Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 28, Issue 16

Volume 28, Issue 16, August 2010, Page 767-5388


Control of Separation For NACA 2412 Airfoil At Different Angles of Attack Using Air Blowing

Jalal M. Jalil; Assim H. Yousif; Yasser Ahmed Mahmood

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5138-5150

The study of the separation control using the jet blowing based on the
computation of Reynolds-average Navier-Stocks equations is carried out in this work. A numerical model based on collocated Finite Volume Method is developed to solve the governing equations on a body-fitted grid, to compute the performance of airfoil by using the blowing jet. Above of all, the performance of turbulence model is investigation. A revised k-ƒÖ model is proposed as the known turbulence models perform well in reproducing the flow of airfoil at pre-stall or stall angle of attack. The systematical investigation of the jet blowing is conducted
on the NACA 2412 airfoil in the range of attack angle from 0o to 30o included up and beyond the stall angle at range of Re=3.4*105-1.7*106 . The influence of some parameters associated with using jet blowing, such as its location, and the speed ratio (Uj/U) strength on the performance of the NACA 2412 airfoil has also been studied. The result shows that the jet blowing is effective in controlling the separation at 0.3C and Uj/U=2. The large separation regions cannot be completely
removed by the jet blowing. However, the flow structure can be regularized. The lift coefficient of the control airfoil is also increased with the angle of the attack. The experimental results are obtained on airfoil NACA 2412 at 0.3C blowing and Uj/U=2, the results are been good agreement with the computational results.

Laser Surface Treatment for Anodizing Process of Aluminum Alloy

Ali.A.Abdul Hadi

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5151-5164

Laser material processing play important role to improve surface properties, in this work Aluminum AA1100 was used to build Al2O3 oxide layer on the main surface of the workpiece in H2SO4 acid at cell potential between 8-24 volts for 30 minutes after irradiated the surface test by pulsed Nd-YAG laser, fluctuating current was
measured with time without laser treatement and after laser treatment, Pulsed Nd- YAG laser was used to test the resistance oxide layer to break. This paper gives results of the experimental research referring to the quality of surface indicator obtained by laser surface treatment.

Study of The Wear Rate of Some Polymer Materials In Different Conditions

Awham M. H; Sadeer M. M; Bushra H. M

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5165-5170

The current investigation is interested by study of the wear phenomenon for two polymeric materials (Epoxy and Unsaturated polyester) resins, the prepared specimens were tested at room temperature by using two different loads(10,20)N for various testing times with different sliding distances. The resulted wear rates were calculated for each sample apart with. Variation the previous variables. To produce more precise idea about the wear characteristics of both above materials when immersed them in water environment, the study of wear rates was carried out for different immersion times at different temperatures when the above mentioned variables were fixed. It was found after comparing the results which obtained from the wear test in air that
Epoxy resin undergoes higher wear rates than unsaturated polyester resin in general with variation the testing parameters, while the results of immersion in water which acts as plasticizing factor for polymers exhibited different effect on the wear behavior of the materials under study.

Active Magnetic Bearing Design Optimization and Transient-State Analysis Using ANSYS

Adil H. Ahmed; Thamir M. Abdul Wahab

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5171-5187

This paper presents design optimization, and transient-state analysis of
active magnetic bearings (AMB) using the powerful ANSYS software package.
ANSYS software provides the required environment for numerical modeling and
analysis based on the finite element method (FEM). In this paper two programs
are developed in ANSYS, the first for modeling and optimizing the analytically
designed active magnetic bearing, and the second for transient-state analysis of the
FE model to investigate the effects of eddy currents on the considered active
magnetic bearing.

Analysis and Simulation of Shunt Active Power Filter For Harmonic Cancellation of Non Linear Loads

Ahmed M. Mohammed

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5188-5199

Use of nonlinear loads, such as power converters, power sources,
uninterruptible power supply (UPS) units, and arc devices like electric furnaces and fluorescent lamps and large adjustable speed motor drives, is expected to grow rapidly. All of these loads inject harmonic currents and reactive power into the power system. This paper presents a study and simulation of a three phase active power filter. A multilevel PWM inverter is used with current control technique. The proposed control system is very simple and therefore practical
implementation of active power filters is available. The presented system is able to compensating current harmonics, reactive power and unbalance current of non linear loads. The total harmonic distortion is calculated for deferent load before and after filtering with deferent type of filter. A comparison is made between passive filter and active.
The results have been obtained using software called PSIM, which has
demonstrated its reliability for almost 10 years of simulations, which have been approved with real experimental results.

Impact Resistance of Lightweight Chopped Worn-Out Tires Concrete

Zaid M. K. Al-Azzawi; Dhafir T. F. Al-Khameesi

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5200-5212

This study summarizes results of an experimental investigation of the
impact resistance of 12 lightweight concrete slabs made from incorporating chopped worn-out tires (Ch.W.T.) into the mixes as a partial replacement of the sand in mortar mixes, and as partial replacement for both sand and gravel for concrete mixes; volumetrically.
The main variables were; the partial replacement ratio (PRR) and the shape of the falling mass (striker). Data were obtained pertaining to compressive strength, static and dynamic modulus of elasticity, and modulus of rupture. In addition, the crack pattern under impact loading was studied to provide insight into the internal behavior and failure mechanism of lightweight Ch.W.T. concrete slabs. Results of this work indicate that incorporating Ch.W.T. into mortar and concrete mixes succeeded in reducing its unit weight from 17.9% to 26.2% according to type of mix and partial replacement ratio. In contrast, the ultimate
impact resistance, expressed in the number of blows required for complete separation of the specimen, increased from 91% to 186% for mortar mixes depending on the partial replacement ratio and the type of falling mass; and did not decreased significantly for concrete mixes.

Remote Sensing Model for Monitoring Trophic State of Al Huweizah Marsh

Abdul Razzak T. Ziboon; Riyadd Z.Al Zubaidy; Mahmoud S. Al Khafaji

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5213-5222

Remote sensing techniques were used to monitor the Trophic State Index
(TSI) within Al Huweizah Marsh. The TSI is a function of Secchi depth (SD), which is a function of the spectral reflectance in Blue (TM1) and Red (TM3) spectrum bands. Satellite images of Landsat-7 ETM for February and March-2006 were selected and a series of remote sensing and digital image processing techniques and methods were applied on the selected images to extract the required data from these images. A set of measured SD and obtained spectrum reflectance from the Landsat ETM image of February-2006 were used to perform the calibration process by using the quasi-Newton optimization method. The calibrated model was applied on the marsh area by using the two selected images.
Results of applying this model show that the TSI values in most of the Iraqi parts of the marsh are between 40 and 50% and increased in the Iranian and the southern part of the marsh to about 70%. The developed model can be effectively used to estimate the TSI distribution pattern within the marsh.

An Effective Wireless Monitoring Tool (EWMT)

Afnan Adil Abd Alraheem; Shaimaa H. Shaker; Mumtaz M. AL-Mukhtar

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5223-5237

As computer networking has expanded and matured, there has been a growing requirement to collect traffic statistics for understanding the current load and planning future connectivity. This requirement leads to consider the general problem of a software packet monitor for analyzing traffic patterns and gathering statistics. This Paper presents a software monitoring system named "Effective Wireless Monitoring Tool" (EWMT) which has been built to help the network administrator to discover network problems as soon as possible.
The proposed system achieves its goal by sniffing, capturing, and
analyzing the network traffic data packets using a passive monitoring
scheme without affecting or interfering with the network information flow. This is achieved by configuring the Network Interface Card (NIC) in promiscuous mode. The EWMT extracts and views different valuable
detailed information concerning the network in human- readable format. It taps network protocols that run at the IP level, TCP level and other
protocols at the application level as DNS, HTTP, and FTP. EWMT system is constructed using Microsoft Visual C++ V8.0 development environment along with 3.5.NET framework

Studying Some Of Mechanical properties Of (sawdust/Un Saturated Polyester) Composite in salt solution

Sanaa A. A. Hafad

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5238-5245

Commercial sawdust is the most common wood filler used for polyster
thermosetting and is produced from graduated particles of different sizes which has in general has a lower aspect ratio than wood and other natural fibers. Wood additives include a mixture of sawdust and short chopped fibers. To study how characteristics of fibers and sawdust influence the mechanical properties of unsaturated polyester composites .Investigations were made by studying the effects of different volumetric fractions from sawdust and fiber fillers (up to limit
of 1.4mm), then these results were compared with the properties of sawdust –fiber filled composites immersed for different periods in a salt solution of (2 N) . wood volume fractions {(20, 30, 50) vf %} selected to be added for un saturated polyester were studied which gave improvement in their selected studied mechanical properties for all reinforced composites -(only impact is decreased)- and particularly at higher values of volume fractions ,were hardness showed an improvement by (15% ) , compressive strength gave obvious Improvement by
(38% ) ,while impact resistance decreased by (16%) with the reinforcement of (50 vf %) sawdust . The above values were reduced when the items were immersed in asalt solution for (60days).

Dynamic Analysis of Gough-Stewart Platform Manipulator

Muhsin N. Hamza; Hassan M. Alwan

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5246-5255

A novel derivation to evaluate all the controlled forces which cause by the motors and effected along the prismatic joints on the legs of the Gough-Stewart platform manipulator based on the virtual work method is proposed in this paper. In this paper the manipulator can be considered as a multibody mechanism with rigid elements. It can be assumed that the manipulator motion was known. The aim of the dynamic analysis in this paper is to evaluate all the controlled forces which necessary to implement the manipulator programming motion

Analysis Frequency Modulation Mode-Locked Fiber Laser by Using ABCD Rule

Jassim Kadim Hmood; Bushra R. Mahdi

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5256-5270

In this paper the study of Frequency Modulation (FM) mode-locking fiber laser is presented. The time-domain ABCD law was employed to clarify the impacts of optical elements on the mode-lock pulses. ABCD matrices formalism in the time domain has been developed under a Gaussian paraxial approximation. Also, these matrices apply to the theory of the actively mode-locked fiber laser. The numerical results are obtained by using MATLABÒ software. The analysis was produced a shorter than 3.16ps duration pulses in laser mode locked with FM modulator driven at repetition frequency of 10GHz and cavity has anomalous dispersion of -
0.015ps2/m and nonlinearity of 0.02W-1m-1. The values of chirp are plotted versus average power with many values of dispersion. All relationship between the pulse laser parameters and other effective parameters like, second order dispersion, nonlinearity, average input power, repetition frequency and optical filter bandwidth are plotted and
discussed

A Numerical Model For Performance Prediction Of Dry Cooling Conditions Of Air Cooled Condensers In Thermal Power Plant Stations

Ali Hussain Tarrad

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5271-5291

The present work represents theoretical treatment of dry cooling of the air cooled condensers applied in the power plants technology. A suggested model was built in a form of computer program to predict the effectiveness of the condenser showing the effect of inlet air temperature and its mass flow rate on the performance of the condenser. The model construction depends on the idea of using a row by row marching solution for energy balance for both stream sides.
The model has the ability to estimate the heat transfer coefficient, air temperature and other air physical properties distribution in the air flow direction from row to row. The results showed that using the cooling process of the air before entering the condenser improves the performance of the condenser and reduces the required area for a specified condensation load and steam loading. For fixed surface area of
the condenser, lowering the dry bulb temperature from (45) to (28) ºC at a constant wet bulb temperature and mass flow rate of the entering air can improve the condensation load up to (23 %) for the present investigated conditions.

Design An Expert System To Detect The Errors In Logic Circuits

Eman Yousif Nasir

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5292-5309

An expert system is a computer program designed to simulate the problem-solving behavior of a human who is an expert in a narrow domain or discipline. An expert system is normally composed of a knowledge base (information, heuristics, etc.) and inference engine (analyzes the knowledge base), and the end user interface (accepting inputs, generating outputs). One of the attractive features of expert systems is the program's ability to review a consultation and provide the user with an explanation for how its conclusion was derived. In this research, the expert system is used to detect the errors in logic circuits. The program is written in visual basic programming
language depending on the truth table of logic gates so that the user doesn't need to save these truth tables in his mind. This program is applied in combinational logic circuit, which doesn't contain feedback. The program is answered for the questions of user "Why" and "How" to provide the description and details about gates and their works.

Effect of Current Density And Heat Treatment on The Electrodeposited Nickel Coated Bulk Graphite

Salam H.Al; Sabah M. Ali Radha; Farah A. Abed

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5310-5316

In this work , a bulk graphite substrate was coated with nickel using
electroplating technology. The reason of this work is to remove the oxidation characteristics of graphite at intermediate temperatures in the range 450 – 500 °C. The experimental facilities were locally designed and developed . The visualization of the coating topology showed the effect of current density on the microstructure of the electrodeposited layers. The grain size tends to be smaller as the current densities are increased . The effect of heat treatment
on the microstructure showed an encouraged grain growth which was
greater at high treatment temperature .

Design of Low Dispersion Flattened Optical Fiber

Alaa Hussein Ali

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5317-5326

Dispersion of the transmitted optical signal causes distortion for both digital and analog transmission along optical fibers. When considering the major implementation of optical fiber transmission which involves some form of digital modulation, then dispersion mechanisms within the fiber cause broadening of the transmitted light pulses as they travel along the channel. This paper demonstrates that non-zero dispersion flatting optical fiber is achievable with dispersion extended over
more than spectral range of 300nm. A total dispersion of (0.0398444 ps/nm.km) is obtained due to a design of an optical fiber with triple-clad at wavelength of 1551nm. Also the flatting optical fiber is tested using computer simulation at two distances at 50km and 100km.

Practical Application For Designing Quality House (Case Study)

Khalil I. Mahmoud; Zainab K. Hantoosh; Muslih Abdullah

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5327-5345

Quality Function Deployment (QFD), as came in definition ,is a
systematic thinking process for product planning that enables businesses to consider the characteristics of product to ensure that products satisfy customer requirements for it is a customer –driven quality management and product development system for achieving higher customer satisfaction . (QFD) has become a widely used tool in the product development process. It helps design teams gather the wants and needs of the customer and organize and utilize this data so that a product which satisfies the customer will be developed. It addresses
dimensions including customer desire, quality characteristics, functions, parts, and failure modes. One of the reasons for the success and acceptance of QFD is that it is a very versatile tool. The traditional matrices and process can be modified in many different ways to fit the needs of the product team. Like any innovation, however, QFD in practice has been implemented with varying degrees of success.
QFD is a system engineering process, which can be applied to large systems. It can be extended to a project functions, project phases, project resource utilization, and other areas such education. QFD utilizes the house of quality (HOQ) as a method of understanding customer requirements, establishing the priorities of design requirements, and product segmentation and positioning. The research presents how to build the house of quality through a real case study.
The aim of this research is emphasis that such techniques should be strongly considered for inclusion in any Total Quality Management effort and specially can be applied to practically any manufacturing or service industry. So we applied the new techniques even in representing the House of Quality matrix by using Auto Cad program. that we consider an electrical motor (1/4 HP) in our case study because of its wide use, especially at summer season in the air coolers, by consulting the specialists from engineers and technicians especially in our field
“Mechanical Engineering” as well as consumers by the huge field study in
industry as well as markets with focusing on some main customer requirements, then comparing our results with other foreign products.
In short the organizations should recognize such tools and techniques in the context of total Quality Management in order to increase the knowledge and personal efficiency. as we concluded in our case study by taking many different variables.

Numerical Modelling of Transient Flow In Long Oil Pipe Line System

Shaker H. Aljanabi

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5346-5364

The problem of unsteady flow are frequently encountered in long oil
pipelines without the provision of surge tank due to sudden closing or
opening of valve and pump trip. The oil-hammer are analyzed and
predicted by using the Eulerian approach (MOC) and the Lagrangian
approach (WCM). The investigation was carried out for sufficiently long
time to demonstrate changing of pressure head with time. Transient
conditions arising in long oil pipeline with pumping station, valve and
branches are studied in details for KRK pipeline by these two pproaches.
A Computer programs for all these components were developed.The effect of valve closure, line branch junction and pump shut-down are studied taking into account the effect of line friction on pressure wave. A
numerical model "UNSTEADY_ FRIC_WH" using MOC and Barr's explicit friction factor has been presented for solution of the transient flow
situation of water hammer. Assessment of friction factor at any section in this unsteady transient flow conditions clearly indicates the effectiveness of using variable friction factor in contrast to the steady state friction as in the available numerical models.

Effects of Nano-Fluids Types, Volume Fraction of Nano-Particles, and Aspect Ratios on Natural Convection Heat Transfer in Right- Angle Triangular Enclosure

Israa Y. Daood

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 5365-5388

This study investigates natural convection heat transfer and fluid flow
characteristic of water based nano-fluids in a right-angle triangular enclosure, where the left vertical wall is insulated, the right inclined wall is cooled, and the horizontal wall is heated by spatially varying temperature. Governing equations are solved using treamvorticity
formulation in curvilinear coordinates. Streamlines, isotherms, local and average Nusselt number, moreover to NUR factor are used to present the corresponding flow and thermal fields inside the triangular enclosure. Calculation were performed for three aspect ratio of enclosure geometry (AR=0.5, 1, 2), solid volume fractions of nanoparticles ranging from PHI=0, to 4%, and Rayleigh number varying from 104 to 106. Three types of nano-particles are taken into consideration: Cu, Al 2O3, and TiO2. The results show that, the average heat transfer rate increases significantly as particle volume
fraction and Rayleigh number increase. Also, the type of nano-fluid is a key factor for heat transfer enhancement where the high values are obtained when using Cu, TiO2, and Al2O3 nano-particles respectively. Finally, it is observed that the aspect ratio of the enclosure is one of the most important on flow and heat transfer. Increasing the AR leads
that to increase the flow strength and heat transfer rate.

Study of the Prodigiosin productivity from Serratia marcescens isolated from environmental and clinical sources and the effect on some microbial pathogens

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 767-771

The Prodigiosin pigment was purified by using the organic solvents
chloroform and methanol with thin layer chromategraphy method. The biological activity for prodigiosin pigment was studied on the Staphylococcus epidermidis ,Staphylococcus aureus bacteria in in vitro tests , it has shown highly degree of inhibition, also the in vivo tests showed that clearly inhibition in animal model.

Vibration Analysis of Exhaust Gas Silencer

Engineering and Technology Journal, 2010, Volume 28, Issue 16, Pages 772-798

This research presents an analysis of the vibration of exhaust gas silencer , assuming that the silencer is mainly consisting of a porous pipe of 0.042 m outer diameter , 0.0006 m thickness and 0.8 m length , surrounded by a cylindrical casing of 0.1325 m outer diameter , 0.001 m thickness and 0.53 m length , and the tail pipe is of 0.13 m length , taking in consideration that the silencer is fixed from one end and
free at the other end . The system is assumed to be made up of two simple beams connected together by number of springs . The rubber fastener (hook) which support the casing is modeled as an elastic spring . Each of the porous pipe and the casing are divided into (30) node and (29) element along the system The method of transfer matrices is adopted to simulate the vibration of the silencer , the dynamic characteristics , i.e. (deflection , slope , shear force , bending moment) as well as velocity , pressure and temperature are post-processed for each node . It is shown that the casing exerts a considerable influence upon the response of the pipe , and system natural frequencies are highly affected by the interaction effects
between the casing and the pipe . The results show that the transfer matrices method is a powerful technique to compute the eigen modes in addition to the natural frequencies of vibration systems. The theoretical study is also show that the rubber fastener (hook) has a considerable influence upon the system because some values of the rubber stiffness leads to reduction the amplitude of vibration and also the other values of eigen modes which is make the dynamic behavior of the system much better.