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
Sun May 26 2019
Journal Name
Iraqi Journal Of Science
Hydraulic Characteristics of the Aquifer up Al-Khassa Dam Sub-Basin Kirkuk/NE Iraq
...Show More Authors

The aim of this study is to the evaluation of the general hydrogeology condition of the Al-Khassa sub-basin area. Pumping test has been done for five wells in the area. The hydrogeological characteristics (transmissivity, hydraulic conductivity and storage coefficient) were determined in the area by input data which obtained from the pumping test process into the (AquiferWin32, Version 5) software program. The data were analyzed using Copper-Jacob, Theis and Hantuosh methods for pumping, the values of hydraulic characteristics range from: transmissivity (0.98 to 19.57) m²/day in (W7-W9-W10-W12) sites and 416 m²/day in W1, hydraulic conductivity (0.051 to 0.305) m/day in (W7-W9-W10-W12) sites and 5.012 m/day in W1, storage coefficie

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Crossref
Publication Date
Sat Oct 28 2023
Journal Name
Baghdad Science Journal
Newton-Kantorovich Method for Solving One of the Non-Linear Sturm-Liouville Problems
...Show More Authors

Due to its importance in physics and applied mathematics, the non-linear Sturm-Liouville problems
witnessed massive attention since 1960. A powerful Mathematical technique called the Newton-Kantorovich
method is applied in this work to one of the non-linear Sturm-Liouville problems. To the best of the authors’
knowledge, this technique of Newton-Kantorovich has never been applied before to solve the non-linear
Sturm-Liouville problems under consideration. Accordingly, the purpose of this work is to show that this
important specific kind of non-linear Sturm-Liouville differential equations problems can be solved by
applying the well-known Newton-Kantorovich method. Also, to show the efficiency of appl

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Feb 28 2023
Journal Name
Iraqi Journal Of Science
Applications of the Finite Operator〖 〗_3 E_2 (■(q^(-N),a,b@c,d);q,-fθ) for the Polynomials B_n (a,b,c,d,f,x,y|q)
...Show More Authors

     In this work,   polynomials  and the finite q-exponential operator  are constructed. The operator  is used to combine an operator proof of the generating function with its extension, Mehler's formula with its extension and Roger's formula for the polynomials . The generating function with its extension,  Mehler's formula with its extension and Rogers formula for Al-Salam-Carlitz polynomials  are deduced by giving special values to polynomials .

View Publication Preview PDF
Scopus (8)
Crossref (2)
Scopus Crossref
Publication Date
Tue Jan 08 2019
Journal Name
Arab Science Heritage Journal
الأمير كوركوز الاويغوري دراسة في سيرته ودوره السياسي والاداري والاقتصادي والعمراني خلال العصر العباسي 624-641 هـ/ 1226- 1243 م
...Show More Authors

حظيت عدد من الشخصيات التاريخية ممن كان لها أثر واضح المعالم في تطور النظام الإداري والسياسي للإمبراطورية المغولية، بأهتمام عدد لا بأس به من الباحثين.

View Publication Preview PDF
Publication Date
Wed Dec 12 2018
Journal Name
Arab Science Heritage Journal
الحركة مساهمة المرأة في الحركة العلمية من خلال كتاب (( أنباء الغمر بأبناء العمر )) لابن حجر العسقلاني (773هـ/852هـ) (دراسة تاريخية)
...Show More Authors

The search in these subjects makes an importanl accomplishment in the study of the scientific life in that (era)   specialy what the wonen had from a scientific and social level in that(age) the studies of the scientestis which were brilliant in the this era never hed the same as the first scientests . because of the common mistakes toward some resesrchers

View Publication Preview PDF
Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
أهم المشاكل الاجتماعية والنفسية المؤدية إلى الإصابة بمرض الزهايمر لدى كبار السن (دراسة ميدانية لعينة من المصابين في مدينة بغداد)
...Show More Authors

The most important social and psychological problems that lead to Alzheimer's disease in the elderly (field study of a sample of people living in the city of Baghdad). The research aims to: 1. Identify the most important social, psychological and health problems of elderly people with Alzheimer's disease. 2. The most prominent solutions and treatments for people living with this disease. 3. rehabilitation and provision of social, psychological and medical services for people with Alzheimer's disease. The research stages of Alzheimer's disease and its symptoms and the most important causes of Alzheimer's disease, research has strengthened the theoretical framework. The theoretical study unexplained social pressure generating dealt with Al

... Show More
View Publication Preview PDF
Publication Date
Mon Dec 28 2020
Journal Name
Journal Of The College Of Education For Women
Preparing the Arabic Language Teacher for Non-Native Speakers, Following the Experience of the Arabic Language Institute at the International University of Africa: منى يوسف محمَّد وقيع الله
...Show More Authors

The study aims to examine the reality of preparing the Arabic language teacher for non-native speakers by presenting the experience of the Arabic Language Institute at the International University of Africa. Thus, it addresses the following questions: How is it possible to invest the long scientific experiences in proposal and experiment preperations to qualify Arabic language teachers for non-native speakers? What is the reality of preparing an Arabic language teacher at the Institute? How did the Arabic Language Institute process teacher preparation? What are the problems facing the preparation of the Arabic language teachers and the most important training mechanisms used in that Institute?What problems faced the implementation of the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jun 06 2015
Journal Name
مجلة
فعالية استخدام تدريبات القوة الدافعة الذاتية في تطوير القوة الخاصة و بعض القدرات الوظيفية و المهارية للاعبين الشبابا بالكرة الطائرة
...Show More Authors

Publication Date
Wed Oct 01 2008
Journal Name
Journal Of Educational And Psychological Researches
العلاقــة بين المقرر الدراســي والتخصـص والتحصـيل العلمي في الكيميــاء والاتجــاه نحــو العـلوم لدى طلبــة كليــة التربيــة ابن الهيثــم / جامعــة بغــداد
...Show More Authors

تهدف هذه الدراسة إلى معرفة الفرق في التحصيل الدراسي في الكيمياء والاتجاه نحو العلوم بين طلاب التخصص العلمي وطلاب التخصص الصناعي الصف الأول كلية التربية ابن الهيثم، كذلك تهدف الدراسة إلى معرفة العلاقة بين التحصيل الدراسي في الكيمياء ودرجات اختبار نهاية الفصل في الكيمياء، والمعدل التراكمي بعد أخذ المقرر الدراسي والاتجاه نحو العلوم بالنسبة لطلاب التخصص العلمي وطلاب التخصص الصناعي.

لقد است

... Show More
View Publication Preview PDF
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