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 Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of the Effect of Condenser Tubes Distribution for Domestic Refrigerator
...Show More Authors

The performance of a condenser in a domestic refrigerator system without wires and a condenser with a novel design consisted of number of loops as elliptical shape is investigated experimentally in this work. The experiment was conducted with a refrigerator designed to work with HFC134a, under no load and with loads of (1.5,3 and 12 liters of water). In particular, the effects of shape change of the condenser were very important in heat transfer enhancement and reduce of the frictional loss as a result of reducing the pressure drop in the condenser. The results shown that compressor work decreases with elliptical condenser about (8.6% to 11.3%), and then the power consumption decreases also. The performance of household refrigerator with

... Show More
View Publication Preview PDF
Publication Date
Sat Jun 01 2013
Journal Name
Al Mustansiriyah Journal Of Pharmaceutical Sciences
The influence of different concentrations of aqueous green tea extract on methotrexate induced haematological toxicity in rats
...Show More Authors

Methotrexate (MTX), a folic acid antagonist is widely used for the treatment of a variety of tumors. In the present study, the possible protective effect of aqueous green tea extract (AGTE) in methotrexate-induced haematotoxicity was investigated.Four main groups of white Albino rats were used: control group, (MTX) group, following a single dose of MTX (20 mg/kg, i.p.) saline was administered for 5 days. (AGTE) group, was treated with 1.25% concentration of AGTE only for 12 days and the (MTX+AGTE) group, in thism group rats received different concentrations of AGTE (0.625, 1.25 and 2.5%), as their sole source of drinking water, 7days before and 5 days after MTX treatment. MTX induced significant decreases in RBC, Hb, Hct, WBC and pl

... Show More
View Publication
Crossref
Publication Date
Mon Jan 28 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of audit committees in reducing the risk of external Auditors Engagement Regarding Accepting Assignment: An Applied research in a sample of Iraqi private banks And Audit Bureaus
...Show More Authors

The research aims to identify the most important concerns that led to the increase of  interest in the topic of corporate governance and specifically highlighting  the role of the audit committees of the Administration  Board in reducing the risk of the auditor and the rationalization of professional judgments، in particular about accepting  the assignment and setting the fees of the audit process by extrapolating  global experience in this area ، and a field study is conducted for a sample of private Iraqi banks to evaluate the role of audit committees constituted currently per with bank law no. (94) of 2004 and to be acknowledged with actual performance of these committees and their role in recommending the n

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Geotechnical Engineering And Sustainable Construction
Numerical Modeling of Under Reamed Piles Behavior Under Dynamic Loading in Sandy Soil
...Show More Authors

Under-reamed piles defined by having one or more bulbs have the potential for sizeable major sides over conventional straight-sided piles, most of the studies on under-reamed piles have been conducted on the experimental side, while theoretical studies, such as the finite element method, have been mainly confined to conventional straight-sided piles. On the other hand, although several laboratory and experimental studies have been conducted to study the behavior of under-reamed piles, few numer­ical studies have been carried out to simulate the piles' performance. In addition, there is no research to compare and evaluate the behavior of these piles under dynamic loading. Therefore, this study aimed to numerically investigate bearing capaci

... Show More
View Publication
Scopus (2)
Crossref (2)
Scopus Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
EXPERIMENTAL AND THEORETICAL INVESTIGATIONS FOR BEHAVIOR OF PRECAST CONCRETE GIRDERS WITH CONNECTIONS
...Show More Authors

This research presents experimental and theoretical investigation of 15 reinforced concrete spliced and nonspliced girder models. Splices of hooked dowels and cast in place joints, with or without strengthening steel plates were used. Post-tensioning had been used to enhance the splice strength for some spliced girders. The ANSYS computer program was used for analyzing the spliced and non-spliced girders. A nonlinear three dimensional element was used to represent all test girders. The experimental results have shown that for a single span girder using steel plate connectors in the splice zone has given a sufficient continuity to resist flexural stresses in this region. The experimental results have shown that the deflection of hooked do

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Wed Nov 01 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Assessment of ellagic acid action in 5-fluorouracil induced intestinal mucositis: Assessment of ellagic acid action in 5-fluorouracil induced intestinal mucositis
...Show More Authors

The intestinal mucositis define as inflammation and ulceration in the gastrointestinal tract wall and in some case in the oral cavity these cause by treatment with antineoplastic drug like 5-fluorouracil and Irinotecan and other types of chemotherapeutics drugs , 5-Fluorouracil-induced intestinal mucositis (IM) is consider as one of the more common tumor issue .it cause series of undesirables symptoms like severe diarrhea ,abdominal pain , stomach uncomfortable and other. The aim of this current study to see how ellagic acid act to  Attenuates 5-FU-Induced Intestinal Mucositis and  Diarrhea in Mice . we induced the intestinal mucositis by injected the mice intraperitoneally in 5-fluorouracil about 50mg per kg daily for

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Risk measurement and its role in preparing the target cash flow statement and rationalizing administrative decisions
...Show More Authors

Abstract :

The Aims of this research is to describe the concept of risk, its type and method of measurement, and to clarify the impact of these risks on the expected cash flow statement and the preparation of the target cash flow statement that takes these risks into consideration. Because the local economic environment is exposed to many risks, Therefore, this list will be predictive, which will help the economic unit to make administrative decisions, especially decisions related to operational, investment and financing activities. Therefore, the research problem is based on the fact that most of the local economic units are the list of flows According to the actual basis and not according to the discretionary basis (bud

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jun 30 2010
Journal Name
Al-kindy College Medical Journal
Comparative study of the renoprotective effects of captopril and aminophylline against cainst cisplatin – induced nephrotoxicty in rats
...Show More Authors

Background: Cisplatin is one of the most
commonly used anti-cancer drugs , but its
clinical use was limited by its nephrotoxicity .
Methods: In this study we try to investigate the
renoprotective effect of captopril and
aminophylline against cisplatin induced
nephrotoxicity .For this purpose a 36 Sprague
Dawley rats was divided randomly to 6 groups ,
each group consist of 6 rats. The first group
given normal saline and act as control group,
while the other 5 groups given cisplatin ( 7.5
mg/kg ) , captopril ( 60 mg/kg ) , aminophylline
( 24 mg/kg ) , captopril with cisplatin and
aminophylline with cisplatin respectively. All
drugs are given as single dose through
intraperitonial route. After 6

... Show More
View Publication Preview PDF
Publication Date
Thu Mar 30 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Therapeutic Effects of Melatonin in Lead-Induced Toxicity in Rats
...Show More Authors

           Exposure to lead results in significant accumulation in most of vital organs, and free radical damage has been proposed as a cause of lead-induced tissue damage, where oxidative stress is a likely molecular mechanism. This study was designed to evaluate therapeutic effects of melatonin in lead-induced organ toxicity in rats. The therapeutic effects of melatonin on lead induced toxicity in rats were evaluated using 36 rats, which were allocated into 3 groups and treated as follows: Group I, includes 12 rats injected subcutaneously with 0.2 ml physiological saline for 30 days, followed by treatment with a daily dose of 20mg/kg melatonin, administrated I.P for the successive 30 da

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Tue Oct 20 2020
Journal Name
Journal Of Research In Medical And Dental Science
The Effect of Chicken Eggshell Extract on Microhardness of Artificially Induced Dental Erosion in Permanent Teeth (In Vitro Study)
...Show More Authors

The Effect of Chicken Eggshell Extract on Microhardness of Artificially Induced Dental Erosion in Permanent Teeth (In Vitro Study), Shatha A Abbas*, Alhan A Qasim

View Publication Preview PDF