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
Sat Mar 01 2008
Journal Name
The Third International Conference On Mathematical Sciences
On Solvability of an Operator Equation
...Show More Authors

Publication Date
Sun Oct 03 2021
Journal Name
Al-manhaj
Fundamentals of Financial Statistics- (Third Edition)
...Show More Authors

This Book is intended to be a textbook studied for undergraduate course in financial statistics/ department of Financial Sciences and Banking. This book is designed to be used in semester system. To achieve the goals of the book, it is divided into the following chapters. Chapter one introduces basic concepts. Chapter two devotes to frequency distribution and data representation. Chapter three discusses central tendency measures (all types of means, mode, and median). Chapter four deals with dispersion Measures (standard deviation, variance, and coefficient of variation). Chapter five concerned with correlation and regression analysis. While chapter six concerned with testing Hypotheses (One population mean test, Two "independent" populati

... Show More
Preview PDF
Publication Date
Fri Oct 11 2019
Journal Name
Journal Of The College Of Education For Women
The Symbolic Interaction of the Kindergarten
...Show More Authors

The Symbolic Interaction of the Kindergarten

View Publication Preview PDF
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Optical properties of CdO thin films
...Show More Authors

Cadmium Oxide thin films were deposited on glass substrate by spray pyrolysis technique at different temperatures (300,350,400, 500)oC. The optical properties of the films were studied in this work. The optical band-gap was determined from absorption spectra, it was found that the optical band-gap was within the range of (2.5-2.56)eV also width of localized states and another optical properties.

View Publication Preview PDF
Crossref
Publication Date
Mon Jun 01 2015
Journal Name
International Journal Of Advanced Research In Computer Science And Software Engineering
Performance Comparison of Transport Layer Protocols
...Show More Authors

Transport layer is responsible for delivering data to the appropriate application process on the host computers. The two most popular transport layer protocols are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). TCP is considered one of the most important protocols in the Internet. UDP is a minimal message-oriented Transport Layer protocol. In this paper we have compared the performance of TCP and UDP on the wired network. Network Simulator (NS2) has been used for performance Comparison since it is preferred by the networking research community. Constant bit rate (CBR) traffic used for both TCP and UDP protocols.

View Publication
Publication Date
Thu Sep 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Acid Treatment of Iraqi Paraffin Wax
...Show More Authors

View Publication Preview PDF
Publication Date
Tue Mar 28 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Antimicrobial Activity of Hydroxymatairesinol (HMR) Lignan
...Show More Authors

Lignans are natural products widely distributed in the plant kingdom. They are composed of two β-β-linked phenylpropane (shikimate-derived biogenetic subunits). Although the backbone of lignans is composed of phenylpropane units, there is enormous diversity in the structure of lignans leading to different classes of lignans, such as γ-butyrolactone derivatives, eg. Hymatairesinol, bicyclooctadiene derivatives, e.g. pinoresinol, tetrahydrofuran derivatives e.g.lariciresinol, di-arylbutandiol derivatives, e.g. secoisolariciresinol. Introduction of a further carbon –carbon linkage leads to a class of lignans collectively known as cyclolignans such as tetrahydro-naphthalene derivatives, for example podophyllotoxin. Lignans ha

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 02 2012
Journal Name
Baghdad Science Journal
Aquatic Oligochaetes of Iraq's Southern Marshes
...Show More Authors

Aquatic Oligochaetes community in the Iraqi southern marshes, Al- Hawiezah, Al-Chibayish and Al-Hammar, have been studied for the period from July 2006 to June 2007. Two sites within each marsh, in addition to a reference site located at Shatt Al-Garma, have been chosen for sample collection using Ekman dredge. The results revealed that the highest average annual density was 16800 individual / m2 recorded in Al-Hawiezah marsh, while in Al-Chibayish and al-Hammar marsh the density did not exceed 5111 individual/m2. In contrast, the density of Oligochaetes recorded in Shatt Al-Garma was about 10500 individual / m2. The highest monthly density was recorded in April 2007.The highest local percentage occurrence was 96% recorded in Al-Hawiezah ma

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
Enhance Similarity Measure of Ontologys' Concepts
...Show More Authors

The field of identification of similarity was considered a subject of research strongly recommended in the areas of semantic web, artificial intelligence and linguistic literature. In this paper a new similarity measure is proposed based on the Wu and Palmer measure. This measure is applied on the domain of the pedagogical ontology. Results obtained showed that the new measure gives better relevance of the similarity values compared to the approach of Wu and Palmer and it appears that the proposed measure is advantageous because obtained results showed that it is faster and capable of obtaining results to concepts not located in the same path.

View Publication
Publication Date
Tue Dec 30 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Management of facial fistulas and sinuses
...Show More Authors

Background: A major difference between the treatment of the skin lesions and the odontogenic and non-odontogenic sinuses. We aimed to analyze a substantial number of consecutive causes in order to clinical suspicion in the differential diagnoses may be correctly weighted. Materials and methods: The material of this research consisted of 40 patients. A complete history is collected from the patients with the duration and the site of the sinus present, the patient was examined for factors of the fistulas and sinuses and its associations, and patient having any concomitant lesions, a medical consultation done for opinion and management. Clinical examination with facial fistulas and sinuses was mandatory to avoid any mistakes that may occur. A

... Show More
View Publication Preview PDF