Preferred Language
Articles
/
joe-1553
Numerical Investigation of Aerodynamic Characteristics of Supercritical RAE2822 Airfoil with Gurney Flap
...Show More Authors

Gurney flap (GF) is well-known as one of the most attractive plain flaps because of the simple configuration and effectiveness in improving the lift of the airfoil. Many studies were conducted, but the effects of GF on the various airfoil types need to be further investigated. This study aimed to clarify the effect of GF in the case of the supercritical airfoil RAE2822. This research includes a steady, two-dimensional computational investigation carried out on the supercritical airfoil type RAE-2822 to analyze Gurney flap (GF) effects on the aerodynamic characteristics of this type of airfoil utilizing the Spalart-Allmaras turbulence model within the commercial software Fluent. The airfoil with the Gurney flap was analyzed for three different height values 1%c, 2%c, and 3%c, and five mounting angles (30°,45°,60°,75°, and 90°) with the axial chord for angles of attack (-1°,-2°,-3°,0°,1°,2°,3°). The calculations showed that when GF height is increased, the maximum suction pressure on the upper surface increases by 25.4%, 36.5%, and 68.83% when the height of the Gurney flap is 1%c, 2%c, and 3%c, respectively, compared with that on the airfoil without GF. The lift coefficient was also increased, and the shock waves moved downward by increasing GF height. As Gurney flap heights increase, the drag coefficient increases gradually for positive angles of attack but for negative angles of attack. The drag coefficient also decreases with increasing the GF heights. As long as the angle of the mounting is between 45o and 90o, the lift coefficient does not differ on a large scale. For mounting angles less than 45o, the lift coefficient drops quite fast. As a result, reducing the Gurney flap’s lift enhancement and the drag coefficient increases gradually for positive angles of attack, but for negative angles, it can be noted that the drag coefficient decreases with increasing the mounting angles of GF. The calculated values of the lift and drag coefficients with an attack angle and pressure coefficient compared with the experimental values, and a good agreement was noticed. 

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed May 28 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Assessment of mandibular radiomorphometric indices as predictors of osteoporosis in postmenopausal women (Cephalometric reconstructed computed tomographical study)
...Show More Authors

Background: Osteoporosis affects almost all of the bones in the female body; the most important one in the facial bone is mandible. Menopause is defined as an absence of the menses for one year. During this time, estrongen, progesterone and ovarian androgens production are diminished due to adult onset ovarian failure which leads to osteoporosis. This study aimed to evaluate the use of computed tomography mandibular morphometric indices for the assessment of pre and postmenopausal osteoporotic women. Subjects and material: This study conducted on 50 Iraqi females divided into 2 groups 20 -30years old as a control group and over50 years old as a study group attending Al-Karkh hospital, Department of Computed Tomography.(each group25 female).

... Show More
View Publication Preview PDF
Publication Date
Fri Dec 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Determination of Implant Primary Stability: A Comparison of the Surgeon’s Tactile Sense and Objective Measurements
...Show More Authors

Background: Evaluation and measurement of primary stability could be achieved by several methods, including the resonance frequency analysis (RFA) and implant insertion torque (IT) values. The need for a sufficient primary stability, guaranteed by an adequate insertion torque and implant stability quotient values, increased its importance mainly in one stage implants or in immediate loading protocols. The aims of this study was to find if there is a correlation between the peak insertion torque (PIT) and ISQ values of implants inserted in the jaws of different bone quality which regarded as two important clinical determinant factors for prediction of implant primary stability, and to evaluate and compare whether an experienced clinician cou

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 05 2017
Journal Name
Baghdad Science Journal
Preparation and study of the structural and optical properties of Bi2S3 thin films by Spray pyrolysis method
...Show More Authors

In this research Bi2S3 thin films have been prepared on glass substrates using chemical spray pyrolysis method at substrate temperature (300oC) and molarity (0.015) mol. Structural and optical properties of the thin films above have been studied; XRD analysis demonstrated that the Bi2S3 films are polycrystalline with (031) orientation and with Orthorhombic structure. The optical properties were studied using the spectral of the absorbance and transmission of films in wavelength ranging (300-1100) nm. The study showed that the films have high transmission within the range of the visible spectrum. Also absorption coefficient, extinction coefficient and the optical energy gap (Eg) was calculated, found that the film have direct ener

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Wed Jan 02 2019
Journal Name
Journal Of Educational And Psychological Researches
Obstacles to women's access to the positions of leadership in the university from their point of view
...Show More Authors

The problem of research is the need to find out the obstacles and difficulties facing women in accessing leadership positions at the University of Baghdad from their point of view. The importance of research comes from the importance of women in the university and their vital role in the development of society. The research objectives summarized the most important obstacles facing women Access to the leadership positions in the university and the relative weight of these obstacles as well as trying to identify differences in their view of these obstacles according to the variables of specialization (scientific, human) and the scientific title (Professor, Assistant Professor, Teacher, Assistant Lecturer). They were (144) university female

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 30 2010
Journal Name
Al-kindy College Medical Journal
Electron Microscopic Study of the Effects of Preeclampsia on the Placental Endothelial Cells Ultra Structures during Pregnancy
...Show More Authors

Background: Preeclampsia occurs in 3-5% of
pregnancies and is a major cause (12-20 %) of
maternal mortality in developed countries. It is the
leading cause of preterm birth and intra-uterine
growth restrictions (IUGR).
Objective: The study was designed to determine and
demonstrate the ultra structural changes of
endothelial cells in placenta of women suffering from
hypertensive disease.
Patients & Methods: Placental samples were
obtained from two groups of pregnant women
groups (preeclamptic and normal pregnant women).
The specimens were fixed in 2.5% gluteraldehyde
and preceded for electron microscopic examination.
Results: Placenta of women with preeclampsia has
shown marked degenerative

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of the strengths and weaknesses in Iraqi newspapers: The evolution of the consumer - the reader
...Show More Authors

The first section of this research discussed  the manner of the research from many sides like the problem it faces, importance of it , its targets ,boundaries, the way to collect and get information's and its assumption.

When the second chapter discussed the press – manufacturing and the development ,importance and types of newspapers, also its merits and weaknesses.

The third chapter talked about the scientific side and how to choose an assumption for the research . as it talked also about the apparent honest and stability tests that help in analyzing the research until getting results and so the right assumption for  the research will be chosen.

And finally, the fourth chapter put highlight on the be

... Show More
View Publication Preview PDF
Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Comparative Assessment of in Vitro Effect of Three Fluoride Releasing Agents on Enamel Demineralization around Orthodontic Brackets
...Show More Authors

View Publication
Crossref (2)
Crossref
Publication Date
Wed Oct 16 2019
Journal Name
Journal Of Research In Medical And Dental Science
Evaluation of the Antibacterial Efficacy of Silver Nanoparticles as an Irrigant against Enterococcus faecalis In vitro Study
...Show More Authors

Background: Successful root canal therapy depends on thorough chemo mechanical debridement of pulpal tissue, dentin debris and infective microorganisms. Objective: This study aimed to investigate the antibacterial effect of silver nanoparticles, sodium hypochlorite and chlorhexidine in reducing the bacterial infection of the root canals. Materials and Methods: The root canals of 55 single-rooted teeth were cleaned, shaped, and sterilized. All the teeth samples were inoculated with Enterococcus faecalis and incubated at 37°C for 2 weeks. Then, the teeth were divided into four groups. Group I (n=15): 100 ppm silver nanoparticles, Group II (n=15): 2.5 sodium hypochlorite, Group III (n=15): 2% chlorhexidine, IV (n=10): Normal saline as a contr

... Show More
Publication Date
Sat Sep 08 2018
Journal Name
International Journal Of Applied Pharmaceutics
PREPARATION AND CHARACTERIZATION OF LAFUTIDINE AS IMMEDIATE RELEASE ORAL STRIP USING DIFFERENT TYPE OF WATER-SOLUBLE POLYMER
...Show More Authors

Objective: The objective of the present study was to design and optimize oral fast dissolving film (OFDF) of practically insoluble drug lafutidine in order to enhance bioavailability and patient compliance especially for a geriatric and unconscious patient who are suffering from difficulty in swallowing.Methods: The films were prepared by a solvent casting method using low-grade hydroxyl propyl methyl cellulose (HPMC E5), polyvinyl alcohol (PVA), and sodium carboxymethyl cellulose (SCMC) as film forming polymers. Polyethylene glycol 400 (PEG400), propylene glycol (PG) and glycerin were used as a plasticizer to enhance the film forming properties of the polymer. Tween 80 (1% solution) and poloxamer407 were used as a surfactant, citri

... Show More
View Publication
Scopus (11)
Crossref (6)
Scopus Crossref
Publication Date
Fri May 01 2020
Journal Name
Iraqi Geological Journal
RESERVE ESTIMATION OF LATE MIOCENE INJANA CLAYSTONE BEDS FOR PORTLAND CEMENT AND BRICK INDUSTRY, MIDDLE OF IRAQ
...Show More Authors

View Publication Preview PDF
Crossref