The effect of internal acoustic excitation on the leading-edge, separated boundary layers and the aerodynamic performance of NACA23015 cross section airfoil are examined as a function of excitation location with ranging frequency range (50-400) Hz of the introduced acoustic. Tests are separately conducted in two sections, open type wind tunnels at the Reynolds number of 3.3x105 for measurement at angle of attack (0, 3, 6, 9 &12) deg. and 3x104 for the visualization at angle of attack (12) deg. based on the airfoil chord. Results indicated that the excitation frequency and the excitation location are the key parameters to alter the flow properties and thus to improve the aerodynamic performance. The most effective excitation frequency is found to be equal to the shear layer instability frequency and on excitation location close to the separation point. Moreover, the lift is increased and drag reduced dramatically. The corresponding boundary layers are visualized to be reattached to the surface.
Abstract
Knowing the amount of residual stresses and find technological solutions to minimize and control them during the production operation are an important task because great levels of deformation which occurs in single point incremental forming (SPIF), this induce highly non-uniform residual stresses. In this papera propose of a method for multilayer single point incremental forming with change in thickness of the top plate (0.5, 0.7, 0.9) mm and lubrication or material between two plates(polymer, grease, grease with graphite, mos2) to knowing an effect of this method and parameters on residual stresses for the bottom plates. Also compare these results for the
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The relationship between music and plastic arts can be viewed as an interdependent relationship, as they both develop imagination, focus and sensory perception, as well as the presence of some artistic concepts that music shares with the art of drawing, on this basis the rationale for this research aimed at identifying (the influence of music) was dealt with On the artistic output (drawing) of students of the Department of Art Education - College of Fine Arts) In the first chapter the problem of research, importance, terminology, boundaries and goal was addressed, and in the second chapter the researcher dealt with in the first topic the relationship between music and painting, and in the second topic the use of music in education. As fo
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Abstract
In the present work the effect of bearing compliance on the performance of high speed misaligned journal bearing lined with a compliant PTFE liner lubricated with bubbly oil at high speeds has been studied. The effect of induced oil film temperature due to shearing effect has been implemented. Hydrodynamic effect of the complaint bearing and the influence of aerated oil have been examined by the classical thermohydrodynamic lubrication theory modified to include the effect of oil film turbulence and oil film temperature with suitable models for bubbly oil viscosity and density. The effect of liner elastic deformation has been implemented by using Winkler model. The effects of variable density and s
... Show MoreThe Islamic Bank of Al-Nahrain offers a formula for financing the purchase of real estate through a deferred sale contract, through Murabaha to the order to buy, and the payment of the price is in the form of instalments that include (the purchase price of the profit and the mutual agreement on the real estate). This research aims to show the reflection of real estate murabaha on the bank's investments, by measuring the effect of real estate murabaha on the profits achieved by the Islamic Bank of Al-Nahrain Bank. The growth of 'real estate murabaha' realized from the 'amounts granted by Bank X, in addition to analyzing the financial ratios of profitability indicators, including (return on deposits Y2) and for the years (2016 - 20
... Show MoreReceipt date: 8/8/2020 acceptance date: 9/11/2020 Publication date: 31/12/2021
This work is licensed under a Creative Commons Attribution 4.0 International License.
The American-Iranian relations have been characterized by tensions since the arrival of the guardian jurist regime in Iran to leadership in 1979, as it was considered a turning point not only in the cont
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Abstract
The research seeks to shed light on green accounting information systems, analyze them, identify sustainability reporting and how to improve it, as well as study the importance of the Iraqi oil sector, analyze it, and work on applying green accounting information systems in order to improve the quality of sustainability reporting. Oil as a branch of the General Corporation for the Distribution of Oil and Gas Products to apply the practical aspect and prove the hypothesis of the research. Explaining the company's role in improving environmental conditions
The research aims to study the effect of an increase in funding the Equity by issuing new common shares on revenues ordinary shares, despite the issuance and marketing costs and the introduction of new shareholders that companies incur when issuing new common shares but it is the most important methods used to finance the Equity is funding the common shares it provides money sufficient to finance the large investments of the company and enhance the confidence of dealers with the company, so I designed this research in order to identify the impact of increased funding Equity issue new common shares to common shares revenues.
This research has included some of the theoretical concepts to each of the Equity
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Crime is considered as an unlawful activity of all kinds and it is punished by law. Crimes have an impact on a society's quality of life and economic development. With a large rise in crime globally, there is a necessity to analyze crime data to bring down the rate of crime. This encourages the police and people to occupy the required measures and more effectively restricting the crimes. The purpose of this research is to develop predictive models that can aid in crime pattern analysis and thus support the Boston department's crime prevention efforts. The geographical location factor has been adopted in our model, and this is due to its being an influential factor in several situations, whether it is traveling to a specific area or livin
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In this work we run simulation of gas dynamic problems to study the effects of Riemann
problems on the physical properties for this gas.
We studied a normal shock wave travels at a high speed through a medium (shock tube). This
would cause discontinuous change in the characteristics of the medium, such as rapid rise in
velocity, pressure, and density of the flow.
When a shock wave passes through the medium, the total energy is preserved but the energy
which can be extracted as work decreases and entropy increases.
The shock tube is initially divided into a driver and a driven section by a diaphragm. The
shock wave is created by increasing the pressure in the driver section until the diaphragm bursts,
se
This study included the effect of chronic exposure of different concentrations of sodium chloride on the freshwater Crustacean Daphinea pulex from the order of Cladocera. The concentrations used for the chronic exposure were( 0.1‰, 0.5‰, 1‰, 1.5‰, 2‰ )to investigate the effect on the some reproductive parameter which included mean number of eggs and juveniles produced per female and per clutch,and mean number of clutch per female which decline from (6.0) clutch/female in the control treatment to (3.0) clutch/female in (2‰) concentrations, as well as to investigate the number of females produce the clutches and we found only one female produced six cluthes in the( 2‰) concentration of sodium chlor
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