the websites of al-mada,al-zaman.al-sabahand tareqal-shaab newspapers
...Show More Authors

A study of interactivity in the Iraqi newspaper sites_ An analytical study of the website of Al-Mada, Al-Zaman, Al-Sabah and Tariq Al-Shaab newspaper sought to determine the amount of interactivity in the sites of Iraqi newspapers that have been published since 2003, which consists of (15) newspapers according to the statistics of the Iraqi Books and Documents House.

and the researcher conducted an analytical survey on these sites, and the percentage of interactivity in general was weak, not more than (47.1%), and this weakness in interactivity contributed greatly to the decline in surfers of the websites of those electronic newspapers.

The highest aggregate rate of the research sample was in the simple interactive tools

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Nov 13 2018
Journal Name
Arab Science Heritage Journal
التحديات التحديات المعاصرة للثقافة الإسلامية دراسة في الصورة النمطية المتبادلة للسلام وللحرب بين الإسلام والغرب
...Show More Authors

Islamic Culture face many challenges Such as، Secularism، westrenism، globalism and Colonialism under current attempts For western States and united states of America to dominate on world and Confront all her Opponent Polaris it be clear when U. S. A. Occupied Afghanistan and Iraq and Threatened many Arabic and Islamic States

View Publication Preview PDF