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The Effects of Inclination and Compounds Angles of Round Holes in Staggered Rows on Adiabatic Film Cooling Effectiveness of Vane Suction side
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The aim of this work is oriented to increase film cooling effectiveness value through numerical investigations for flow of Mach number not more than 0.3 around vane surface, to find the effects of inclination and compounds angles of round holes in staggered rows on adiabatic film cooling effectiveness of vane suction side. Multi cylindrical film cooling hole cases were studied with pitch ratio P/d =2 and 3, local blowing ratios M=0.382, 0.77 and 1.14,  inclination angles a=30° and 45°, compound angles β= 0°, 15°, 30° and 45° and local momentum ratios I= 0.084, 0.34 and 0.756  for better cooling process.

            A numerical technique, using ANSYS-FLUENT version 14.5, was used to solve governing partial differential equations of mass, momentum (Navier Stokes equations) and energy conservations in three dimensions with a  turbulence model that involves the solution of the four transport equations. Based on the results of the numerical solution, the best film cooling configuration, blowing ratio, with the range of actual engine flow conditions, dimensions and vane geometry; density ratio 1.74 , temperature ratio 0.57 and blowing ratio M=0.382, 0.77 and 1.14 was obtained. The best case for inclination angle a=30°, P/d=2 was at M=1.14 and β=0° for the total average effectiveness along 60L/d of surface suction side was 0.616, while the best case for inclination angle a=45°, P/d=2 was at M=0.382 and β=30° for the total average effectiveness along 60L/d of surface suction side was 0.516.

            In addition, comparisons were performed with available other work, where the experimental total average effectiveness results of Dees et al., 2011 were in good agreements with the numerical results of current work with a maximum deviation of 9.9% at I=0.34 and 3.6% at I=0.75.

 

 

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Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
Iconography of Textual Thresholds in Crime Film Scenarios
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It is not new to say that recent studies have tended to look at the margins of the texts in order to extract the information provided by the book to the recipient. The margins of the texts were defined in a number of terms, including the thresholds, and the margins of the text, etc. The difference was according to the researchers who dealt with the subject in research and inquiry. Therefore, all researchers assert that the texts must provide information even if it is propaganda for the text. Hence the importance of these texts emerged as they represent a scientific information material that encapsulates the body of the text as well as being a propaganda material that inspires the reader to read it. Hence for

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Effect of the Dielectric Barrier Discharge Plasma on the Optical Properties of CDS Thin Film
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Cadmium sulphide CdS films with 200 nm have been prepared by thermal evaporation technique on glass substrate at substrate room temperature under vacuum of 10-5mbar.In this paper, the effect of Dielectric Barrier Discharge plasma on the optical properties of the CdS film. The prepared films were exposed to different time intervals (0, 3, 5, 8) min. For every sample, the Absorption A, absorption coefficient α , energy gap Eg ,extinction coefficient K and dielectric constant ε were studied. It is found that the energy gap were decreased with exposure time, and absorption , Absorption coefficient, refractive index, extinction coefficient,  dielectric constant increased with time of exposure to the plasma. Our study conside

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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
Cooling and Heating a Greenhouse in Baghdad by a Solar Assisted Desiccant System
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Modeling the microclimate of a greenhouse located in Baghdad under its weather conditions to calculate the heating and cooling loads by computer simulation. Solar collectors with a V-corrugated absorber plate and an auxiliary heat source were used as a heating system. A rotary silica gel desiccant dehumidifier, a sensible heat exchanger, and an evaporative cooler were added to the collectors to form an open-cycle solar assisted desiccant cooling system. A dynamic model was adopted to predict the inside air and the soil surface temperatures of the greenhouse. These temperatures are used to predict the greenhouse heating and cooling loads through an energy balance method which takes into account the soil heat gain. This is not included in

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Publication Date
Tue Sep 01 2020
Journal Name
Journal Of Engineering
Buckling Behavior of Aluminum Alloy Thin-Walled Beam with Holes under Compression Loading
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Thin-walled members are increasingly used in structural applications, especially in light structures like in constructions and aircraft structures because of their high strength-to-weight ratio. Perforations are often made on these structures for reducing weight and to facilitate the services and maintenance works like in aircraft wing ribs. This type of structures suffers from buckling phenomena due to its dimensions, and this suffering increases with the presence of holes in it. This study investigated experimentally and numerically the buckling behavior of aluminum alloy 6061-O thin-walled lipped channel beam with specific holes subjected to compression load. A nonlinear finite elements analysis was used to obtain the

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Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Teaching Practices of Science and Mathematics Teachers Based on the National Framework for Future Skills in the Omani School
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Abstract

The research aims to identify the level of effectiveness of the teaching practices of science and mathematics teachers in light of the national framework for future skills in Omani schools. To achieve the objectives of the study, the researchers used the descriptive approach, as he designed a note card consisting of (30) phrases distributed on three axes: basic skills, practical skills, and technical skills. After verifying the validity and reliability of the tools, they were applied to a sample of (116) teachers. The results of the research revealed that the level of effectiveness of the teaching practices of mathematics teachers has recorded a medium degree with a mean (3.05). The results a

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Publication Date
Fri Aug 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
The impact of strategic approach in the effectiveness of small and medium Enterprises in Iraq
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The purpose of this research highlight the achievement of the effectiveness of small and medium enterprises dimensions and conformable to analyze the relationship between business strategies and human resources management strategies , and launched search of a dilemma thought provoking fundamental questions revolve around the search is the lack of appropriate strategies in these enterprises to help them continuity and permanence in business and markets , as these enterprises lack the human resources management strategies appropriate , as well as business strategies that make them withstand the changes in the market environment is changing and volatile . It was to

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Publication Date
Sun Jul 31 2022
Journal Name
Journal Of Ovonic Research
Effect of annealing on thin film AgInSe2 solar cell
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AgInSe2 (AIS) thin films solar cell involving of n-type AgInSe2 and Si of p-type substrate by using thermal evaporation method. The influence of annealing of the preparation AgInSe2 were considered to find the best properties of solar device. Thin film AIS have been deposited under the vacuum of 1.5*10-6 Torr with (400) nm thickness at R.T and annealing temperatures (473,573) K. Polycrystalline tetragonal structure for AIS thin films from XRD and increasing of surface roughness from AFM, energy gap values decreasing with increasing annealing temperatures, all films were negative type, I-V characteristics show increasing of efficiency with increasing of annealing temperatures.

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Publication Date
Tue Oct 01 2024
Journal Name
Renewable And Sustainable Energy Reviews
A critical review on the efficient cooling strategy of batteries of electric vehicles: Advances, challenges, future perspectives
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Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Freedom of movement of capital and its impact on the effectiveness of monetary policy In Iraq (2005-2016)
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The interest in the issue of capital movement as an economic phenomenon has increased because of its effects and effects and its ability to influence the economic balance and the effectiveness of monetary policy. All countries seek to attract capital and benefit from it because of its effects and results such as supporting economic development process and optimal allocation of economic resources. The problem of the financing gap that most countries suffer from, and others, but sometimes the movement of capital creates challenges for monetary policy makers in achieving their goals.

   After 2003, the Iraqi economy witnessed an openness and economic liberalization unlike previous years, which

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Publication Date
Sat Mar 30 2024
Journal Name
Al-qadisiyah Journal For Engineering Sciences
Investigation of an automobile air-conditioner with a liquid-suction heat exchanger using R134a and R1234yf
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Air-conditioning systems (ACs) are essential in hot and humid climates to ensure acceptable ambient air quality as well as thermal comfort for buildings users. It is essential to improve refrigeration system performance without increasing the effects of global warming potential (GWP) and ozone depletion potential (ODP). The main objective of this study is to evaluate the performance of an air conditioning system that operates with a liquid suction heat exchanger (LSHX) through implementing refrigerants with zero OPD and low GWP (i.e., R134a and R1234yf). Liquid suction heat exchanger (LSHX) was added to an automobile air conditioning system (AACS).When Liquid suction heat exchanger was added to the cycle, primary results indicated t

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