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 Jun 30 2010
Journal Name
المجلة السياسية والدولية
الدور الاقليمي العراقي :رؤية في الثوابت الاستراتيجية والتحديات المستقبلية :دراسة استشرافية للدور الاقليمي العراقي ومقوماته الاستراتيجية والاقتصادية والسياسية الفرص المتاحه والقيود
...Show More Authors

يناقش البحث المقومات المادية والمجتمعية والموضوعية للدور الاقليمي العراقي بعد العام 2010 والفرص المتاحة والقيود التي تحد منه والافاق المستقبلية لهذا الدور في ظل بيئة اقليمية تسودها منظومات تحالف متناقضة في الاهداف والاستراتيجيات

View Publication Preview PDF
Publication Date
Sun Jan 01 2017
Journal Name
مجلة علوم الرياضة في جامعة ديالى
إتخاذ القرار و علاقته بإنماط الشخصية و الإدراك البنائي لدى مدراء منتديات الشباب و الرياضة في محافظات الفرات الأوسط و الجنوبية.
...Show More Authors

Publication Date
Mon Jun 01 2020
Journal Name
Journal Of The College Of Languages (jcl)
The Labyrinths of the Contemporary French Novel Through the Texts of Patrick Modiano: Les Labyrinthes du Roman Français Contemporain à travers l’Œuvre de Patrick Modiano
...Show More Authors

The current paper aims to study the different forms by which the theme of labyrinth imposes itself as a preferred narrative structure in the novels of the French writer Patrick Modiano. Theoretically speaking, the current research paper will limit itself to the theoretical framework of the textual poetics which relies on the study of literary texts without paying much attention, neither to the context, nor to the life of its author. The analysis of the strong and varied links that Modiano's novels establish with labyrinth represents a field which has not received adequate attention by the critical studies dedicated to this French writer. As it will be shown throughout the current paper, Modiano views labyrint

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تقويم قانون الخدمة الجامعية رقم 23 لسنة 2008 وأثره في تقليل مظاهر الفساد الإداري والمالي: دراسة تحليلية قدية لنصوص القانون وتطبيقاته
...Show More Authors

This research includes an analytical and critique study for the version of the University Service Law No.23 for the year 2008, containing all its aspects and failure whether in its legislation or its applications.

View Publication Preview PDF
Publication Date
Sun Oct 04 2020
Journal Name
وزارة التخطيط/الجهاز المركزي للتقييس والسيطرة النوعية
تحضير وتشخيص ودراسة نظرية وتجريبية لتثبيط تأكل سبيكة الفا- براص في ماء البحر ‏بفعل مثبط تأكل جديد مشتق من 2-امينوبينزوثايوزول
...Show More Authors

يهدف البحث إلى تحضير سلسلة من معقدات العناصر الانتقالية ثنائية التكافؤ(المنغنيز, الكوبلت, النيكل, الخارصين ‏والكادميوم) مع المركب الجديد(‏KL‏) والمشتق من تفاعل ثنائي كبريتيد الكاربون و المركب الوسطي (‏HD‏). شخصت ‏المعقدات ذات الصيغة العامة[‏M(L)2‎‏] بواسطة طيف الرنين النووي المغناطيسي البروتوني والكربوني للمركب الجديد ‏وقياسات الأشعة تحت الحمراء والطيف الإلكتروني ودرجات الانصهار و التوصيلية المولارية و ت

... Show More
Publication Date
Tue Aug 30 2022
Journal Name
مجلة واسط للعلوم الریاضیة
المناخ التنظيمي لشعب الرياضة المدرسية في أقسام الانشطة الرياضية و المدرسية لمحافظة بغداد من وجهة نظر مدرسي التربية الرياضية للمرحلة المتوسطة
...Show More Authors

يهدف البحث الحالي إلى دراسة تأثير المناخ التنظيمي لشعب الرياضة المدرسية في اقسام الانشطة الرياضية على مدرسي التربية الرياضية لأهمية المناخ التنظيمي لما يمثله من الخصائص والسلوكيات التي يتأثر بها العاملون التي قد تتباين من مكان لآخر والبيئة الجغرافية وثقافتها النوعية وذلك باستخدام المنهج الوصفي ولتتحقق من خلال الدراسة الميدانية, يتمثل مجتمع البحث الحالي من مدرسي التربية الرياضية في مدارس محافظة بغداد وال

... Show More
View Publication
Crossref
Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
/ E-Readiness, UTAUT Model, Social Commerce
...Show More Authors

Abstract

Objective / Purpose: Online social relationships through the emergence of Web 2.0 applications have become a new trend for researchers to study the behavior of consumers to shop online, as well as social networking sites are technologies that opened up opportunities for new business models. Therefore, a new trend has emerged, called social trade technology. In order to understand the behavioral intentions of the beneficiaries to adopt the technology of social trade, the current research aims at developing an electronic readiness framework and UTAUT model to understand the beneficiary's adoption of social trade technology.

Design/ methodology/ Approach: To achieve the obje

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Approximate Analytical Solutions of Bright Optical Soliton for Nonlinear Schrödinger Equation of Power Law Nonlinearity
...Show More Authors

This paper introduces the Multistep Modified Reduced Differential Transform Method (MMRDTM). It is applied to approximate the solution for Nonlinear Schrodinger Equations (NLSEs) of power law nonlinearity. The proposed method has some advantages. An analytical approximation can be generated in a fast converging series by applying the proposed approach. On top of that, the number of computed terms is also significantly reduced. Compared to the RDTM, the nonlinear term in this method is replaced by related Adomian polynomials prior to the implementation of a multistep approach. As a consequence, only a smaller number of NLSE computed terms are required in the attained approximation. Moreover, the approximation also converges rapidly over a

... Show More
View Publication Preview PDF
Scopus (12)
Scopus Clarivate Crossref
Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Engineering
Unity Sliding Mode Controller Design for Active Magnetic Bearings System
...Show More Authors

Active Magnetic Bearings (AMBs) are progressively being implemented in a wide variety of applications. Their exclusive appealing features make them suitable for solving traditional rotor-bearing problems using novel design approaches for rotating machinery.  In this paper, a linearized uncertain model of AMBs is utilized to develop a nonlinear sliding mode controller based on Lyapunov function for the electromechanical system. The controller requires measurements of the rotor displacements and their derivatives. Since the control law is discontinuous, the proposed controller can achieve a finite time regulation but with the drawback of the chattering problem. To reduce the effect of this problem, the gain of the uni

... Show More
View Publication Preview PDF
Publication Date
Sun May 06 2007
Journal Name
كلية التربية البدنية وعلوم الرياضة/جامعة بغداد .
تأثير التمرينات الاوكسجينية واللاأوكسجينية في الوحدة التدريبية لتطوير بعض القدرات الوظيفية والبدنية للاعبي كر ة القدم بعمر (13-14)سنة. رسالة ماجستير
...Show More Authors