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Anbar Journal of Engineering Sciences

مجلة الأنبار للعلوم الهندسية

ISSN: 19979428
Publisher: University of Anbar
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

AJES is a high-quality scientific journal devoted to fields of Engineering(Civil,Mechanical,Electrical,Renewable Energy,Environment,Water Resources,Chemical and Aerodynamics).
Two issues per year are published by college of Engineering University of Anbar.
It was started in 2007 for publishing papers in two languages (Arabic ad English).According to instructions of publishing by AJES.

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Mob.07809655472 - 07906222028
e-mail: anbarjournal@yahoo.com

Table of content: 2019 volume:7 issue:4

Article
Numerical Study on Hydrothermal Performance Factor Using Jet impingement and Nanofluid

Authors: Ibrahim K. Alabdaly a --- , M. A. Ahmed b*
Pages: 308-315
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Abstract

In this study, thermal-hydraulic performance of a confined slot jet impingement with Al2O3-water nanofluid has been numerically investigated over Reynolds number ranges of 100-1000. Two triangular ribs are mounted at a heated target wall; one rib located on the right side of the stagnation point and another one located on left side of the stagnation point. The governing momentum, continuity and energy equations in the body-fitted coordinates terms are solved using the finite volume method and determined iteratively based on SIMPLE algorithm. In this study, effects of Reynolds number, rib height and rib location on the thermal and flow characteristics have been displayed and discussed. Numerical results show an increase in the average Nusselt number and pressure drop when Reynolds number and rib height increases. In addition, the pressure drop and average Nusselt number increases with decrease the space between the stagnation point and rib. The maximum enhancement of the average Nusselt number is up to 39 % at Reynolds number of 1000, the rib height of 0.3, rib location of 2 and nanoparticles volume fraction of 4%. The best thermal-hydraulic performance of the impinging jet can be obtained when the rib height of 0.2 and rib location of 2 from the stagnation point with 4% nanoparticles volume fraction.


Article
Effect of Grooves Geometric Parameters on Hydraulic Thermal Performance of Circular Pipe Partially Filled with Metallic Foam

Authors: Obaid T. Fadhil, --- Hamdi E. Ahmed --- Wisam A. Salih
Pages: 316-325
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Abstract

The present paper addresses the numerical study of non-Darcy laminar forced convection flows in a pipe partially filled with grooved metallic foam attached in the inner pipe wall, which is subjected to a constant heat flux. Computations are carried out for nine different dimensions of grooves with different Reynolds numbers namely; (250 ≤ Re ≤ 2000) and their influences on the fluid flow and heat transfer are discussed. The governing and energy equations are solved using the finite volume method (FVM) with temperature-dependent water properties. The novelty of this work is developing of a new design for the metallic foam, which has not studied previously yet. It is observed that the two helical grooves with two pitches increase the Nu around 5.23% and decrease the pumping power nearly 12%. It is also showed a reduction in the amount of material required for manufacturing the heat exchanger, which leads to a decline in the weight of the system 8.29%.


Article
Numerical Investigation on the Thermal Performance of Double Pipe Heat Exchanger Using Different Shapes of Fins

Authors: Wissam H. Khalil --- Asaad K. Ali
Pages: 326-348
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Abstract

In this study, a numerical investigation on the thermo-hydraulic performance of the double pipe heat exchanger into heat transfer by different shapes of fins on the outer surface for the inner tube as extended surfaces. The inner and outer diameters of the inner pipe were (16.05 mm), (19.05 mm) respectively, and (34.1 mm), (38.1 mm) for the outer tube. The length of the heat exchanger was (1000 mm). Hot and cold water were used as the working fluid, where the hot water flows inside of the inner one in counter flow with the cold water which flows in the annulus. The inlet temperature for the hot water is (75 OC) while it is (30 OC) for the cold. The hot fluid flows at constant rate which is (0.1kg/s) while the cold is varied from (0.1 kg/s to 0.2 kg/s).The study was perform using the known commercial CFD package (ANSYS – FLUNET 15) .The results shows that both (rectangular and triangular) fins enhances the heat transfer coefficient compare with the conventional plain tube .The rectangular fins presents an heat transfer enhancement ratio of (61% to 74%). Using of extended surfaces present a good result in saving energy by enhancing the performance of the double pipe heat exchangers used in petroleum industry.


Article
Investigation of human thermal comfort and improvement in public places adapted to a hot climate in Iraq

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Abstract

This study focuses on improving the thermal comfort in Mosques in Iraq. Omar bin Abdul Aziz Mosque in Baghdad is taken as a case study. In general, the weather in Baghdad is hot- dry climate during the summer. the study was conducted at the time of noon prayer on Friday where the maximum number of people can be obtained inside the Mosque about 500 worshipers and severe environmental conditions. Numerical methods (CFD) are used for the simulation utilizing the package of ANSYS (FLUENT V. 18). As the results depending on the number of elements, 4 millions elements are used for dividing the physical domain. Thermal comfort was assessed by finding the values of the predicted mean vote (PMV), predicted percentage of dissatisfied (PPD), and ASHRAE standard-55. The adaptive redistribution of the air conditioning device strategy at five cases is used to obtain the best thermal comfort. Moreover, changing the angle of air intake of space by changing the angle inclination of the access blade at three different angles of 0o, 7.5o and 15o degree, and studying its effect on the thermal comfort in breathing level. The four case is the best in terms of thermal comfort when the angle of intake air at 0o.when the PMV was 0.35 and PPD is 7.5, which is lower than the original state. The improving percentage of PPD is 10 % and PMV 14 %.


Article
Evaluation of Overall Resource Effectiveness for Job Shop Production System

Authors: Anat Amer Khudairb --- Lamyaa Mohammed Dawood
Pages: 362-371
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Abstract

ORE addresses various kinds of losses associated with manufacturing system which can be targeted for initiating improvements. Evaluating ORE will is helpful to the decision maker(s) for further analysis and continually improves the performance of the resources. Overall Resource Effectiveness (ORE) encompasses seven factors are; performance, quality rate, readiness, changeover efficiency, availability of material and availability of manpower. In this research Job shop production of General Company for hydraulic industries, with focus on Damper and Tasks Factory (DTF)is tested as a case study for two of the most customer demand rear dampers (Samaned and Nissan). Data are collected and analyzed for years 2016-2017 to evaluate of ORE values. Results show that process performance factor among other seven factors have the less value causing the highest loss in ORE decrease. Where the highest ORE value is (58.6%) for Nissan and (69.3) for Samaned rare production. Also, time loss due to set up time is detected where it ranges from 3% to about 13% per month for the above mentioned two tested dampers. Results are generated employing Minitab Version 17, Quality Companion Version 3 soft wares. It is recommended to introduce SMED (Single Minute Exchange of Dies) concept that could decrease losses in set up time .Also improvements in maintenance programs are vital, and above all improving process performance values is essential by employing lean manufacturing that result in fast outcomes ,and TQM process improvement strategy for long term outcomes these two process performance strategies may enhance ORE values therefore, decrease losses, and consequently increase quality and productivity.


Article
Modify the Performance of Electrical Transformer by Analysis Oil Aged and Paper Insulation with Nanoparticales

Authors: Dr. Sahar R. Al-Sakini
Pages: 372-381
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Abstract

A gradual change in the state and properties of the oil transformer due to aging, which generally leads to break down. Aging of the mineral oil cause permanent harmful change of the ability insulation system. Aging of the mineral oil and water content of paper insulation are simulated at the laboratory by putting the samples of the oil and pieces of insulation paper in a rig (transformer manufactured) and exposed to different temperatures (20Co, 40Co, 60Co, 80Co) for specific durations of time to analysis and improve the performance of the transformer. In this research, the electrical and physical characteristics for the mineral oil and paper insulation have been studied and then repeated by the addition of different concentration of Nanoparticales (ZnO) (0.01, 0.03, 0.05, 0.07)gm/ml then compared with the electrical properties of the pure mineral oil and paper insulation without (ZnO) nanoparticales


Article
Effect of Paving Runway and Atmospheric Conditions on Airplane Takeoff Distance and Time

Authors: Muhammad. A.R Yass
Pages: 382-392
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Abstract

This paper study the effect of paving runway and atmospheric conditions on airplane takeoff distance and time with roll stage and air stage. Two airplane types DC-9 and Boeing 747-400 were considered for different atmospheric condition with different weight by using time step integration technique and Krenkel and Salzman assumed that the variation of thrust and velocity create the balance of forces equations on the aircraft during its takeoff run. The air temperature and airplane weight and runway paving are the most effected parameters on takeoff time and distance. The runway paving consideration are very important for airport design and runway construction to minimums fuel consumption during takeoff


Article
Dynamic Response of a Cracked Composite Beam subjected to moving Load

Authors: Nazhad Ahmad Hussein
Pages: 393-398
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Abstract

The forced deflections of simply supported cracked composite beams are investigated when subjected to moving dynamic load. The crack is modeled as rotational spring and used in the formulation of the composite beam with a moving load in sinusoid wave. The numerical solution is satisfactory compared to the experimental results. The effects of crack depth and crack positions at different load speed are studied. The results show that the forced deflection increased with increasing the speed ratio and crack depth.


Article
Decision Making in Materials Selection: an Integrated Approach with AHP

Authors: Sattar A. Mutlag --- hamad M. hasan
Pages: 399-407
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Abstract

Materials selection is a multi-criteria decision-making (MCDM) problems because the large number of factors affecting on decision making. The best choice of available material is critical to the competitiveness and success of the manufacturing organisation. The analytical hierarchy process (AHP) is an important tool to solve MCDM problems. The choosing process of suitable material (such as a refrigerant fluid) for the Air Condition System (ACS) is faced with challenges such as lack of a systematic approach in setting the optimal performance in terms of its impact on the environment and operation. Selecting process for the one refrigerant from a range suitable of suitable refrigerant is complex process. The study presents a comparative performance analysis of ACS for using four alternative refrigerants R290, R410, R404 and R22. Then, one of these suitable refrigerant is selected. The comparison is based on three criteria system operation, environment and maintenance. Novels ACS performance assessment model is proposed based on an analytical hierarchy process (AHP). The model is based on two main criteria of ACS, quantitative criteria, cooling capacity (CC), coefficient of performance (COP), etc.). And qualitative criteria (Ozone Depletion Potential (ODP), Global Warming Potential (GWP) and maintenance cost (MC)). It is necessary to look for new technique help decision making to select alternative refrigerants, to fulfill the goals of the international protocols (Montreal and Kyoto) and optimum operation, to satisfy the growing worldwide demand, in addition the increase outdoor temperature in some countries. This study provides a developed methodology for evaluating ACS performance. Moreover, it helps to select a robust decision. The results obtained from AHP process that the best rank of the suitable refrigerant was R404 (0.3763) followed by R22 (0.3657) and so on for the other. Therefore, the proposed methodology can help the decision maker to select the best alternative for both criteria (qualitative and quantitative) in complex selecting process.


Article
Static analysis of two-directional functionally graded cylindrical panels under the effect of symmetric loads using finite element method (FEM)

Authors: Hamad M. Hasan --- Qutaibah M. Mohammed
Pages: 408-424
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Abstract

This paper offers the linear analysis of the static behavior of two directional functionally graded (2D-FG) cylindrical panels under the effect of internal symmetric loads. The mechanical properties of the cylindrical panel are given to be changed simultaneously through the thickness and longitudinal directions as a function to the volume fraction of the constituents by a simple power-law distribution. Based on Sander’s first order shear deformation shell theory (FSDT), the equations of motion for (2D-FG) panels are derived using the principle of minimum total potential energy (MPE). The finite element method (FEM) as an effective numerical tool is utilized to solve the equations of motion. The model has been compared with those available in the literature and it observed good correspondence. The influences of the material variation along the thickness and longitudinal directions, geometrical parameters, boundary conditions and load parameters on the panel deformation are studied in detail.

Table of content: volume:7 issue:4