Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

Loading...
Contact info

Jadriyah, Baghdad
Iraq
Mobile:
Email: joengbag@uobaghdad.edu.iq

Table of content: 2007 volume:13 issue:2

Article
Patterns' analysis
تحليـــــل الأنســـاق

Loading...
Loading...
Abstract

It is possible to infer some facts by capturing them directly or trying to trace their evolutions and changes mentally. This will guarantee human beings a sort of self-confidence, control and power. Some sustained patterns of natural, biological and human artifacts provide trusty physical and objective proofs on their success and survive. The research claims that the secret beyond the success of these patterns lies in ambiguous or hidden or invisible orders within the seeming randomness and complexity. Successful systems reflect distinguishable order when they reach a critical threshold of stability and self-organizing between their trends to connect and to compact. Then, patterns can reveal themselves and express their similar structural and morphological changes. In the same manner, guiding other systems to reach such edges and thresholds may ensure having successful patterns, solving serious problems and leading the way ahead correctly. The research depends on a new mathematical tool from the Fractal Geometry to reveal and measure the hidden orders in these patterns by calculating the repetitions of form's changes. This tool could be defined as a Fractal Dimension (D), which is considered to be a sensitive index or parameter of the system's behaviors. Also, the research adopts the comparative analysis method of analyze and measure the form of a trusty successful, natural and sustained pattern of a fruit trees orchard, trying to find a numerical order by calculating its fractal dimension. The obtained fractal dimension represents a referential base in analyzing some patterns of urban systems (e.g. Baghdad's two dimensional image), a reliable index and parameter to detect the system's behaviors and trends to connect or to compact. Comparing the pattern of an existing urban fabric for the city of Baghdad with the orchard's pattern refers to an obvious defect in the inner structure and morphology of the capital. Baghdad tends to connect rather than to compact in a pathological way. The research ends with the need for urgent and careful interference to tune the parameters of connectivity and compactivity equally by suitable and practical suggestions and recommendations.


Article
Prediction of Mass Transfer Coefficient in Bubble Column Using Artificial Neural Network

Authors: Salih A. Salih --- Adil A. Al-Hemiri
Pages: 1327-1342
Loading...
Loading...
Abstract

The volumetric mass transfer coefficient kL.a was calculated using two gases (air and CO2) in water and NaOH solution. The experiments were carried out using 0.1 m column diameter. Empirical and Artificial Neural Network (ANN) correlation were developed to predicted mass transfer coefficient in form of dimensionless groups (Sh, Re,Bo and We). The use of Back Propagation Neural Network (BPNN) gave better results than other correlations found in literature and than the empirical one found in this study.


Article
Copper Recovery from Spent Etchant Cupric Chloride Solution by Electrowinning Method

Authors: Zuhaira N. Hanna --- Aprael S. Yaro
Pages: 1344-1353
Loading...
Loading...
Abstract

Recovery of copper from actual spent etchant cupric chloride solution used in manufacturing of printed circuit board (PCB) containing 124 g/l Cu^+2 ions concentration and 60 g/l hydrochloric acid was investigated in a batch mode jacketed tank. This tank was constructed with inner dimensions of 19×10×15 cm^3. Cylindrical rode-shape titanium was used as cathode, while two rectangular shaped graphite were used as anodes. The parameters studied were: current density (0.16-0.30 A/cm^2), copper concentration in etchant solution (30-124 g/l) and the temperature (25-45 °C). The highest current efficiency obtained was about 92% and the lowest power consumption achieved was about 2.7 W.h/g within the temperature range 25-35 °C.


Article
Design and Implementation of Computer Aided System for Quality Improvement Inspection and Testing For Boiler In Thermal Electric Power Station

Authors: Hala T.Abid --- Ahmed Abdul-Aza andl --- Mohammed Y.Fattah
Pages: 1354-1368
Loading...
Loading...
Abstract

There is a problem, in Iraq, due to the multitude of malfunction after the overall annual maintenance has been achieved, and that raises the cost of continuous repairs, one of the reasons of this problem, is the absence of planned testing and automation for testing devices, the second reason is the neglect of concentrating on a database, the third one is not following an integrated testing system for all parts, as well as, there are no documented reports for inspected parts. Most of various nondestructive inspection techniques have been achieved random selection steps. The lack of a documentation system leads to lack of historical information a bout failures parts of a boiler that affect inspection decision process. This paper summarizes Programmed system designing and computerized for internal inspection of boiler heatsurfaces (IIBHS) at Nassyriah power station as an example.


Article
Systolic Array for Realization of Discrete Wavelet Transform

Authors: Ahmed S. Hadi --- Waleed A. Mahmoud
Pages: 1370-1378
Loading...
Loading...
Abstract

This paper introduce a new method for using a systolic array to perform the one, and two dimension discrete wavelet transform (1-D DWT, and 2-D DWT). The 1-D needs only a semi-systolic array for its realization. However, it was found that the 2-D method needs the combination of two types of semi-systolic array into one systolic array to achieve its implementation.


Article
Confinement and Expansion Models for Nonlinear Analysis of Reinforced Concrete Members

Authors: Abbas A. Allawi --- Ihsan Al-Shaarbaf --- Khalid S. Mahmoud
Pages: 1380-1397
Loading...
Loading...
Abstract

This research pertains to expand the formulation and applicability of using confinement and expansion due to Poisson’s ratio models for three dimensional non-linear finite element analysis of reinforced concrete members. A plasticity based model that acknowledges the asymmetric response of reinforced concrete under multiaxial stress conditions is used to account for the strength improvement under conditions of triaxial compression. Complex behavior of concrete such as compression softening and tension softening are incorporated to simulate concrete behavior. DIANA software is used for finite element analysis with the inclusion of confinement and expansion effects. The concept of material pre-strains is extended to accommodate modeling of the Poison’s ratio effect. The applicability of the suggested confinement and expansion models are verified by comparing the results of Kupfer and Vecchio – Collins tests on shear panels with that obtained from DIANA software. These comparisons illustrate the ability of the confinement and expansion models to obtain the response of reinforced concrete members subjected to multiaxial stress conditions.


Article
Analytical and Numerical Stress Analysis of Thick Cylinder Subjected To Internal Pressure

Authors: Oday. I. Abdullah --- Adnan N. Jamel
Pages: 1399-1416
Loading...
Loading...
Abstract

The present work is an attempt to investigate the vibrations characteristics and effect of static stresses and deformation in partially pressurized thick cylindrical shells, such as the gun barrels. The method used cover analytical investigation developed to determine static stresses and deformation along the thick cylindrical shell using LAME'S equation. The numerical investigation is developed using the finite element method with axisymmetric element (Plane 42) four nodes to determine the static response and solid element (Solid 45) eight nodes for vibration analysis by using the ANSYS package. The obtained results show a good agreement with the other investigators. It's found that the natural frequency of the selected models almost equal (150. Hz) and these results indicate that the frequency of powder gasses pressure more than (150 Hz) to be far away from resonance phenomena.


Article
Natural Convection Heat Transfer in a Vertical Concentric Annulus

Authors: Akeel A. Mohammed
Pages: 1417-1427
Loading...
Loading...
Abstract

Experiments were carried out to study the local and average heat transfer by natural convection in a vertical concentric cylindrical annulus. The experimental setup consists of an annulus has a radius ratio of 0.555 and inner cylinder with a heated length 1.2m subjected to the constant heat flux while the outer cylinder is subjected to the ambient temperature. The investigation covers heat flux range from 58.2 W/m^2 to 274.31 W/m^2. Results show an increase in the natural convection as heat flux increases leads to an improve in the heat transfer process. An empirical equation of average Nusselt number as a function of Raylieh number was deduced .


Article
Numerical Simulation of Two Dimensional Transient Natural Convection Heat Transfer from Isothermal Horizontal Cylindrical Annuli

Authors: Jasim M. A. Al-lateef --- Ayad K. Hassan
Pages: 1429-1444
Loading...
Loading...
Abstract

Numerical solutions are presented for the transient natural convection heat transfer problem in horizontal isothermal cylindrical annuli, enclosed in heated inner and cooled outer cylinders. Solutions for laminar case were obtained within Grashof number based on the inner diameter which varied from 1x10^2 to 1x10^5 in air. Both vorticity and energy equations were solved using alternating direction implicit (ADI) method and stream function equation by successive over relaxation (SOR) method. The structure of fluid flow such as a velocity vector and temperature distribution as well as Nusselt number were obtained and the effect of diameter ratio on them is examined. In addition, the Grashof number was changed with the influence of variation Prandtle number and diameter ratio. Our numerical calculation are summarized by Nussult number vs. Grashof number curves with diameter ratios and prandtl as a parameter, which serves as a guide to natural convection heat transfer calculated from annulus. Good agreement with previous data were obtained.


Article
Evaluation of Temperature Distribution And Fluid Flow In Fusion Welding Processes

Loading...
Loading...
Abstract

A theoretical study of heat transfer and fluid flow phenomena in welding process has been carried out in the present work. The study involved the numerical solution of the transient Navier-Stokes and Energy equations of the weld pool region by using Finite Difference Method. The electromagnetic force field and buoyancy were included in the formulation The stream-vorticity formulation was used in the mathematical model. The numerical solution is capable of calculating the vorticity, stream function, velocity, temperature, and the interface movement of the weld pool in Gas Metal Arc Welding (GMAW). The model can be used to solve the Gas Tungesten Arc Welding (GTAW) problem. A numerical calculations algorithm was developed to carry out the numerical solution. The numerical results showed that the finger penetration phenomena occurs in the Gas Metal Arc weld is adequately explained through the application of the model. It is found that the frequency of spray transfer is a dominant factor in addition to shape of the weld pool geometry. A verification of numerical results was made through a comparison with a previous work, the agreement was good, confirming the capability and reliability of the proposed numerical algorithm in calculating fluid flow and heat transfer in Gas Metal Arc weld pools.


Article
Analysis of Corner Beam-Column Junction with Inclusion of the Effect of Construction Joints

Authors: Dina M. Hamza --- Husain M. Husain
Pages: 1464-1483
Loading...
Loading...
Abstract

This paper describes a comparison between beam-column junctions with and without construction joint, also, a parametric study deals with construction joint is presented by taking various conditions of the junction. These include the various positions of the construction joint, the axial load on the column, strength of concrete in the second cast and the amount of dowels crossing the joint. By developing a computer program which was originally written by Dr. Ihsan Al-Shaarbaf (1990), (P3DNFEA, program of three dimensional nonlinear finite element analysis), to consider the effect of construction joint depending on the fact that the shear force can be transmitted across the shear plane either by interlocking of the aggregate particles protruding from each face or by dowel action of the reinforcement crossing the cracks by using Fronteddu’s and Millard’s models, respectively. It is concluded that the construction joints existed in the beam-column junctions result in a significant reduction in the in-plane shear stiffness and it would affect only on the rotation and shear strains of the joint.


Article
Blunder Detection Techniques in Adjustment Computations

Authors: Jareer Jabir --- Hussein Alwan --- Bashar Saleem
Pages: 1485-1497
Loading...
Loading...
Abstract

In adjustment of geodetic and photogrammetric networks, the surveying engineer faces many problems, such as errors of blunder nature in the observations (when comparing the homogeny of precision) make these observations odd from the result, and effecting directly on observation values after adjustment, and the statistical results after analysis as, adjusted coordinates of points, standard deviations, and ellipse of errors. The research is deal with some of the most common usage of statistical methods to detect these odds observations to confirm which best method is, by studying the advantages and disadvantages of each method to geodetic network. Three statistical methods will use in the analysis, these are:- 1. Standardized residuals method 2. F-t test 3. Robust estimation method The adjustments were accomplished by preparing a Matlab program with the three blunder detection methods and the results were evaluated and some scientific conclusions were reached. It was found that the robust estimation method represent the better blunder detection technique due to its ability in what is called (multi-blunder detection) , and the resulted higher accuracy indices.


Article
Numerical and Experimental Investigation of Flow Field Inside Arteries and Veins

Loading...
Loading...
Abstract

Numerical and experimental investigation of blood flow through stenotic and tapered arteries under pulsation condition are studied. Blood is considered as non-Newtonian fluid. Artery is considered as a rigid wall tapered vessel with different tapering angles (0.5°, 1°,1.5°), as well as, straight vessel for comparison. The governing equations have been written in stream- vorticity method and are transformed into generalized coordinate system. The time marching has been employed to solve the resulting partial differential equations. The experimental work carried out to examine pressure in vessel and pressure drop across the stenosis under pulsation condition. Differential pressure transducer coupled to the data acquision card type PCI-911DG, which is built in computer was used to record pressure data. The results showed that, as a tapering angle increases (0.5°, 1°, 1.5°) both wall shear stress and pressure drop increasing, also as stenosis increases (50%, 60%, 75%) both wall shear stress and pressure drop increasing. These behaviors are found in literature, pressure drop is used to compare experimental data and numerical results, which indicates agreement. As the distance into taper section increased both wall shear stress and pressure drop are increased, as well as, both wall shear stresses and pressure drop increased with inlet flow rate increased, while decreased with inlet diameter increase.

Keywords


Article
Numerical Study for a Three Dimensional Laminar Natural Convection Heat Transfer from an Isothermal Heated Horizontal and Inclined Square Plate and With a Circular Hole

Authors: Ikhlase M.Fayed --- Yasmeen Hameed Abd
Pages: 1519-1538
Loading...
Loading...
Abstract

A theoretical study for a three-dimensional natural convection heat transfer from an isothermal horizontal , vertical and inclined heated square flat plates (with and without circular hole) has been done in the present work. The study involved the numerical solution of the transient Navier-Stokes and energy equations by using finite deference method (F.D.M.). The complete Navier-Stokes equation are transformed and expressed in terms of vorticity-vector potential. The Energy and Vorticity equations were solved by using an Alternating Direction Implicit (ADI) method because they are transient equations of parabolic portion, and the Vector potential is solved by using an equations Successive Over-Relaxation (S.O.R) method because it is from elliptic portion. The numerical solution is capable of calculating the Vector potential, three components of Vorticity and temperature field of the calculation domain. The numerical results were obtained in rang of Grashof number (10^3≤Gr≤5x10^4) with Prandtl number of (0.72) for square flat plate and the other consist a circle hole with ratio 0.6 and 0.8 diameter of the hole to main square side length. The numerical results showed that the main process of heat transfer is conduction for Grashof number less than 10^3 and convection for Grashof number larger than 10^3 and the results of local Nusselt number show fairly large dependence on inclination angle. For horizontal plate facing upward and downward, average Nusselt number is proportional to one-fifth power of Rayleigh number, and there is a significant difference in heat transfer rates between the upward and downward cases. For horizontal plate with circle hole facing upward for Grashof number 10^4, the effect of core portion caused a limited increment in the heat transfer rate, where as for the facing downward case, the effect was larger and the maximum value of heat transfer rates is be for square flat plate with circle hole by ratio 0.6 for all inclination angles. With the increase of Grashof number to 5x104 heat transfer rates decrease except the square horizontal flat plate with circle hole by ratio 0.6 . The average Nusselt number increases with the increase of inclination of plates facing upward to reach to the higher average Nusselt number at vertical position then decrease with increase of inclination of plates. And the maximum value of average Nusselt number is depended on the ratio of diameter of the hole to main square side length, showed that the maximum temperature gradient occurs at the external edge of the horizontal plate (with and without circle hole) facing upward and at the lower external edge in inclined case. The numerical results was made through comparison with a previous numerical and experimental work, the agreement was good.

Table of content: volume: issue: