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 Dec 01 2013
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Obstacles in Marketing Comprehensive Automobile Insurance Policy: بحث أستطلاعي في شركة التأمين الوطنية
...Show More Authors

Comprehensive automobile insurance is considered as an important branches in the portfolio of National Insurance Company in Iraq .Due to the continous accidents the company is endeavouring to   this market.

    The company faces several obstacles and limitations in marketing the policies of this portfolio due to certain factors and influences beyond the control of the company and others internal mainly connected with the reduction of the marketing programmes of the company .

    The target of this study is  to focus the light  upon the interal factors which can be gorerned by the company,confronted and solved.

 

View Publication Preview PDF
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Walled Nano-Carbon on the Physical, Thermal and Mechanical Properties of Epoxy
...Show More Authors

The physical, the thermal and the mechanical properties of Nano-composites, that consisted of Polyprime EP epoxy that reinforced by multi-walled carbon nanotubes (MWCNTs), have been studied. Various loading ratios, 0.1, 0.5, and 1 wt. %of MWCNT shave been infused into epoxy by a magnetic stirrer and then the hardener mixed with the mthat supplied with the epoxy. All sample shave been cutting using CNC machine. Tensile test, three-point bending, hardness tests, lee's disk, differential scanning calorimetry, water absorption and dielectric and electrical conductivity test were utilized on unfilled, MWCNT-filled epoxy to identify the loading effect on the properties of materials. Scanning electron microscopy (SEM) was used to determine the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 19 2026
Journal Name
Al–bahith Al–a'alami
Students and Watching Specialized Satellite Channels (Applied Study on a Sample of University of Baghdad’s Students
...Show More Authors

This research is one of the public research aimed at identifying the communication habits and the implications of the content on the communication process, especially as the audience of specialized media is often characterized by effectiveness, depth and active in tracking the media message and interaction with its content. It means such audience is a positive, very active, dynamic, and very alert audience driven by his interests and psychological needs to watch specific programs meet his desires.

This satisfaction can only be achieved through the use of specialized media capable of producing programs that will communicate and interact between the ideas you present and this audience.

The phenomenon of specialized satellit

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Nov 10 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of Instructional Intervention on Medical and Health Information of Patients with Diabetes Mellitus Type II
...Show More Authors

Objective: The objectives of the present study were to evaluate the effectiveness of the instructional intervention
about medical and health knowledge of patients with diabetes mellitus type II.
Methodology: A Quasi- experimental study was carried out in National Center for Diabetes Mellitus/ Almustansria
University, started from 4th January 2012, to 1st April 2012. Non-probability (purposive sample) of (50) diabetes
mellitus type II, who visit National Center for Diabetes Mellitus/ Almustansria University. The study sample is
divided equally into (25) study and (25) control groups. The study group received the instructional intervention.
While the control not exposed to the instructional intervention. The data are coll

... Show More
View Publication Preview PDF
Publication Date
Fri Sep 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Charge Stratification and Fuel/Air Ratio Effect on the Efficiency of (ICADE) I. C. Engine Cycle
...Show More Authors

The Isolated Combustion and Diluted Expansion (ICADE) internal combustion engine cycle combines the advantages of constant volume combustion of the Otto cycle with the high compression ratio of the Diesel cycle.   This work studies the effect of isolated air mass (charge stratification) on the efficiency of the cycle; the analysis shows that the decrease of isolated air mass will increase the efficiency of the cycle and the large dilution air mass will quench all NOx forming reactions and reduce unburned hydrocarbons. Furthermore, the effect of Fuel / Air ratio on the efficiency shows that the increase of Fuel / Air ratio will increase efficiency of the cycle.

View Publication Preview PDF
Publication Date
Fri Jun 20 1930
Journal Name
College Of Islamic Sciences
Prison and imprisonment   And their impact on the strengthening of power In the Qur'anic perspective
...Show More Authors

Prison and imprisonment  
And their impact on the strengthening of power
In the Qur'anic perspective

View Publication Preview PDF
Publication Date
Sun Oct 01 2023
Journal Name
Journal Of Photochemistry And Photobiology A: Chemistry
Facile assembly of CoS/Ag2MoO4 nanohybrids for visible light-promoted Z-type-induced synergistically improved photocatalytic degradation of antibiotics
...Show More Authors

View Publication
Scopus (39)
Crossref (33)
Scopus Clarivate Crossref
Publication Date
Wed Sep 29 2021
Journal Name
Al-khwarizmi Engineering Journal
Simulation of a Self-Balancing Platform on the Mobile Car
...Show More Authors

       

In the last years, the self-balancing platform has become one of the most common candidates to use in many applications such as flight, biomedical fields, industry. This paper introduced the simulated model of a proposed self-balancing platform that described the self–balancing attitude in (X-axis, Y-axis, or both axis) under the influence of road disturbance. To simulate the self-balanced platform's performance during the tilt, an integration between Solidworks, Simscape, and Simulink toolboxes in MATLAB was used. The platform's dynamic model was drawn in SolidWorks and exported as a STEP file used in the Simscape Multibody environment. The system is controlled using the proportional-integral-deriva

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The instrumental support search strategies and avoid coping to psychological stressors and their relationship to the cognitive motivation of Al-Anbar University students.
...Show More Authors

the Current research aims to identify the psychological stressors coping strategies and their relationship to the cognitive motivation among Al-Anbar University students through the following hypotheses: 1) no statistically significant differences at a level (0.05) among the sample according to the instrumental support strategy depending on the variable type and specialization, 2) No statistically significant differences at a level (0.05) among the sample in regard of coping avoiding strategy depending on the variable type and specialization, 3) There is no statistically significant difference at a level (0.05) in cognitive motivation level among Al-Anbar University students, 4) No statistically significant differences at a level (0.05)

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 01 2017
Journal Name
Archive Of Mechanical Engineering
Using the Lid-Driven Cavity Flow to Validate Moment-Based Boundary Conditions for the Lattice Boltzmann Equation
...Show More Authors
Abstract<p>The accuracy of the Moment Method for imposing no-slip boundary conditions in the lattice Boltzmann algorithm is investigated numerically using lid-driven cavity flow. Boundary conditions are imposed directly upon the hydrodynamic moments of the lattice Boltzmann equations, rather than the distribution functions, to ensure the constraints are satisfied precisely at grid points. Both single and multiple relaxation time models are applied. The results are in excellent agreement with data obtained from state-of-the-art numerical methods and are shown to converge with second order accuracy in grid spacing.</p>
View Publication
Scopus (23)
Crossref (19)
Scopus Crossref