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Aerodynamic Characteristics of CLARK-Y Smoothed Inverted Wing with Ground Effects
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A two-dimensional computational study had been performed regarding aerodynamic forces and pressures affecting a cambered inverted airfoil, CLARK-Y smoothed with ground effects by solving the Reynolds-averaged Navier-Stokes equations, using the commercial software COMSOL Multiphysics 5.0 solver. Turbulence effects are modeled using the Menter shear-stress transport (SST) two-equation model. The negative lift (down-force), drag forces and pressures surface were predicted through the simulation of wings over inverted wings in different parameters namely; varying incidences i.e. angles of attack of the airfoils, varying the ride hide from the ground covering various force regions, two-dimensional cross-section of the inverted front wings to be fixed on nose of a race car- and varying speeds of initial airflow (Reynolds number). The results show that the down-force increases as the angle of attack increases; however, if an inverted wing is fixed on a car at high angles of attack the wing starts to stall which is not a desired condition that affects the vehicle stability and performance. As the ride height was reduced, the down-force was increased; at clearances between the suction surface and the ground of less than 0.2 of the chord length c, the down-force is significantly higher. Very close to the ground, at a ride height of less than 0.1c, down-force decreases as the wing stalls. Also, down-force increases as the free-stream velocity (Reynolds number) increases. The pressures for lower and upper surface of the wing increased with increasing both of angle of attack and ride height, but remains relatively ineffective with varying the speeds.

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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
The Effect of Laminated Layers on the Flutter Speed of Composite Wing
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The paper presents an investigation to the flutter speed of composite wing for different ply orientation. Structurally the composite wing was idealized as a composite beam load carrying structure. Theodorsen’s expression was used to get the 2- dimension unsteady lifting force and pitching moment in the limit of incompressible flow and subsonic speed which were integrated over the wing span. A free vibration analysis was first carried out to get the natural frequencies and mode shapes .The velocity-damping (V-g) method was used to calculate the flutter speed and the flutter frequency. A wing of unmanned aerial vehicle was manufactured from woven glass and polyester resin where the flutter speed was calculated experimentally by the wind

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Publication Date
Sat Jan 01 2005
Journal Name
Journal Of The College Of Languages (jcl)
Ser y Estar
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Ser y Estar

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Publication Date
Sun Mar 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Numerical Computations of Transonic Critical Aerodynamic Behavior of a Realistic Artillery Projectile
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The determination of aerodynamic coefficients by shell designers is a critical step in the development of any projectile design. Of particular interest is the determination of the aerodynamic coefficients at transonic speeds. It is in this speed regime that the critical aerodynamic behavior occurs and a rapid change in the aerodynamic coefficients is observed. Two-dimensional, transonic, flow field computations over projectiles have been made using Euler equations which were used for solution with no special treatment required. In this work a solution algorithm is based on finite difference MacCormack’s technique for solving mixed subsonic-supersonic flow problem. Details of the asymmetrically located shock waves on the projectiles hav

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Publication Date
Sun Mar 17 2019
Journal Name
Baghdad Science Journal
Study of Aerodynamic Surface Roughness for Baghdad City Using Signal-Level Measurements
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Roughness length is one of the key variables in micrometeorological studies and environmental studies in regards to describing development of cities and urban environments. By utilizing the three dimensions ultrasonic anemometer installed at Mustansiriyah university, we determined the rate of the height of the rough elements (trees, buildings and bridges) to the surrounding area of the university for a radius of 1 km. After this, we calculated the zero-plane displacement length of eight sections and calculated the length of surface roughness. The results proved that the ranges of the variables above are ZH (9.2-13.8) m, Zd (4.3-8.1) m and Zo (0.24-0.48) m.

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Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
The effects of silica addition on the structural, electrical and mechanical characteristics of MgAl2O4 spinel ceramic phase
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The ceramic compound Mg1-xSixAl2O4 (x= 0, 0.1, 0.2, 0.3, 0.4) was prepared from nano powder of Al2O3 and MgO doped with Nano powder of SiO2 at different molar ratios. The specimens were prepared by standard chemical solid reaction technique and sintered at 1450 oC. Structure of the specimens was analyzed by using X-ray diffraction (XRD). The X-ray patterns of the specimens showed the formation of pure simple cubic spinel structure MgAl2O4 phase with space group of ̅ . The average grain size and surface topology were studied by atomic force microscopy. The results showed that the average grain size was about 73-90 nm. The DC electrical properties of the specimen were measured. The apparent density was found to increase and the porosity a

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Publication Date
Sun Jun 11 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
An Efficient Single Stage Shrinkage Estimator for the Scale parameter of Inverted Gamma Distribution
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 The present  paper agrees  with estimation of scale parameter θ of the Inverted Gamma (IG) Distribution when the shape parameter α is known (α=1), bypreliminarytestsinglestage shrinkage estimators using  suitable  shrinkage weight factor and region.  The expressions for the Bias, Mean Squared Error [MSE] for the proposed estimators are derived. Comparisons between the considered estimator with the usual estimator (MLE) and with the existing estimator  are performed .The results are presented in attached tables.

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Publication Date
Sun Feb 01 2015
Journal Name
Italian Journal Of Geosciences
Characteristics of Clays Stabilized with Lime-Silica Fume Mix
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Publication Date
Thu Jul 01 1999
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
new species of ground beetles (Coleptera : Carabidae) from Iraq
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Among a collection of ground beetles from Iraq the new species Acinopus euphraticus was designated and described here. The erection of this new species was mainly built on external features and the description of male genitalia.

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Publication Date
Sat Apr 01 2023
Journal Name
Physics Of Atomic Nuclei
Differences in Ground State Properties of Some Mirror Nuclei
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Publication Date
Mon Jan 01 2018
Journal Name
Journal Of The College Of Languages (jcl)
LA METÁFORA, LA METONIMIA Y OTROS FENÓMENOS RETÓRICOS EN LENGUA ÁRABE Y ESPAÑOLA
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Resumen:

En este artículo se indaga sobre fenómenos como la metáfora, la metonimia, la polisemia, y la homonimia en las lenguas árabe y española, según la teoría cognitiva, basada en el pensamiento y la práctica lingüística. Esta teoría intenta investigar la relación entre el lenguaje humano, la mente y la experiencia. En realidad, los fenómenos que estudiaremos crean ambigüedad léxica y sintáctica tanto en árabe como en español. Además, dichos conceptos tienen sus propias características, especificaciones y formas en cada lengua.
Abstract:

This article studies phenomena such as metaphor, metonymy, polysemy, homonymy in Arabic and Spanish, according to cognitive theory, based on linguistic thought a

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