Print ISSN: 1681-6900

Online ISSN: 2412-0758

Issue 15,

Issue 15

Heat Transfer Enhancement in a Duct with Two Right Angled Bends

Jalal M. Jalil; Talib K. Murtadha; Sanaa T. Mousa

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4889-4909

A numerical study was carried out to predict the behavior of complex flow and forced convection heat transfer characteristics in a duct with two right. angled bends for both laminar and turbulent flows. The finite differences method was employed to solve the Navier . Stokes and energy equations. The thermal boundary conditions at the duct walls are adopted by using an isothermal for laminar flow and transient heat conducted with convection for turbulent flow. The equations of vorticity and energy have been solved by using the explicit method.
The computations were performed for step height ratios (H/W=2, 3, and 4), inlet air velocities (0.12-1.0 m/s) for Reynolds number (568-33334), ambient air temperature of (30-35¢ªC), duct wall thickness of (0.002-0.004 m) and different duct metal on the behavior of the flow and heat transfer. Generally, the effect of the step ratio on the bulk temperature and local heat transfer is minor for H/W equal or greater than 3. Also, it is found that both flow and heat transfer patterns
change drastically from laminar to turbulent flows. Moreover, in the turbulent flow regime, the maximum heat transfer rates occur at increasing of the inlet air velocity and the ambient air temperature, also at decrease in the duct width and wall thickness with aluminum duct. Also, it was found that the bulk temperature tends
to reach a higher value at the duct bends (separation and recirculation regions) and lower values for the local Nusselt number. The numerical results of local Nusselt number along the duct wall for laminar flow were compared with published experiment results. The comparison indicates reasonable agreement.

Using 3D Analysis of GIS and Remote Sensing for Modeling Erbil Water Flow and Sewerage Network

Amjed Naser Mohsin

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4910-4925

Objective of this paper is to show the logical development of digital
technologies that explain and show the movement of water in two- and
three-dimensions (2D and 3D) as observed in nature. Flow of water is a
special case of fluid flow in porous media, and is governed by the laws of physics, in particular the laws of fluid mechanics. Fluid mechanics deals with the motion of fluids and with the forces The purpose of this paper is to obtain 3D digital map of flow that enable to interprets the state variables of water(superficial and ground water) in each point of the flow domain and if necessary also in time. The improper disposal of sewage is one of the major factors threatening the health and comfort of individuals in areas where satisfactory municipal, on-site, or individual facilities are not available. This paper not only shows the impact of water flow and its relationship with landuse but also illustrate the areas that out of service of sewerage network in Erbil city (study area). Modeling flow let us see how water or other materials move from a source point (or points) through a network or over a surface with aiding of GIS and remote sensing thus help
in analyzing water sources in Erbil city and understand how these water
sources used . The final 3D digital map contains all necessary information for users and designers to reach to the best decision.

Determination of the Optical Constants of Thin-Film Coating Material Using Evolutionary Algorithm

Muhammed Abdul-Redha Hussain

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4926-4938

Anew mathematical procedure depends on the evolutionary algorithm has been proposed to estimate the optical constants (refractive index, extinction coefficient and thickness) of unknown deposited material on a defined substrate. The transmittance and reflectance experimental data are taken for two materials (Sc2O2 and Rh) with two different thicknesses for the wavelengths range (400-850 nm). The resulting optical constants and the theoretical transmittance and reflectance spectra are very close to the experimental data.

Numerical and Experimental Studies of Two-Phase Flow in Cooled / and Adiabatic Capillary Tubes

Wahid S. Mohammad; Nazar F. Antwan; Zainalabdeen Hussein Obeed

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4939-4958

A numerical and experimental study was performed to predict the flow and
thermal performance of a capillary tube that used in air conditioning and
refrigeration systems. In the numerical study, the (CFD) technique was employed
to model the problem using the finite volume method for a two-phase, two
dimensional flow in the pipe. In the experimental part, an experimental rig was
constructed using a split unite to measure the temperature and pressure along the
capillary tube. These measurements were taken for (R-22) refrigerant with
different ambient temperatures. It was found that for a fixed length and diameter
of capillary tube the mass flow rate of (R-22) increases as the inlet temperature
increases. The numerical study was then applied to predict the flow and heat
transfer along several types of capillary tube, i.e. several lengths, diameters, and
refrigerants, for cooled and non cooled tube. In the non cooled capillary results,
the capillary tube length of R-407C (R-32/125/134a(23/25/52)) was found to be
shorter than that required for (R-22). It was also found that (R-22) vaporized later
than its corresponding (R-407C). The same condition was found for (R-12) and its
alternative R-134a (CF3CH2F). The numerical results show a large effect of the
length of capillary tube on the refrigeration system performance. When the length
increases, the drop in pressure, temperature, and density decreases, while the
velocity and dryness fraction increases.

New Short Term Planning and Scheduling Mathematical Model for Flexible Batch Manufacturing Systems

Alla El-Din H. Kassam; Maha Naji Ali

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4959-4969

In this paper a new approach is developed to tackle a real problem for short term production planning and scheduling work shop. A comprehensive binary mathematical model for a flexible batch manufacturing system based on the JIT philosophy and the group technology is developed. Each job is consisting of a batch of homogeneous parts and the ready time with the due date is determined. There are a number of machines in each work station process different jobs and the setup time is independent on the sequence of processing.
There are nineteen constraints imposed on the formulation of the model. Some of these constraints are relating to the number of tools available and the time required for each job not to be exceed from what was specified. The objective function is composed of three main components which expressed as a function of the profit gained by production of each job, tardiness penalty cost, and setup penalty cost. The
objective function is maximized such that the production of neither one of the jobs exceeds its demand, and also the available processing time and the tool magazine capacity at each work station are not exceeded. The developed model is tested by example which shows the effects of all model parameters and constraints. WinQSB software is used to implement the mathematical model. This research can be considered as the first attempt approach to solve a real short term planning and scheduling problem facing the advanced workshops for Flexible Manufacturing Systems.

Simulation Design of A General Purpose Microprocessor Based on FPGA

Sabah Abdul-Hassan

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4980-4991

A General purpose microprocessor is one having the capability to execute the usual set of instructions like arithmetic, logic, branching and other control instructions. It is consisting of a set of registers to store data, a program counter, a stack pointer, ..etc. In this work, a Processor system is proposed, designed, simulated using MATLAB SIMULINK, and implemented using FPGA implementation tools. The simulation is done using MATLAB because of its simple building and testing facilities. The system then implemented using Field Programmable Gate Arrays (FPGAs). The implementation using FPGAs has the advantage of being debugged, updated, expanded simply by reprogramming the FPGA chip without the need to replace the hardware. The system is implemented using two types of chips for comparison purposes. The first is using the chip VX1000 (G680) that contains 12288
slice while the second is using XCV800 (FG676) that contains 9408 slice.
Implementation results show higher percentage use of the smaller chip resources but faster operation due to shorter internal paths used

A Proposed Genetic Algorithm for Multicast Routing

Muna Mohammed Al-Nayar; Abdul Kareem Mahmod Shukri

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 4992-4999

Many Internet applications (such as video conferences) are one-to-many
or many-to-many, where one or multiple sources are sending to multiple receivers. These applications need certain Quality of Services to be guaranteed in underlying network. This paper presents a genetic multicast routing algorithm which finds the low-cost multicasting tree from a designated source to multiple destinations with Quality of Service (QoS) (i.e., bandwidth and end-to-end delay) constraints.
Experimental results show that the proposed algorithm finds the minimum-cost multicast routing tree while satisfying QoS constraints and could finally converge to the global optimal solution for a large-scale network.

Influence of Cut Out Way on the Elastic-Plastic Behavior of AL-Cu Alloy

Farag M. Mohammed; Assifa M. Mohamad; Dunia H. Escander

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5000-5013

The influence of cut out way on the elastic-plastic behavior of AL-Cu alloy was studied in the present work experimentally and numerically using finite element method with aid of ANSYS-11 software. Central circular hole were introduced in (ASTM B 557-02a) tension specimens of alloy using drill and punch at cold and warm working conditions with (3.5, 4.25 and 6) mm diameters. Based on the results from experimental tension tests, as the hole diameter increases the mechanical properties of the alloy decreases. Tensile strength and yield stress with using bunch are less than that of using drill by 4% and 6% at cold condition, while at warm working condition by 34% and 42% respectively. But the elongation at maximum tensile strength of using punch is greater than that of using drill at cold working condition and vice versa at warm working condition. The fractures with using punch happen faster than that of using drill at lower strain rate. The apparent stress concentration factor ranged from 1.19 to 2.9 with using drill, and from 1.25 to 3.39 with using punch. The numerical results present the von Mises Stress distribution to identify the location that possibly
initializes the fracture, and to estimate the stress concentration factor in which ranged from 2.13 to 2.39 and have reasonable agreement results with literatures.

Field Oriented Control For Three Phase Induction Motor Based On Full Neural Estimator And Controller

Fadhil A. Hassan

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5014-5027

Closed loop speed control for an I.M is somewhat complex strategy, the
complexity is gradually increases according to the demand performance degree. There are many types of control strategies: scalar, direct torque, adaptive, sensor less, and vector or Field Oriented Control (FOC). This paper proposes the FOC strategy in details. Rotor flux, unit vector, and electromagnetic torque estimation are considered by using Digital Signal Processing (DSP). Artificial Neural Network (ANN) becomes a powerful tool for control nonlinear system in present
time. This study proposes the using of ANN in stead of DSP to estimate the flux, unit vector, and electromagnetic torque to reduce the hardware complexity and the Electromagnetic Interference (EMI) effect. Also, it proposes the PI neural-based controller. The overall system simulation for both DSP and ANN are proposed. The performances of both systems are investigated, which give in DSP: rise time 0.24 sec, settling time 0.29 sec, overshot 5%, steady state error 0.5%. Whereas, in ANN: rise time 0.18, settling time 0.19 sec, overshot 1%, steady state error 0.2%.

Quantitative Determination of Paracetamol in Pharmaceutical Formulations by FTIR Spectroscopy

Bashar Hussein Qasim

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5028-5035

The aim of this work was to use a spectrophotometric method for the
determination of paracetamol in pharmaceutical formulations.The quantification of paracetamol through infrared spectroscopy was developed and validated for pharmaceuticals in tablet forms. The method involves the extraction of the active ingredient with chloroform and the measurement of the area of the infrared band corresponding to the carbonyl group centered at 1650cm-1. The specificity,
linearity,detection limits,precision and accuracy of the calibration curve, paracetamol extraction, infrared analysis and data manipulation were determined in order to validate the method. The statistical results were compared with the quantification of paracetamol through UVdetection.The recovery values obtained in the analysis of pharmaceuticals are within the range 98-105%.

Influence of Butt Welding Shapes Design on the Microstructure and Stresses of Low Carbon Steel

Hani Aziz Ameen; Khairia Salman Hassan

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5036-5047

The aim of this paper is to demonstrate the influence of butt welding shapes on the microstructure, temperature and equivalent stresses of carbon steel type St- 37.The single butt welding was performed by V angles 15°,30°,45° and U shape. The finite element analysis via ANSYS software is performed , this analysis includes a finite element model for the thermal and mechanical welding simulation. The equivalent stresses and temperature distribution were obtained. From the results of the microscopic structure it is evident that the geometric shape
has an important role in the welding process, when the geometric value of the welding region gets bigger, the faults get less due to increase of heat quantity in the welding region. The work presents the finite element model for numerical simulation of welding stresses in carbon steel St-37 butt welding. The welding simulation was considered as a direct coupled thermo- mechanical analysi.s

Charpy Impact Value of Friction Stir Welded 7020 and 7075 Aluminium Alloys at Different Tool Rotation and Transverse Speed

Shawnim R. jalal

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5048-5054

In this work, the effect of friction stir welding parameters such as tool rotation and tool transverse speed on the impact value of 7mm thick weldments of aluminum alloys 7020 and 7075 each alone at T6 and T9 temper conditions has been studied and investigated. Three tool rotation speed (280, 580, and 960 rpm) and five tool transverse speed (36, 76, 102, 146, and 216mm/min) were selected for the friction stir welding of each alloy condition. The resistance of weldments to
sudden loading has been investigated using the Charpy impact test with standard V
– notched specimens at room temperature. It has been observed during this work that the total impact energy increased in the friction stir welding of (medium strength) 7020 Al alloy for both temper conditions especially at 580 rpm and 102 mm/min with respect to the base metal while rotation and transverse speed have little effect on the impact value of (high strength) 7075 Al alloy and the results were very close to each other. Finally it is important to mention that the relation
between rotation speed, transverse speed and input heat which affect on the impact value seems to be complex and depend on the material properties being welded.

The Effect of Shot Peening and Residual Stresses on Cumulative Fatigue Damage

Hussain J. M. Alalkawi; Qusay Khalid Mohammed; Waleed Sadun Al-Nuami

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5055-5070

A series of constant and cumulative fatigue tests under the effect of shot peening were conducted for two aluminum alloys 2024 and 5052. Three unpeed specimens were tested for each alloy under low-high stress levels (120-280 MPa) for 2024 aluminum alloy and (40-90 MPa) for 5052 aluminum alloy at room temperature and stress ratio R= -1. Other specimens were exposed to shot peening with different blasting time before the cumulative fatigue testing. It is found for 2024 Al alloy that as the shot peening time increases the cumulative fatigue life is improved but above 10 min. the life is reduced. For 5052 Al alloy the cumulative fatigue life is reduced as shot peening time increases

Unscented Kalman Estimator for Estimating the State of Two-phase Permanent Magnet Synchronous Motor

Ayad Qasim Hussein

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5071-5078

This paper presents the unscented Kalman filters (UKF) for estimating the states (winding currents, rotor speed and rotor angular position) of two-phase Permanent Magnet Synchronous Motor (PMSM). The UKF is based on firstly specifying a minimal set of carefully chosen sample points. These sample points completely capture the true mean and covariance of the Gaussian Random Variable (GRV), and when propagated through the true nonlinear system (motor model), capture the posterior mean and covariance accurately to the second order (Taylor series expansion). The results showed that the UK estimator could successively estimate the states of PMSM without need any Jacobian matrix.

Design and Implementation of An Intelligent Traffic Light System

Hadeel N. Abdullah; Ivan A. Hashim; Bassam H. Abd

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5079-5087

The main object of this paper is to design and implement an intelligent
traffic light system. The system is able to sense the presence or absence of vehicles within certain range, by setting the appropriate duration for the traffic signals to react accordingly. The simulation of the intelligent traffic signal system is done using Electronic Work Bench Package (EWB). The new timing scheme promises an improvement in the current traffic light system. This system is feasible, affordable and ready to be implemented especially during peak hours

Evaluation The Performance of Al-Thawra At-Grade Intersection Using The HCS2000 Computer Package

Ali Majeed K.Al-Ubadiy; Zeena Tariq Al-Azzawi; Nawal Dawood S

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5088-5101

Al-Thawra signalized intersection is one of the most important intersections in AL-Hilla city because it relates the Governorates: Baghdad, Najaf, Kerbala and Babel, and serves of about 21000000 passages of vehicles yearly. The excessive traffic volumes, during the peak periods (at morning and evening), of vehicles that entering the
intersection increase traffic density, reduce travel speed, increase travel time, and increase the delay values. The delay values are reflected by McTrans Center, University of Florida {Highway Capacity Manual (HCM2000)} to an indicator named LEVEL OF SERVICE (LOS). The operational analysis of the existing conditions of this intersection
by the Highway Capacity Software (HCS2000) indicates that the LOS of it equal to (F) with an intersection delay value of 263.7 sec./vehicle and a degree of saturation exceeds 1.5. Therefore, and because of the reasons above, it is important to improve the performance of Al-Thawra Intersection by separate the conflicting traffic movements
with an overpass bridge. The traffic survey shows that the high traffic volume of through movement of the North-South direction (Baghdad-60St.) has the major effect on the intersection. Therefore, the North-South is the suitable direction to construct the suggested bridge overpass to separate the through traffic of this direction (from Baghdad
to Najaf {60 St.} and vice versa) from the other movements of the intersection. The results indicate that the intersection LOS equal (C) with a cycle time of (58) sec. and an intersection delay of (22.8) (sec./veh.) at the object year 2027.

Using B+ Tree To Represent Secret Messages For Steganography Purpose

Suhad M. Kadhem

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5102-5112

In this research we suggest a new approach by using B+ tree for storing the secret massages (that want to be sent) in a manner that prevent redundancy of these massages or even sub massages in order to provide efficient memory usage . The proposed system includes two stages: Stores the secret message and get its unique code by using B+ tree, and retrieves the unique secret message when we have its code by using B+ tree. The proposed system was implemented using Visual Prolog
5.1 and after testing, the proposed system gives an efficient time in storing and in retrieving the secret messages, also the proposed method solved the ambiguity problem that some steganography methods suffer from.

Finite Element Analysis of Single Sided Linear Induction Motor

Adil H. Ahmad; Mehdi F. Bonneya

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5113-5123

This paper presents analysis and operation of linear induction motor (LIM) using finite element method (FEM). The solution of magnetic field problem is performed for both two and three dimensional approaches. Magnetic vector potential, flux density, field intensity, induced rotor current, and propulsion force are computed for LIM model studied. The effect of velocity is taken into consideration. The primary winding self and mutual inductances are computed for three dimensional analysis.

Experimental Study of The Effect of Addition of Calming Section on The Heat Transfer Process In A Uniformly Heated Inclined Tube

Nasser F. Hussain; Abdulhassan A. Karamallah; Akeel A. Mohammed

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5123-5137

Experimental research has been conducted for combined convection to study the local and average heat transfer for hydrodynamically fully developed (the value of L/D of calming section was 22.2) and thermally developing laminar air flow in a uniformly heated inclined tube. The study covered a wide range of Richardson number (Ri) from 0.08 to 2.5, Reynolds number from (518 to 2041), and Rayleigh number from (2.4~105
to 3.9~105), with different angles of inclination {ƒ¿= 00 (horizontal), }300, }600, }900 (vertical)} where the minus sign refers to opposing flow and plus sign refers to aiding flow. An empirical correlations were made for the average Nusselt number as a function of Rayleigh number and Reynolds number for all angles of tube inclination
and compared with another correlations from previous works. Results show that the heat transfer process for low Richardson number is better than that for high Richardson number and the values of average Nusselt number (Nu ) increase as Peclet number (Pe) increases for the same Rayleigh number.