Table of content

Iraqi journal of mechanical and material engineering

المجلة العراقية للهندسة الميكانيكية وهندسة المواد

ISSN: 20761819
Publisher: Babylon University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

Iraqi journal for mechanical and material engineering is a refereed scientific journal published quarterly by the engineering college/ university of Babylon. It deals with high quality researches in fields of mechanical and material engineering.

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Contact info

Journal E-mail:
j.mec_mat_eng@yahoo.com
Babylon university/Babylon/Iraq P.O.Box(4)
Tel:++96430245387.(1155)

Table of content: 2010 volume:10 issue:1

Article
Numerical Prediction of Free Convection Phenomena Througha Rectangular Inclined Cavity Filled with a Porous Media.
التخمين العددي لظاهرة الحمل الحر خلال فجوة مائلة مستطيلة الشكل مملوءة بوسط مسامي.

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Abstract

1. Abstract: Numerical simulation of free convection air flow through a porous media in an inclined rectangular cavity is studied.Physical problem consists of a rectangular inclined cavity filled with a porous media.The top and bottom surfaces are thermally insulated while the left and right walls are maintained at isothermal hot and cold temperatures respectively.The two-dimensional flow is characterized using Under-Relaxation finite difference scheme.It is found that the two-dimensional flow is characterized by the vortices that are initiated by the existance of buoyancy effect.The problem considered deals with a two-dimensional internal, laminer , isothermal flow in an inclined rectangular porous cavity. In this work, the Darcy model is used and the governing equations are solved using Under-Relaxation explicit technique for flow characterstics of Prandtl number at 0.7 , an aspect ratio equals to 1.5, Rayleigh number ranging 50 and 100, and inclination angles of 30o , 50o and 90o respectively.The results explain that the flow field is dominated by one cell rotating in a clockwise direction and filling the cavity. Also,the variation of the average Nusselt number with inclination angles is also presented.The results showed a good agreement with other published results.


Article
Fluid-Particle Flow in Deeming of Inertia-Air Filter Design
جريان المائع و الجسيم في تصميم فلترالهواء العامل بمبدأ القصور الذاتي

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Abstract

The usage of inertia air filter to clean air passing to air consuming device has few attention in spite of its importance .This work focuses on the idea and advantages beyond this filter .A finite element solution of Navier- stoke equation in turbulent Zone is used to obtain pressure and velocity distribution through typical section in inertia air filter, these values are used to obtained the trajectory of different particle size using four order Runge-kutta integration method .The path trajectory will device on how large particles size can enter certain zone. Inertia air filter will prevent the air consuming devices from stopping due to blocked air filter .A special design is proposed so that to minimize loss with good ability in filtering dusty air .The usage of inertia air filter will help in elongate the life time of the usual air filter without appreciable increasing in pressure loss.

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Article
مقارنة الاداء للتوربينات الريحيه عموديه المحور رباعية الريش مع ثنائيه الريش

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Abstract

Abstract: The wind turbine performance test has high aspect on wind energy utilization. Present work wind tunnel testing of Savanious rotor performance with four blades. Results compared with well-known wind turbine Savnious of two blades. Savanious rotor models are manufactured in Industrial Engineering Company. The subsonic wind turbine had been calibrated before the test. The rotting speed and torque generated one turbine shaft are reported. Powers, power coefficient, tip speed ratio and Rynolds number are calculated. Results show that Savanious rotor with two blades gives good performances compared with four blades rotor.


Article
Free Vibration of Curved Beam with Varying Curvature and Taper Ratio
الاهتزاز الحر لعتبة منحنية بتغير التكور ونسبة السمك

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Abstract

In this study free vibration of uniform curved beam with varying curvature and taper thickness between the root and tip of beam are investigated by using the finite element method using Ansys(9.0). nine models from curved beam all models have four cases have different in taper ratio for the same curvature are studied. The results obtained from this study are compared with the results of other investigators in existing literature for the fundamental natural frequency and its found from this results the natural frequency increase with increasing the taper ratio and curvature for the servel models from curved beams. Finally the effect of the taper ratio and curvature on the natural frequency are shown in graphics.

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Article
Experimental and Analytical Study of Tensile Properties For Hyper Composite Material

Authors: Ali S. Humod Muhannad Al-Waily
Pages: 58-69
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Abstract

In this work, an experimental and analytical solution for tensile properties of hyper composite material is presented. The composite material consist of composite matrix, bounded from resin material and short fiber, and long reinforcement fiber. The result for the tensile properties of composite material combined from composite matrix and reinforcement fiber, E1, E2, G12, and 12. In addition, the results showing the effect of volume fraction of short and long fiber, and the types of short and long fiber reinforcement, presented by analytical solution. And, the yield stress of hyper composite material is defined by experimental study with various of volume fraction of resin, short fiber, and long fiber.

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Article
Preparation of the surface of used cylindrical steel cases for zinc recoating

Authors: Abdulrasoul Salih Altaei
Pages: 70-76
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Abstract

Used cylindrical steel case usually plated with zinc, to reuse these cases, dirt, oil, grease, rust and old layer of zinc coat must be removed and again replated. In an mechanical complex, cleaning and surface preparation of used steel case was carried by mechanical method. Sanding lathe machines with an emery sandpapers were used to do this job, this method has many disadvantages, some of are the low production rate , the need for large manpower , original metal damage , it is expensive and dust occur during sandering cause environmental problems at the jobsite. In this case study cheap, and high production rate chemical method was proposed and executed to clean and prepare steel case surface for recoating as alternative to the mechanical method, the production rate increased more than ten fold compared with mechanical method. . The concentration of the consistent of the chemical solutions and operation conditions were determined as a result of several experiments. Eight steps technological procedure was suggested.

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Article
Mechanical Properties Investigation of HDPE Matrix Composites Reinforced with Wheat Straw Fibers
دراسة الخواص الميكانيكية للمواد المركبة المتكونة من البولي اثلين عالي الكثافة كأساس مع قش الحنطة كألياف تقوية .

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Abstract

The present article summarizes an experimental study on the mechanical behavior of high density polyethlene (HDPE)/ wheat straw (WS) composites. The mean goals of this investigation were using of wheat straw (WS) as a filler (reinforcer), effectiveness of straw flour fiber with different size (10-30 mesh as fine) and (30-50 mesh as coarse) on mechanical properties of composites and effect of maleic anhydride (MA) as a coupling agent treatment is performed to improve interfacial adhesion between the fibers and HDPE matrix. Generally, (16) treatment were conducted as (8) treatment of HDPE with 10, 20, 30, 40% coarse wheat straw with (0.5, 1.0, 1.5, 2.0) MA, 8 treatment of (HDPE) with 10, 20, 30, 40% fine wheat straw (WS) with (0.5, 1.0, 1.5, 2.0) MA, (HDPE) (WS). This study focused upon tensile strength, flexural, impact strength and hardness of reinforced polyethylene. The results showed that increase wheat straw rate to 30% in both fine and coarse, improved [tensile, strength hardness flexural and impact strength] values, Fine (WS) particles sample showed better, then coarse (WS) when addition for HDPE as fiber to produced composite material.The optimum formulation for the (HDPE and WS) composites on the mechanical properting is (30wt.%WS as fine-HDPE-1.5wt.%MA).

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Article
Effect of Heat Treatments on Thermal Conductivity and Mechanical

Authors: Dr. Alaa A. Ateia
Pages: 88-96
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Abstract

An automotive brake rotor material has noticeable properties where, the gray cast iron is superior for that application. In this work, a detailed description of the process of improving mechanical properties and thermal conductivity for the brake rotor material that made from a gray cast iron type (A according to ASTM A247). The study accompanied with a full description of the microstructure evolution in each step of heat treatments that followed. It is found that, the quenching followed by a tempering process at 500°C can give a better UTS, and elongation at the same numbers of hardness. Thermal conductivity which is the prime requirements in brake rotor applications also improved according to the microstructure evolution.

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Article
Damaging of Steel-Oil Pipes by Erosion and Erosion -Corrosion Phenomena

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Abstract

Erosion and erosion-corrosion have important role in oil fields especially in steel oil pipelines. Therefore; in the present work erosion and erosion-corrosion tests are studied individually to investigate the relation between erosion and erosion-corrosion processes and to quantify the synergy (that is caused by erosion) in realistic flow environments. The experimental work tests were done using special device which was designed and manufactured according to (G 73) ASTM. The experimental work tests were achieved using traditional weight loss technique to measure weight loss rates in (gmd) unit. Also the microstructure observations of the test specimens were studied. It was observed that whole tests were conducted on oil pipe (X 60) made of low carbon steel in plate form, tests were made on corrosion using 3.5 wt % sodium chloride. (NaCl) solution as sea water purged with CO2 gas as the corrosive medium in crude oil , but in erosion-corrosion 1 wt % silica sand was added as slurry to that medium, pure erosion using 1 wt % silica sand as the erodent in distilled water purged with N2 gas as anti corrosive medium to get erosion just during pure erosion , all tests above were done in pumped media and pumped media had constant pressure of 1 bar, flow rate Q = 36 L/min, temperature ≈ 25 ºC and pH = 4.4 for erosive-corrosive media but pH = 7.4 for erosive medium. After traditional weight loss technique was achieved, it was found that erosion rate (E.R) was smaller than that of erosion-corrosion rate(E-C.R)

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Article
A STUDY OF WEAR RATE BEHAVIOR OF POLYESTER REINFORCED BY SILICA (Sio2) PARTICLES .
دراسة سلوك معدل البلى للبولي أستر المقوى بدقائق السليكا (Sio2)

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Abstract

In this research the wear rate of one type of the thermosetting polymer (polyester) reinforced by ceramic particles (silica) has been investigated. A Pin -on- Disc wear testing machine of variable speed has been used. Flat against flat sliding surfaces under variable working parameters conditions have been tested. Statistical and mathematical analyses were used to the processing of the experimental data. A mathematical model was done which shows the wear rate of composite materials as a function of grain size and weight fraction. The results of flat sliding surfaces show that the wear rate of the specimens depends heavily on the working condition. It increases with the increase of the load and sliding speed. The results also show that the wear rate decreases with the increase of the weight fraction and the decrease of the grain size of the reinforcing particles. The optimum wear resistance of the reinforced polyester was at weight fraction of ( 20 % ) and grain size of ( 25 m).


Article
Unidirectional Solidification of (Al-Si) Eutectic Alloy

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Abstract

This paper provides an overview of the mechanical properties of reinforced Al-12%Si alloy by uni-directional of the eutectic phases in specific direction. A special solidification unit have been designed and manufactured to ensure the correct orientation of growing eutectic phase. Two types of insulation materials have been used to isolate the carbon steel mold of solidification unit, (dry sand and glass wool). The second type insulator found to be favorable in augmenting the growth and uni-direction of eutectic phase with the conditions of cold water flow through the unit. The produced microstructure consists of little elongated α-phase with a noticeable correct orientation of the growing discontinuous eutectic phase in the direction of heat sink. Hardness, tension, compression and impact properties have improved in comparison with the samples of free mold isolation case (i.e. free solidification). These results reflect directly the effect of uni-directional growth of eutectic phase in the reinforcement process of the investigated alloy as an in situ-composite material.

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Article
Effect of aging and step –quenched heat treatment on the Martensitic transformation of CuZnAl shape memory alloy
تأثيرمعاملات الازمان و الإخماد المرحلي على التحول المارتنسايتي لسبيكة تستعيد شكلها من نحاس زنك المنيوم

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Abstract

There are many parameters affecting on the martensitic transformation of nonferrous alloys such as point defects, pores and heat treatment. In this work, the effect of aging after direct quenching treatment and step-quenched treatment on the Martensitic transformation of porous CuZnAL alloy are studied. X-ray diffraction analysis is based to identify phases presence in the microstructure of examined specimens. Optical microscopy and scanning electron microscopy examinations have also studied for prepared samples. It has been shown that aging and step-queched heat treatment lead to precipitate some intermetallic compounds in the Martensite matrix which make the lower percentage of shape memory effects for prepared alloy.


Article
Effect of Alloying Elements and Heat Treatment on Behavior of the Alloy (Cu,Al) Used in Marine Industries
تأثير عناصر السبك والتعامل الحراري على سلوك سبائك ذات أساس (Cu-Al)المستخدمة في الصناعات البحرية

Authors: *Faisel A.M.Al-Bassam
Pages: 143-165
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Abstract

The research deals with using powder metallurgy in atmospheric vacuum to prepare samples with (Cu-9.5Al). The silicon and nickel elements are added with (3wt%) and (5wt%) to (Cu-9.5Al)based respectively. Also (3wt%Si,5wt%Ni,1wt%Mn,4wt%Fe) elements are added to alloy based.Several tests were carried out ,such as Green, final porosity ,densities, compression, wear with (Pin-on-Disk)- type ,hardness. Corrosion tests, which include the simple immersion method and corrosion /erosion. The study indicated the increase in weight loss for corrosion/erosion test with phase transformation before and after heat treatment. The results indicate that the added alloy elements to the alloy based increase in corrosion resistance about (113.3 – 566.6%). Also high resistance in corrosion/erosion of two alloys are calculated. When the heat treatment are carried out, the improvement ratio is (488.9%),and the hardness has (185HV) value. The compression strength and ductility have improved with excellent value. The mechanical wear resistance have low change after heat treatment. While, the addition of (Si) and all the above mentioned metals to the base alloy, increase the resistance to wear and give the lowest corrosion The change case in weight with time indicate a stable case after exposed to corrosion media. The addition of (Si) metal with (3wt%) gave higher value in resistance to sliding wear and follow in (Fe) metal in the same behavior, where the improvement ratio, are (165%) and (126%). Alloy (Cu-Al-Ni-Mn-Fe-Si) also demonstrates a high hardness, low corrosion rate in sea water, good resistance to wear and compressive strain. These improvements were attributed to enhancement of properties of alloy based (Cu – 9.5 Al) used in Marine propellers industry.

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