Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 22, Issue 1

Volume 22, Issue 1, Winter and Spring 2014, Page 1-122


Finite Element Analysis of Draw Beads in Deep Drawing Processes

Dr. Muhsen Jaber; Dr. Azal Refa; Alaa Dahham

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 1-13
DOI: 10.33899/rengj.2014.87017

The design optimization of deep drawing process in manufacturing is proposed
to control the final shape of the work piece after elastic spring back. The manufacturing
process design problem is formulated to minimize the difference between the shape of the
desired work piece geometry and the final analysis. This paper aims to predict the
wrinkling and thinning (necking) failure and to study the effect of using draw bead on
the thickness distribution along the cup. In this paper to analysis the deep drawing
process with draw beads the FEM code (ANSYS) version 12.1 packages is used, which is
able to simulate various metal forming processes such as deep drawing. The best results
and the low variation between the maximum thickness and minimum thickness is found
at the half circle shapes of Draw Bead and itَ s about 10.4% thinning and 26.5%
thickening

Stochastic Dynamic Programming Model for Single Reservoir

A. R.M. Tawfiiq; Dr. K. A. Al-MohseenA

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 1-14
DOI: 10.33899/rengj.2014.87035

The present research aims to study the feasibility of using a Stochastic Dynamic
Programming model "SDP" to calculate the optimal operating policy for a single
reservoir system.
The study required to write two computer codes; one is for Deterministic Dynamic
Programming "DDP" and the other is for Stochastic Dynamic Programming "SDP"
using MATLAB platform.
A comparison study has been conducted between the optimal operating policies
obtained from the two models. The results revealed that the SDP outputs were more
realistic than those obtained by DDP, as the first gives the reservoir operator more
flexibility to deal with the variation of the inflow to the reservoir, while the second is
not.
Additionally, a simple nomographhas been introduced to assist the operator of the
reservoir to manage a wide variety of inflow scenarios.

Buckling analysis of Composite Plate with Central Elliptical Cut out

Dr. Rafi K. Albazzaz; el Saleh Al-Jameel

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 14-25
DOI: 10.33899/rengj.2014.87012

In this study, the multilayer composite plates consist from aluminum, brass,
and steel with unsaturated polyester Resin (UPE) as a core material. The plates having a
central circular, elliptical holes. The buckling parameters such as aspect ratios and
different hole orientation angles have been analyzed numerically.These parameters have
been applied at different layers of materials both metallic and non metallic. Analyses
were carried out using finite element method (FEM) through the application of special
numerical program written in APDL by ANSYS software. Result shows that the
buckling load were highly dependent on the type of composite material, and the
buckling load increased by increasing elliptical hole orientation angle. Increasing of
major and minor diameters of elliptical holes with plate b/w ratios were decrease the
buckling load for the multilayer composite plate

Analysis of Rainfall intensity at Hammam Al – Alil in Mosul city

Dr. Basil Khether Dawood; Younis Najib Saeed

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 15-26
DOI: 10.33899/rengj.2014.87032

In this research the rainfall intensity data in mm/hr for the period ( 1982-1990 )
of nine years are collected for duration 3 to 13 hour from a station at Hamam - Al Alil
( Small town 25 km from Mosul ). Data generation for long period is generated from the
historical records by using uniform and normal distribution.
Physical and Statistical tests for comparing the historical and generated data will
indicate that Markov process of 1st degree is better than 2nd degree for two distribution.

Stress analysis on main landing gear for small aircraft

Dr. Rui Pires; Prof .Dr. S. M.J.Ali; A.S. A. Al-banaa

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 26-33
DOI: 10.33899/rengj.2014.87009

Main landing gear is important part in aircraft, its help the aircraft to takeoff
,landing, and taxing in the ground .This part subject to high stress at landing due to
impact, there are two important force act on landing gear during touch, Normal force
and a spin-up back force .Normal Force is a great force that act on landing gear and its
generate due to Normal impact and its cause to bend landing gear to up , this force can
be calculated form Newton second law, and the spin-up back force generated at touch
when the tire not rotate causing the landing gear leg to bend to backward the value of
this value can be assumed equals to 0.5 from the normal force. In this study this forces
type are considered to make stress analysis of the landing gear for Cessna 152 during
touchdown time, after that three model are considered to reduce value of stress on this
landing gear by keeping the dimension and material as on original model and making
positive curves on the landing gear leg, and shown that when making the positive curve
this will reduce the value of the stress and deflection on the landing gear depending on
the principle of bending moment in the beams.

Time series analysis of incoming water volumes to Mosul dam from Tigris river and use it for prediction

Younis Najib Saeed

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 27-39
DOI: 10.33899/rengj.2014.87029

Data of monthly volumes of discharges reaching Mosul Dam reservoir for a
period of (15) years, multiplied by (12) month and thus get a time series consisting of
(180) value for monthly volumes of discharges are organized and collected for years
( 1985 – 1999 ). A synthetic time series were obtained by applying multiplicative
decomposition of a time series method. Where normal method (which depends on the
values of the two components (trend and seasonal) only) was applied on the historical
data after conversion to the normal distribution , and the standard error (MAPE) of this
method was (39%). For the purpose of improving the results were an amendment in this
research on this method by using the modified method in this research which adopting
the values of components other than the series (cycles and random) and enter them in
the calculation the values of synthetic time series by multiplying their approximate
values in the results of the values of synthetic time series extracted by the normal
method above , in terms of improved the error measure value (MAPE) of the modified
method to (32%).
The results showed the effectiveness of the modified method used in this
research in the prediction of incoming water volumes for years ( 2000 – 2004 ), where
tests showed conformity (average, standard deviation, autocorrelation coefficient,
density analysis) and there is a match between the predicted values with historical
values.

The Effect of Unbalance on the Cyclic Stresses of a Flexible Rotor Mounted on Oil-Film Bearings Using Finite Elements Technique (ANSYS)

O. A. Mohammed; A. M. Abdullah; Kh. E. Hammo

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 34-43
DOI: 10.33899/rengj.2014.87004

Eccentricity problem is considered as one of the most important and common
repeated problems in rotary shafts in all machines. This will lead to generation of
vibration and extra loads on bearings. Also a non-uniformity can occur in distribution of
applied load on all the surface of the bearing which being concentrated on one or two
sides of the bearing surface. The purpose of this research is to investigate the effect of
the unbalance on the values of stresses and deflections for a flexible rotor supported by
oil film bearings. Various rotational speeds and unbalance effects has been taken in to
consideration. A dynamical model of the system has been built. The parameters of
journal bearing have been determined using MATLAB/ simulink software. ANSYS
program has been used for the analysis of the stresses produced during rotation.
Keywords: Unbalance, Eccentricity, Simulation, Rotor Shaft.

The Impact of Spatial Configuration Properties of The Courtyard on Special System Intelligibility of Islamic palaces

D. Hafsa Ramzi Alomri; Raeed S. Ahmed Alnumman

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 40-55
DOI: 10.33899/rengj.2014.87027

The architectural cultural heritage of any nation is one of the most important basic components
that reflect the authenticity and depth civilization of that nations. Architecture as a mirror that
reflects all aspects of life (social, economic, technical, environmental, political) of the nation in
any age of the ages. many studies focused on research in the local historical properties of the
nation to define the architectural privacy (planning, design) to those of the nation. Many of the
studies that analysis of Islamic buildings in Arab city are indicated that courtyard is one of the
most important elements in both religious, civil architecture and often is used in the hot regions
despite differing effects of social, cultural and religious aspects indicator a success architect
solution for the different functional needs. The idea of courtyard is dominated the design ideas
in a different buildings where it was restrict the design process as it a restriction to the
different functional needs and reflected to the traditional architectural composition. Islamic
palaces buildings are represented various aspects of life, there are a reflection of social and
economic life and political across of different time periods that have passed the nation , and the
nature of the climatic conditions .
From the previous studies that focused on the courtyard in architectural environment specially
in Islamic palaces buildings appears that of the Intelligibility of the Special System of these
buildings is insufficiency and unclearness in this studies. this paper has taken this as a
research case , and will aims to be determined by Analysis a select group of various and different
functional type of Islamic palaces

Natural Convection Heat Transfer from Two Perpendicular Heated Surfaces Embedded In Porous Cavity

Noor Moneer Basher; Dr. Amir Sultan Dawood

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 44-56
DOI: 10.33899/rengj.2014.86999

The effect of modified Rayleigh number, positions and lengths of two
perpendicular heated surfaces on natural convection heat transfer was studied
numerically, where the two surfaces are embedded in square cavity filled with saturated
porous medium. All walls of the cavity are kept at constant temperature. Indirect
numerical method was used to solve the governing equations, which are: the nondimensional
Darcy flow equation as well as the non-dimensional energy equation, which
were solved numerically by finite difference method using Gauss-Seidel iteration
coupled with (Successive Under Relaxation) technique. This study covered a wide range
of modified Rayleigh number range (100-1000), nine positions and the ratios of length of
vertical surface to the horizontal (0.5,1, 2). It was found that the positions of two heated
surfaces have small effect on the heat transfer rate, but any increase in the length of two
surfaces leads to an increase in average Nusselt number, but an increase in the length of
vertical surface leads to more increase in the average Nusselt number

Freehand Drawings versus CAD Drawings in the Conceptual Architectural Design Phase

Dr. Dhuha Abdulgani Abdulaziz Al-kazzaz

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 56-79
DOI: 10.33899/rengj.2014.87025

In the last decade, the value of freehand drawing as a design tool in both education and
practice is open to debate as a result of the accessibility of digitised drawing tools such as
CAD systems and the relative ease with which a design can be presented and realised
using computerised techniques such as parametric modelling and rapid prototyping.
The conceptual design stage is the most critical in the design process. Despite the fact
that most of the widespread computer aided design systems (such as AutoCAD and
3DSMax) are primarily directed towards the more detailed stage of design process. Even
so, there are architects today who have abandoned the use of a pencil and paper, turning
to the computer during the creation of their design concepts.
The paper investigates the limitations of Computer Aided Drawing (CAD) systems
which make them unable to satisfy what freehand drawings are doing for the initial
design phase. To achieve this aim, the first section of this paper puts forward a
framework for the main roles of freehand drawings through the conceptual design
process. The second section investigates the capabilities of computer aided drawing tools
to achieve these roles by depending on the theory and practice of the use of CAD tools at
the initial design stage. The third section concludes the weakness and strength of
computer aided drawing systems in the conceptual design phase. The paper ends with
recommendations.

Radiation Effect on MHD Mixed Convection Flow Along an Isothermal Vertical Wedge Embedded in a Porous Medium with Heat Generation

Dr. Saddam Atteyia Mohammad

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 57-68
DOI: 10.33899/rengj.2014.86998

This paper study the effect of radiation on a steady mixed convection flow of a
viscous incompressible electrically conducting and radiating fluid over an isothermal
vertical wedge embedded in a porous medium. The governing nonlinear partial
differential equations and their boundary conditions are transformed into a nonsimilar
form by using a suitable dimensionless variables. The system of nonsimilar equations is
solved numerically using a finite difference method. The present results of local Nusselt
number are compared with previously published work for the case of Darcy solution.
The comparison is found to be in excellent agreement. The present results showed that
as the wedge angle parameter increases the local Nusselt number increases. Increasing
in the value of the square of the Hartmann number leads to decreasing the value of the
local Nusselt number. Increasing in the value of the radiation parameter leads to an
increase in the value of the local Nusselt number. Increasing in the value of the heat
generation parameter leads to decreasing the value of the local Nusselt number.
Increasing in the value of the radiation parameter in the presence of the square of the
Hartmann number and the heat generation parameter has a similar effect on the local
Nusselt number presented above but with less values.

Evaluation of Atmospheric and Aqueous Corrosion of Passenger Car Body in Mosul City through the Year 2009-2010

H. A. Al-kareem; G. M. Hannoush; R. J. Al - Ghadanfary

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 69-78
DOI: 10.33899/rengj.2014.86996

Corrosion of five steel bodies of passenger cars of models 1985, 1990, 1995, 2000, &
2005 that are used in Mosul city were studied under atmospheric and aqueous during
2009-2010. Atmospheric corrosion rates were below 1.7 mpy, which is classified as low
corrosion, this is due to dry weather conditions during the study period , and the quality
of steels of the car bodies. Aqueous corrosion rates were also low, below 4.57mpy, and
this is due to good water quality of Mosul , low Langelier saturation index, ideal
corrosion index, and the quality of steel body cars.
Key Words: Mosul city, Atmospheric Corrosion, Car Body Steels, 2010.

WiMAX Mesh Topology with Modified Fair Centralized Scheduling and Routing Algorithms Based on Testing Feature of Down-Node Group

Dr. A. I. A. Jabbar; Z. K. Farej

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 79-98
DOI: 10.33899/rengj.2014.86994

Multiple access interferences are the major limiting factors for the performance of
multihop WiMAX based Mesh Network (WMN). The routing algorithms play an
important role in reducing such interferences among the nodes of the WMN. In this paper
a new Routing Tree Construction Algorithm (RTCA) which is based on Balancing the data
and Parallelizing the routes of the data from nodes to BS is proposed and called Balanced-
Paralleled RTCA (Bala-Para-RTCA). This algorithm has a new Down-Node Group
Testing (DNGT) feature. This feature increases the conversion of primary into secondary
interferences which (in conjunction with directivity) can be avoided significantly by the
Modified Fair Relay Centralized Scheduling (MFRCS) algorithm, as a result concurrent
transmissions over a certain slot will be increased. So system performance is enhanced in
terms of scheduling length, links concurrency ratio (LCR) and average transmission delay
(ATD). Without directivity and relative to the standard Breadth First Tree (BFT) RTCA,
the simulation results of the proposed RTCA show concurrency ratio enhancement of
15.38% and 19.4% without and with DNGT respectively

Analysis and Design of Passive Filters to Reduce Line Current Harmonics for Controlled Rectifiers

Hussein I.Zynal; Bashar A.Fadeel

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 80-96
DOI: 10.33899/rengj.2014.87022

Many researchers have sought to use different methods to reduce harmonics
in the input current wave of the rectifier, In this study the method of passive filter
connections are used, which is the most commonly used method. The filters that have
been used in this study are connected in parallel (shunt) with the rectifier. Where the
idea of these filters to provide a path with a very low impedance to the harmonics of the
current. These filters must be capable of withstanding rated voltage of the system. In
this study two types of passive filters are explained and used (Single tuned filter and
Second order high-pass filters). Also mathematical analysis of these types of filters and
waves are given. Filters were designed at several values of the firing angles of the
rectifier.

Effect of the hydraulic detention time and the volumetric ratio of anaerobic to aerobic zone on the efficiency of the upgraded activated sludge units using (Bardenpho) system

Abeer.T. A. H. AL-Abdaly; Dr. K. K. Al-Ahmady

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 97-109
DOI: 10.33899/rengj.2014.87020

In this research, five experimental plants have been established and operated using
synthetic domestic wastewater in order to study the effect of some operational
parameters on the removal efficiency of organic and nutrients pollutants in Bardenpho
Process. The results of the research proved that the removal efficiency of organic,
nitrogen, and phosphorus materials were higher in the reactors that work by Bardenpho
process comparing to the ordinary activated sludge system. Also the biological sludge
resulted from Bardenpho reactors has better settling characteristics. Likewise, the pH
values in the plants work by Bardenpho process were lower than those in the plant that
work by ordinary activated sludge system. The results of the study also shown that the
removal efficiency of organic materials in the Bardenpho reactors increases by the
reduction of volumetric ratio of the anaerobic to aerobic zone, in contrast, the
concentrations of Nitrate, Ammonia, and Phosphate decrease by the reduction this ratio,
in addition, the value of SVI decreases by increasing the size of anaerobic zone. On the
other hand, The results also proved that increasing the hydraulic detention time (HRT)
lead to increase the efficiency of removing organic, nitrogen, and phosphorus materials
of the biological reactors that work by Bardenpho process. Moreover, increasing the
HRT leads to increase value of the sludge volume index (SVI) at all of the Bardenpho
and ordinary activated sludge reactors. In contrast, the value of pH drops by the
increasing of hydraulic detention time.

Preparation and Study of SnO2 MOM Structure by The Thermal Vacuum Evaporation Deposition

Omar Ghanim Ghazal; Dr. Luqman Sufer Ali

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 99-111
DOI: 10.33899/rengj.2014.86990

Resistive switching random access memory is one of the novel nonvolatile memory
technologies that, has a promising future for replacing the conventional FLASH memory. In
this work a detailed study made about the types of operations and understanding the
mechanisms of the resistance changing in the device. SnO2 thin films are deposited by using
Thermal Vacuum Evaporation deposition method at room temperature on Al/glass substrate
to produce Al/SnO2/Al/glass device structure. Optical properties are taken to measure the
optical band gap of SnO2. Resistive switching is observed by taking current voltage readings
at room temperature. RRAM cell showed unipolar resistive switching behavior with no
overlapping between reset and set voltage (1.5V, 2.5V respectively) ,also between high and
low resistance states (7.7KΩ,106Ω). Good retention and endurance are obtained and the ratio
between HRS to LRS has been found to be at least (41) within 21 cycles

Optimum Cost Design of Reinforced Concrete Columns Using Genetic Algorithms

Rabi; M. Najem; Dr. Salim T. Yousif

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 112-141
DOI: 10.33899/rengj.2014.86986

The aim of this study is finding the optimum cost design of reinforced concrete
columns with all loading conditions (axially, uniaxially and biaxially loaded) using the
Genetic Algorithms GAs. Many design constraints were used to cover all the reliable
design results, such as limiting the cross sectional dimensions, limiting the reinforcement
ratio and even the behavior of the optimally designed sections.
Each of the designed columns was handled by the GAs solver according to its
loading condition specifications. The load contour method was used to design the biaxial
sections with the adjustment of the plastic centroid. A long column constraint was
introduced to limit the design procedure with the short columns only. The optimum
results were compared with other published works, and a reduction in design cost of the
biaxially loaded columns of about 26 % was achieved using the GAs design method
while a small percent in the cost reduction
( 1 – 3 % ) was achieved for the uniaxially designed sections, while 50% was the cost
savings in the axially loaded columns. It was proved that the genetic algorithm is
capable for designing optimum columns sections despite the complex constraints that
control the designing procedure

The Effect of HARQ Procedure on the Performance of LTE System

Firas S. Al-Sharbaty; Safwan H. Fasola

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 1, Pages 123-122
DOI: 10.33899/rengj.2014.86989

In this paper, the parameters of the LTE system in DL are investigated. These
parameters include the effect of the Hybrid Adaptive Repeat and Request henceforth
(HARQ) on the Signal to Noise Ratio (SNR), Block Error Rate (BLER), and throughput.
The paper deals with three cases of Channel Quality Indicator (CQI): 3,7 and 15.The
results showed that the HARQ procedure can improve the BLER and the throughput
when the retransmission between the evolved base station (eNodeB) and a User
Equipment (UE) increased