Preferred Language
Articles
/
joe-2040
Numerical Simulation of 3D- Flow Structure and Heat Transfer for Longitudinal Riblet Upstream of Leading Edge Endwall Junction of Nozzle Guide Vane
...Show More Authors

The simulation have been made for  3D flow structure and heat  transfer with and without

longitudinal riblet upstream of leading edge vane endwall junction of first stage nozzle guide vane .The research explores concept of weakening the secondary flows and reducing their harmful effects.Numerical investigation involved examination of the secondary flows ,velocity and heat transfer rates by solving the governing equations (continuity, Navier -stokes and energy equations ) using the known package FLUENT version (12.1).The governing equations were solved for three dimentional, turbulent flowe, incompressible with an appropriate turbulent model (k-ω,SST) .The numerical solution was carried out for 25 models of V-groove riblet with wide ranges of height (h) and space (s). The results indicated that, the riblet endwall junction was a powerful tool for controlling the flow structure, reducing secondary flow formation,and elimination the effect of heat transfer at leading edg and passage . The drag reduction produced by riblet was proportional with their height and space. V-groove riblet with dimension of (h=1.35mm and s=2.26mm) was found to be the most effective in reduction of drag (2.7%) and heat transfer (21%) so it was selected as an optimum dimension of riblet model. The results also showed that the drag reduction produced by riblet was proportional to their size. The riblet model had a great effect in elimination spanwise ,pitchwise velocities ,but strength the streamwise velocity .At leading edge ,the effect of secondary flow was extended up to 23% from span height and 35% upstream leading edge .The riblet model caused an increase in momentom at a region very close to leading edge and to move stagnation point very close to the leading edge.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Nov 01 2010
Journal Name
Iraqi Journal Of Physics
New Technique for Treatment of the dust accumulation from PV solar panels surface
...Show More Authors

One of the most important problems facing the world today is the energy problem. The solution was in finding renewable energy sources such as solar energy. The solar energy applications in Iraq is facing many problems . One of the most important problems is the accumulation of dust on the solar panels surface which causes decreasing its performance sharply. In the present work, a new technique was presented by using two-axis solar tracking system to reduce the accumulated dust on the solar panel surface and compared it with the fixed solar panels which installed at tilt angles 30° and 45°. The results indicated that the maximum losses of the output power due to accumulation of dust on the fixed solar panels is about 31.4% and 23.1% res

... Show More
View Publication Preview PDF
Publication Date
Mon Feb 02 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Radiographic follow up for clinical cases of mandibular implant retained overdenture MIR-OD
...Show More Authors

Background: The use of osseointegrated fixtures in dentistry has been demonstrated both histologically and clinically to be beneficial in providing long term oral rehabilitation in completely edentulous individual. Most patients suffer from denture instability; particularly with mandibular prosthesis, the use of dental implant will be benefit significantly from even a slight increase in retention. The concept of implanting two to four fixtures in a bony ridge to retain a complete denture prosthesis appealing therefore, as retention, stability and acceptable economic compromise to the expanse incurred with the multiple fixture supported fixed prosthesis. Materials and methods in this study the sample were eight patients selected from a hosp

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
The efficiency calibration for local manufacturing gamma scanning systems of radioactive waste drums
...Show More Authors

The Local manufacturing scanning gamma system designed in Tuwaitha site for nondestructive assay method of radioactive waste drums, where it consist of two main parts with their belongings for controlling the of detector and drum movements up-down and rotation respectively. The volume of the used drum is 220 L with 85 cm height. The drum filled with Portland cement. Six cylindrical holes were made within cement drum and distributed in radial arrangement.The152Eu source inserted in these holes individually, to measure the average angular count rate of gamma radiation. The full energy efficiency value for geometry of drum and detector is computed for thirteen photo peaks. The average efficiency represented by the curve of these peaks indic

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Oct 01 2020
Journal Name
Biochemical And Cellular Archives
HISTOLOGICAL STUDY FOR DEVELOPMENT OF OPTIC TECTUM IN WHITE CHOCKED BULBUL PYCNONOTUS LEUCOTIS
...Show More Authors

Scopus
Publication Date
Wed Oct 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Affect of Financial Development on Poverty in Iraq for the Period 1980-2010
...Show More Authors

There are many applied Economic studies that have found positive nexus between financial development and poverty reduction in developing countries. Iraq has witnessed an increasing rate of poverty during the period 1980-2010 due to many internal and external factors such as wars, economic sanctions, inflation, a high rate of unemployment, and political and security instability. Therefore, the investigation about the solutions to reduce poverty becomes very necessary, and enhancing the financial development in Iraq is one of these options. This is due to that the financial development could reduce the poverty rates through two channels: the first is direct via the offering of the loans and other financial facilities to the poor, a

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Performance Analysis of Four Conceptual Designs for the Air Based Photovoltaic / Thermal Collectors
...Show More Authors

The  thermal  and  electrical  performance  of  different  designs  of  air  based  hybrid photovoltaic/thermal collectors is investigated experimentally and theoretically. The circulating air is used to cool PV panels and to collect the absorbed energy to improve their performance. Four different collectors have been designed, manufactured and instrumented namely; double PV panels without cooling (model I), single duct double pass collector (model II), double duct single pass (model III), and single duct single pass (model IV) . Each collector consists of: channel duct, glass cover, axial fan to circulate air and two PV panel in parallel connection. The temperature of the upper and

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Tue Oct 13 2015
Journal Name
Plos Medicine
P2RX7 Purinoceptor: A Therapeutic Target for Ameliorating the Symptoms of Duchenne Muscular Dystrophy
...Show More Authors

View Publication
Scopus (57)
Crossref (60)
Scopus Clarivate Crossref
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Theoretical Studies of Sum Optical Properties for InAs (001) by Surface Differential Reflectivity
...Show More Authors

The real and imaginary part of complex dielectric constant for InAs(001) by adsorption of oxsagen atoms has been calculated, using numerical analysis method (non-linear least square fitting). As a result a mathematical model built-up and the final result show a fairly good agreement with other genuine published works.

View Publication Preview PDF
Crossref
Publication Date
Thu Mar 22 2018
Journal Name
Association Of Arab Universities Journal Of Engineering Sciences
Assessment of medical solid waste generation rates for teaching hospitals in Baghdad city
...Show More Authors

Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
Design of a PID-Lead Compensator for a Twin Rotor Aerodynamic System (TRAS)
...Show More Authors

This paper deals with a Twin Rotor Aerodynamic System (TRAS). It is a Multi-Input Multi-Output (MIMO) system with high crosscoupling between its two channels. It proposes a hybrid design procedure that combines frequency response and root locus approaches. The proposed controller is designated as PID-Lead Compensator (PIDLC); the PID controller was designed in previous work using frequency response design specifications, while the lead compensator is proposed in this paper and is designed using the root locus method. A general explicit formula for angle computations in any of the four quadrants is also given. The lead compensator is designed by shifting the dominant closed-loop poles slightly to the left in the s-plane. This has the effect

... Show More