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Numerical Investigation of Aerodynamic Characteristics of Supercritical RAE2822 Airfoil with Gurney Flap
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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. 

 

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
phylogentic study of cephalopharyngeal selerites
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drosophila larvare of diffrent speces were subjected to this in order study the structure of cephalopharyngeal armature and mouth more hooks dentition the lines number among

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Publication Date
Tue Jul 31 2018
Journal Name
العلوم السياسية
Legal regulation of electronic contracting
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The use of legislation related to electronic contracting, through the adoption of the method of enactment of legislation and legislative intervention, and to be careful and cautious in the issuance of legislative texts that do not adversely affect the business activity, which is taking its steps for the first time on the path of electronic commerce in this new world by the new knowledge of the subject theoretically and practically , With the necessary assistance of legal expertise so that legislation does not constitute barriers and obstacles to the development of electronic commerce.

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Publication Date
Sun Oct 01 2023
Journal Name
Baghdad Science Journal
Biological peculiarities of Leucozonella retteri
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The aim of the research is to study the biology, life cycles, distribution and structure of the reproductive organ of Leucozonella retteri in natural conditions. Zoological and malacological methods are used in the work. The collection of the material was carried out according to A.A. Shileiko method. According to the results of the conducted studies, the differences between Leucozonella retteri and other species in the structure of the reproductive organ were manifested in the following. The lower part of the sperm is straight, the ovary is slightly curved. The paw pad is 8, located in 4x2 positions. The stylophore is large spherical. The vagina is cylindrical, its length is 5-6 times greater than the width. The penis is large and conve

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Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Kinetic Study of Esterification Reaction
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The Esterification kinetics of acetic acid with ethanol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 50-60°C and at a different molar ratio of ethanol to acetic acid [EtOH/Ac]. Investigation of kinetics of the reaction indicated that the low of [EtOH/Ac] molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 80% was obtained at 60°C for molar ratio of 10 EtOH/Ac. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. Activity coefficients were calculated using UNIFAC progra

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Publication Date
Fri Jan 01 2010
Journal Name
Journal Of Collage Of Education
Some Generalizations of Continuity Functions
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In this paper we define and study new generalizations of continuous functions namely, -weakly (resp., w-closure, w-strongly) continuous and the main properties are studies: (a) If f : X®Y is w-weakly (resp., w-closure, w-strongly) continuous, then for any AÌX and any BÌY the restrictions fïA : A®Y and fB : f -1(B)®B are w-weakly (resp., w-closure, w-strongly) continuous. (b) Comparison between deferent forms of generalizations of continuous functions. (c) Relationship between compositions of deferent forms of generalizations of continuous functions. Moreover, we expanded the above generalizations and namely almost w-weakly (resp., w-closure, w-strongly) continuous functions and we state and prove several results concerning it.

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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Kufa Legal And Political Science
Civil Rights Protection of Minorities
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The protection of the rights of minorities is primarily an internal issue that depends on the nature of the political system of the state, and it is one of the internal means to reassure minorities and ensure their enjoyment of those rights. It can be a safety valve against the problems that these minorities may raise. that live in our society, but rather work on developing a legal system that can serve as a role model to protect our minorities, which contributed to drawing a picture that reflected the diversity of our society

Publication Date
Mon Jan 01 2024
Journal Name
Pakistan Journal Of Life And Social Sciences (pjlss)
Mental Durability of Postgraduate Students
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Publication Date
Wed Jun 01 2022
Journal Name
Political Sciences Journal
Radical democracy of Axel Honneth
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In contemporary discourses the debate of most Western thinkers is about the efforts to clarify the normative foundations of democracy. And then, some political thinkers have adopted other models differ in terms of standards for traditional liberal democracy. Be the common goal of democracy will give the formation of a greater role than usual in political liberalism rather than limiting the participatory activity of citizens on the function to give permanent legitimacy to the exercise of state authority. The activity is to be permanently enshrined in the democratic public sphere and the issue must be understood as the source of all political decisions.

 

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Publication Date
Tue Nov 20 2018
Journal Name
Infection And Immunity
Acknowledgment of ad hoc reviewers
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Publication Date
Fri Dec 06 2024
Journal Name
Indian Journal Of Entomology
Species of Chrysididae from Iraq
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A survey of chrysidid wasps and an identification key to the genera from different localities in Iraq are provided. The genus Pseudomalus Ashmead, 1902 with Pseudomalus auratus (Linnaeus) and Omalus timidus (Nurse), are new records from Iraq. As well, a preliminary checklist of Iraq’s Chrysididae is suggested. Twenty species within nine genera in two subfamilies have been included in the current list. Historical information is provided together with remarks on the current taxonomic status and the particular validity for some species.

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