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
Mon Jan 01 2018
Journal Name
وقائع المؤتمر الدولي 7 للغة العربية / دبي
تقويم اداء اساتذة اللغة العربية العامة في كلية الادارة والاقتصاد جامعة بغداد من وجهة نظر طلبتهم
...Show More Authors

Publication Date
Sun Mar 20 2005
Journal Name
الجامعة المستنصرية / كلية التربية الأساسية
اثر استخدام استراتيجية بوليا واستراتيجية التمثيل المعرفي في تحصيل واستبقاء مادة الرياضيات لدى طلبة المرحلة المتوسطة
...Show More Authors

Publication Date
Fri Dec 31 2021
Journal Name
Iraqi Journal Of Laser
Hong-Ou-Mandel Dip Measurements of Two Independent Weak Coherent Pulses for Free Space Quantum Key Distribution Systems
...Show More Authors

Preparation of identical independent photons is the core of many quantum applications such as entanglement swapping and entangling process. In this work, Hong-Ou-Mandel experiment was performed to evaluate the degree of indistinguishability between independent photons generated from two independent weak coherent sources working at 640 nm. The visibility was 46%, close to the theoretical limit of 50%. The implemented setup can be adopted in quantum key distribution experiments carried out with free space as the channel link, as all the devices and components used are operative in the visible range of the electromagnetic spectrum.

View Publication Preview PDF
Publication Date
Sun Jun 27 2021
Journal Name
Iraqi National Journal Of Nursing Specialties
Evaluation of Pregnancy-related Health Behaviors' Change during Pregnancy for Pregnant Women Attending Abo Ghareeb Primary Health Care Sector
...Show More Authors

Objective(s): The study aims at evaluating pregnancy-related health behaviors for pregnant women, and to identify the association between pregnancy-related health behaviors and their demographic characteristics of pregnant woman’s age, education, employment, residential area and monthly income.
Methodology: A descriptive study is carried out for the period from December 14th, 2020 to June 20th, 2021. This study was conducted through a non-probability (convenience) sample of 150 pregnant women attending, Abo Ghareeb primary health care sector in Abo Ghareeb spend. The sample has been collected by using the instrument to gather data and accomplish the study's objectives. A questionnaire is composed of (29) items and it is divided into

... Show More
View Publication Preview PDF
Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Using Project Management Maturity Model to Evaluate Construction Sector -Organizations. Case Study at the Department of buildings - Karkh first
...Show More Authors

The education sector suffers from many problems, including the scarcity of schools that can absorb the increasing number of students in light of the increasing population growth rate, as some regions suffer from a lack of opening of new schools or the expansion of existing schools to increase their capacity so that attention is required. The research sought to identify the level of maturity of project management at the research site (Building Department in Al-Karkh I/ Ministry of Education) Being responsible for educational projects and their implementation and to know that, the ten areas of the knowledge guide to project management PMBOK have been adopted according to the PM3 model (one of the models of maturity

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Aug 01 2018
Journal Name
قضايا سياسية
اشكالية التنافس الامريكي -الروسي دراسة في السلوك السياسي الخارجي حيال المنطقة العربية(دراسة انموذج الحالة السورية)
...Show More Authors

يعد موضوع التنافس بين القوى الكبرى من الموضوعات المستقبلية المهمة التي تؤشر لنا جانبا من صور العلاقات الدولية التي تتسم بالصراع والتعاون من ناحية، والتعاون والتنافس من ناحية أخرى، وبقدر تعلق الموضوع بالمنطقة العربية التي تعد إحدى أهم المناطق العالمية إثارة في مستوى التفاعلات بأنساقها المختلفة، كونها منطقة لازالت محكومة بعوامل غير مستقرة، تشكل نافذة فاعلة لتدخلات القوى الكبرى الساعية إلى إعادة تشكيل المد

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Diagnosis of the reality of marketing knowledge management"A survey of the views of a sample of telecom operatorsIn the city of Sulaymaniyah "
...Show More Authors

This research aimed to diagnose the perception based on Telecommunications of Iraq to the importance of activating knowledge management marketing in possession, as well as Indication of impediments to activate the management of marketing knowledge in the researched companies, also aimed to show the extent of the existence of significant differences in perception based on Telecommunications Iraqi importance of activating the management marketing knowledge in possession. To achieve the objectives of this research, the questionnaire was developed and distributed to a sample of telecommunications companies in the city of Sulaimaniya, was selected on the criterion according to the company's life in terms of seniority in the telecommunication

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jul 22 2019
Journal Name
Arab Science Heritage Journal
الاسطوغرفيا العثمانية التركية حول ثيمة محمية الجزائر في الفترة العثمانية ما بين - الموضوعية العلمية والذاتية المؤدلجة
...Show More Authors

تضمّنت الاسطوغرافيا العثمانية التركية حول ثيمة محمية الج ا زئر في -
الفترة العثمانية مؤلفات صُبغت بعضيا بطابع الموالاة والتحيّز

View Publication Preview PDF
Publication Date
Sat Jun 18 2022
Journal Name
Al-academy
دراسة مقارنة بين التعبير اللفظي والتعبير غير اللفظي في إخراج الدراما التلفزيونية المترجمة – جاك بريفير (أنموذجاً).
...Show More Authors
يهدف البحث الى اشاعة الدراسة المقارنة للنص المترجم الى اللغة العربية لتلافي الفوارق بين النص الأصلي (الأجنبي ) والنص المترجم (العربي ) من حيث المعاني والرموز والمعالجات الفكرية ... الخ .والتأكيد على استعمال التقنيات التربوية (السمعية والبصرية ) في الترجمة الانسانية (المتخصصة ) والاستعانة بالترجمة الآلية لتجنّب متاعب الترجمة والفهم الخاطىء او المنقوص ...للوصول الى فهم واسع بتدريس مادة الاخراج التلف
... Show More
View Publication Preview PDF
Publication Date
Thu Mar 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Using Truncated Test for Finding the Parameters of Single Sampling Plan under Distribution of Log-Logistic
...Show More Authors

A group of acceptance sampling to testing the products was designed when the life time of an item follows a log-logistics distribution. The minimum number of groups (k) required for a given group size and acceptance number is determined when various values of Consumer’s Risk and test termination time are specified. All the results about these sampling plan and probability of acceptance were explained with tables.

View Publication Preview PDF
Crossref