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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: 2015 volume:15 issue:3

Article
GAS-LIQUID SLUG FREQUENCY AND SLUG UNIT LENGTH IN HORIZONTAL PIPES
الغاز-السائل تردد الموجة ووحدة طول الموجة بالانابيب الافقية

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Abstract

The object of this work is to gain insight into gas-liquid slug flow frequency and the slug unit lengths in horizontal circular transparent pipe of 25.4mm inner diameter and 6m length, experiments done at atmospheric condition with air and water as the working fluids. The superficial gas velocity ranged from 3.947 m/s to 6.579 ms with superficial liquid velocity around 0.986 m/s and 1.974 ms. The effects of superficial gas velocity, superficial liquid velocity on slug frequency and slug unit lengths were taken into account. However, the essentials of the problem involve the determination of the slug frequency and slug unit length.In this experimental work a video camera system with image processing technique by MATLAB were used to extract the slug frequency and the slug unit lengths, which contain slug body length and Taylor bubble length or film region length. New data for slug frequency and slug unit lengths were found which achieved good agreements with the previous works.


Article
EFFECT OF PITCH ANGLE ON STATIC CHARACTERISTICS OF A HELICAL MACHINED SPRING
تأثير زاوية الخطوة على الخصائص الستاتيكية للنوابض الحلزونية المشغلة

Authors: Sami Ali Nama سامي علي نعمه
Pages: 181-190
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Abstract

This paper investigates the linear static and modal analysis of helical machined springs theoretically and numerically using the finite element method with the aid of SolidWorks software. A rectangular cross sectional area of a helical spring was studied with different pitch angle, it was found that increasing the pitch angle increases the spring deflection and decreases both the maximum shear stress and the fundamental natural frequency. Two cases were studied for machined spring, one with different pitch angle and the other with different number of spring starts. The machined helical spring showed better results for maximum shear stress and deflection compared with the conventional helical one. With multiple starts machined helical spring, the spring performance can be improved for a great extent. The results showed that SolidWorks software can be used effectively in modeling and analyzing machined spring.


Article
A UNIFIED METHOD FOR B-SPLINE’S SURFACE MODELING (INNOVATIVE METHOD FOR DATA TRANSFORMATION FROM CAD TO CAM PROGRAMS)
طريقة موحدة لنمذجة السطوح( طريقة مبتكرة لنقل المعلومات من برنامج التصميم ))CAD)الى برنامج التصنيع (CAM)

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Abstract

In present work, a unified method for geometric transfer from CAD to CAM program has been investigated using iterative process. The B-spline objects (curves and surfaces) of 3rd degree one patch matrix had been derived and formulated using MATLAB program to construct a computer program for the geometric transfer as a case study. The procedure of converting the sculpture surfaces from CAD program to CAM program without any geometrical distortion had been presented. The implementation of transfer data and the simulation using UGS program during transformation of any complex profile shape from CAD to CAM program is done without any distortion in final profile in CAM program. It was found that the results obtained by applying the present method which utilizes a less time as compared with the other methods are in a good agreement with the experimental results.


Article
TAGUCHI BASED GREY RELATIONAL ANALYSIS FOR MULTI-OBJECTIVE OPTIMIZATION OF CUTTING PARAMETERS IN HARD TURNING
تحليل الامثلية متعددة الاهداف لعوامل عملية القطع للخراطة الصلدة باستخدام طريقة تاكوجي مع طريقة التحليل الرمادي

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Abstract

In this paper, the combination between Taguchi method and grey relational analysis was applied as a key solution for multi objective optimization problem in turning of hard metal. The variable were; cutting speed, feed rate, depth of cut, and tool nose radius. These parameters were optimized with respect to surface roughness and metal removal rate. The surface roughness was to be minimized; on the other hand the metal removal rate is to be maximized. This problem was solved by converting the multi objective optimization to single objective optimization by applying the grey relational grade analysis. L16 Taguchi orthogonal array is used in this paper. The confirmation results show that the grey relational grade analysis is an effective tool to improve the multi quality objective process.


Article
OPTIMIZATION AND PREDICTION OF THE OPTIMAL CUTTING CONDITIONS AFFECTING THE SURFACE ROUGHNESS OF HIGH CARBON ALLOY STEEL
الامثلية والتنبؤ بظروف القطع المثلى المؤثرة على الخشونة السطحية لفولاذ سبائكي عالي الكاربون

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Abstract

In this research, optimization of turning cutting conditions and prediction of surface roughness has been satisfactorily accomplished. Taguchi method was applied and second – order mathematical model used for prediction has been developed. Standard L9 Taguchi orthogonal array, S/N ratio through using the quality characteristic ‘the-lower-the-better’, and ANOVA technique were all adopted to determine the optimum cutting parameters and the more significant factor among them. The parameters that have considered are Spindle speed S, feed rate f, and depth of cut a. Nine specimens were machined according to the levels of parameters, and surface roughness (Ra) values were measured three times for each experiment. The optimum conditions obtained were 1200 rpm spindle speed, 0.12 mm/rev feed rate, and 0.7 mm depth of cut. Among them, the more significant factor is feed rate followed by spindle speed and depth of cut respectively. Based on the results of prediction by the second – order model, it can be concluded that it is a very appropriate to predict the surface roughness of high carbon steel. Confirmation results showed that the predicted values and measured values were dramatically close. This indicates that the Taguchi method and multiple regression can be effectively used to optimize and predict the surface roughness such that the coefficient of determination was found to be 99.82 % with average error not exceed 1.12 %.


Article
OIL-WATER ANNULAR TWO-PHASE FLOW IN HORIZONTAL PIPE
الجريان ثنائي الطور (زيت-ماء) خلال الانابيب الحلقية الافقية

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Abstract

The objective of this work is to gain insight into liquid-liquid annular flow, two-component Iraqi gasoil-water flow lengths in horizontal circular transparent pipe of 32mm inner diameter and 6m length, experiments done at atmospheric condition with oil and water as the working fluids. The flow patterns that appear are classified in flow pattern maps as functions of either mixture velocity and water cut or superficial velocities. The superficial water velocity ranged from 1.69 m/s to 3.38 ms with superficial oil velocity around 0.39 m/s to 1.58 ms. The effects of superficial water velocity, superficial oil velocity on annular flow lengths were taken into account. However, the essentials of the problem involve the determination of the pressure gradient. In this experimental work a video camera "high speed camera" system with image processing technique by MATLAB were used to extract the hold up for the fluid that being the annular flow. The theoretical study was executed using fluent program, a modified turbulent diffusion model is adopted. Simulation results show more physical predictions with respect to the particle deposition process and concentration profile. New data for hold up lengths were found which achieved good agreements with the previous works.

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