Print ISSN: 1814-6120

Online ISSN: 2311-8385

Volume 14, Issue 2

Volume 14, Issue 2, Autumn 2014, Page 1-263

A Numerical simulation of emissions of pollutants from industrial chimney

Saleh I. Najim; Qais A. Rishack; Alaa H. Mohammed

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 1-12

The prediction of the concentration fields of pollutants released to the atmosphere is a key factor in assessing possible environmental damages caused by industrial emissions. To solve the concentration equation for gaseous or particulate effluents it is necessary to know as accurately as possible the velocity field and turbulence intensities at the atmospheric boundary layer in the region of interest. A two dimensional mathematical model based on the equations of fluid mechanics along with a modified non-isotropic k-ε turbulence model are employed to calculate the flow and dispersion at the atmospheric micro scale (distances of the order of kilometers).
Results of investigation are obtained by using the finite volume method (FVM) to solve the average Navier Stock equations coupling with turbulent k- ε model. The calculation was carried out for plume flow from the industrial chimney with different plume velocities, wind velocities and heights of stack. The equations of model are solved with SIMPLE schemes.
FLUENT program used to show the results of the plume flow at the variable parameters of wind and plume velocities and heights of stack, the code is applied to simulate several cases of flow and dispersion. Comparisons against experimental results show that the non-isotropic turbulence model has better ability to foresee the plume dispersion than the standard k- ε, in which the non-isotropic character of turbulence is relevant. The computational results show that the plume path and concentrations are correctly predicted by the numerical model

An Optimization-based Approach for design Ion Exchange Treatment Unit

Zohul A. Hadi Hamza

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 13-22

The objective function is to satisfy certain constraints and achieve minimum capital, maintenance, and operation costs. Ion exchange unit was used in this study. This study includes development of computer program for advanced wastewater treatment plants design adopting genetic algorithm. The program was developed using Matlab software.
The output of the genetic algorithm includes the finding of optimum design criteria for advanced wastewater treatment plants. The obtained design criteria are satisfying the required effluent quality with minimum treatment cost.
Based on results of applying GA on ion exchange treatment plant, it was found that the optimum values of bed depth, service flowrate, regenerate flowrate, and back wash rate are 0.71m, 25m3/, 8 m3/, and 55 m/hr respectively.

Application of Earth Tube Heat Exchanger and Solar Chimney for Natural Cooling System in Basrah City

Salman H. Hammadi; Alaa Hlaichi Mohammed

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 23-32

Solar chimney (SC) together with earth to air heat exchanger (EAHE) is being employed as a low-energy consuming technique to remove undesirable interior heat from a building in the hot seasons. A numerical program "FLUENT 6.3 code" of an earth to air heat exchanger (EAHE) is studied for predicting the outlet air temperature and cooling potential of these devices in Basrah climate. Theoretical analyses have been conducted in order to investigate the ventilation in a solar chimney. The investigation into the viability of Low Energy Earth Pipe Cooling Technology in providing thermal comfort in Basrah. The demand for air-conditioning in buildings in Basrah affects the country escalating energy consumption. Therefore, this investigation was intended to seek for an alternative passive cooling to air-conditioning. The passive technology, where the ground was used as a heat sink to produce cooler air, has not been investigated systematically in hot and humid countries. A sub-soil temperature model adapted for the specific conditions in Basrah is presented and its output compared with CFD modeling. The results have shown that the potential of Earth Pipe is providing lower output temperature of air inlet to the room. We found that the resulting temperature at the buried pipe outlet decreases with increasing pipe length, decreasing pipe diameter, decreasing mass flow rate of flowing air in the pipe and increasing depths up to 4m.

Compensating the End-Effector Position of Semi-Flexible Robot Using Smart Structure Technique

Hussein M. Al-Khafaji; Muhsin J. Jweeg

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 33-42

This study proposed the using of a smart structure principle with a methodology for reducing the difference (error) between the actual position (for a semi-flexible robot) and the theoretically calculated position (for a rigid robot) on-line. The methodology depends on the interfering between the maps of the two cases; the rigid case (ideal), and the deformed case (actual) for compensation of error. According to this methodology, a class (program) was built using the visual Basic.Net; this class is called the compensation class. In this work, a two degrees of freedom articulated type lightweight semi-flexible robot was used. This robot is confined to move in a vertical plane. The smart structure system was represented by; the sensors for measuring the error deformation variables were mounted on the two links of the robot, Data acquisition (DAQ) system and the actuators of the joints. The smart structure robot systems were designed and built in this work. Also, to control the smart structure robot’s systems, software was built using Visual Basic.Net. Compensation tests have been achieved on the complete system to check the performance and results of the compensation system. This system showed a good improvement in the performance of robot for compensation and reduction in the error between the ideal position (rigid robot) and the practical position (measured position). The average error after the compensation reduced to 12.32 times in the x-direction and 21.76 times in the y-direction.

Effect of Die Angle on Stress Distribution in Extrusion Process of Aluminum Rod

Rafid Jabbar Mohammed

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 43-50

Type of metal flow and stress distribution in metal extrusion process is a highly complex for the complicated die design. In this work a finite element simulation of Al-1100 rod extrusion was successfully achieved using the commercial finite element code Deform-3D.The results show that the finite element model was successfully simulate the stress distribution in the direct rod extrusion of Al-1100.Besides that the optimum die angle reduces the magnitude of normal, shear, and effective stresses. We can conclude from this studythat maximum stresses occour when the rod is with contact with the die at exit stage.

Effect of the Central Radial Groove on the Bearing Pressure Distribution Based on the Artificial Neural Network

Hussein Sadiq sultan; Maher A. Khalid; Imad Abdul-Kadhem

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 51-55

An experimental study has been implemented to study the effect of the central radial groove on the bearing pressure distribution. This study is based on the artificial neural network in the prediction of the complex and uncertain positions. Both width and depth of the groove have been varied at some magnitudes in order to investigate their effects on the pressure distribution and the stability of the bearing. Also, the effect of the groove parameters on the noise at the bearing situation in the systems have been analyzed and discussed. The results show that the use of neural network in the prediction of some points with range is very powerful in the minimization of the overall cost of groove design.

Electrode Consumption Simulation for Shielded Metal Arc Welding in Virtual Welding Training System

Raheem Kh. Al-Sabur; Qais A. Rishack

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 56-61

One of the major problems in industry are new welding trainees cost, it drains the budget of many companies, particularly in industrialized countries, through raw material costs for preparation, welding wires, electric and fumes in addition to time spent. Recently a new technique was appeared; it is called virtual welding training system (VWTS) to reduce the training cost. In the present work a VWTS technique was built, a simulation of electrode motion is upgraded by using LVDT to represent the welding arc length while a DC motor with gearbox connect to the steel rode is used to represent welding electrode consumption. A 2D graphs with touch screen monitor are used to represent welding process. All sensors were calibrated to generate a VWTS. Accepted results obtained in training new welding trainees in the shielded metal arc welding (SMAW) training.

Enhancements of mechanical properties of friction stir welding for 6061 aluminum alloy by Friction Stir Processing (FSP) method

Ali A. Salman; Ayad M. Takak; Kadhim K. Resan

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 62-66

Friction stir processing is a new method of changing the properties of a metal through intense, localized plastic deformation ,this process mixes the material without changing the phase (by melting or otherwise) and creates a microstructure with fine, equiaxedgrains, It is used to improve the microstructural properties of metals.
In this paper, the enhancement of mechanical propertiesof friction stir welding specimens at variable rotation speeds (1100, 1300 and 1500 rpm) with constant feed speed (60mm/min) for 6061-T6 aluminum alloy is studied by using the friction stir processing method at the same variable rotation speed and feed speed in order to transform a heterogeneous microstructure to a more homogeneous, refined microstructure.
The best results of the welding line at the parameter 60 mm/min weld speed and 1300RPM rotation speed for the friction stir welding (FSW) and friction stir processing (FSP) where the efficiency reaches to 84.61% for FSW and 89.05% for FSP of the ultimate tensile strength of the parent metal.

Evaluation of the Performance of Steel in Reinforced Concrete by Electrochemical Methods

Dhia C. Ali; Nawal J. Hammadi; Enas M. Manea

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 67-76

The effect of different dosages of the high range water reducing admixture–additive- (HRWRA), the commercially polymeric material (Plastocrete-N), on the corrosion resistance of embedded steel in concrete exposed to chloride solution in the absence and presence of sulfate ions was studied. In the present study, four levels of polymeric material (Plastocrete-N) (0.125%, 0.250%, 0.375%, and 0.500% by weight of cement) were used to prepare HRWRA treated concrete. The concrete specimens exposed to chloride and chloride–sulfate solutions at concentrations of (3.5% NaCl and 5% Na2SO4), at ambient temperature. The electrochemical behavior of steel in both reference and HRWRA concretes was studied under the effect of corrosive environments using corrosion measurement systems such as: a) half – cell potentials measurement system and b) accelerated corrosion test system. The results showed that a longer time of corrosion initiation (180 day) observed with 0.500% HRWRA containing concrete compared to other different HRWRA percentage including the reference concrete. It was concluded that the use of 0.500% HRWRA provided superior protection to steel reinforcement in concrete that subjected to corrosive environments. Furthermore, the steel with 0.500% HRWRA was subjected to corrosion test by mass loss, it is evident that a reduction in mass loss by about 90.2% and 85.2% in both solutions, respectively.

Experimental Study of Thermal Bubble Pump

Safaa H. Faisal; Abdulwadood S. Shihab; Saleh E. Najim

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 77-90

In this study, a numerical investigation has
been carried out for single phase flow behavior for thirty six
internally finned tubes to demonstrate the effect of axial pitch
to fin height ratio (p/e) for 0.8≤p/e≤6.345, helix angle of
internal fins (β) for 30°≤β≤70°, apex angle of internal fins (α)
for 0°≤α≤53.13°, internal fin height (e) for 0.6mm≤e≤1.0mm,
internal tube diameter (di) with 14 mm and Reynolds number
(Re) of single phase flow for 10000≤Re≤50000 on enhancement
of forced convection heat transfer and reduction of friction
factor by using ANSYS CFX program. It solves the threedimensional
Navier-Stokes equations for steady state turbulent
with SST model and enhance wall treatment. The numerical
analysis provided at fully developed velocity and temperature.
Numerical results showed that the smallest axial pitch to fin
height ratio (p/e) =0.8 and with apex angle α=10 degree
provided enhancement of heat transfer of 2.8 to 3.55 times
higher than of smooth tube. Finally, present numerical results
are seen to be in good agreement with literature experimental

Finite Element Simulation of Deep Drawing Parameters Effects on Cup Wall Thickness


Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 91-98

The present research aims to predict the thickness distribution of a wall of a deep drawn cup. A simplified 3D axisymmetric model which represents the deep drawing set (blank and tools) was created using a CAD software, and then imported into a finite element code ANSYS where a simulation was carried out. The model represents a cylindrical cup made of low carbon steel sheet. The results showed that the FE model represents real deep drawing process fairly well. The cup thickness distribution values showed a good agreement with the referenced values, where the failure or success of drawing process could be predicted based on the obtained thickness results. It was observed that a high value of friction restrains material movement and resulted in producing more thinning and more punch force. High blank holder force was found to decrease the thickness of both the bottom face of the cup and the flange rim. While increasing die corner radius increases thickness and the maximum thinning occurred at the smallest die corner radius. It was found by decreasing the punch profile radius the thickness at the flat bottom of the cup and under the punch profile region were reduced.

Intelligent Speed Controller Design for a Spark Ignition Engine

Saleh Ismael Nejem; Imad Abdul-Kadhem Kheioon

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 99-108

An intelligent and anticipatory speed controller for internal combustion engines was designed theoretically and examined experimentally. This design was based on the addition of a torque loop to the main speed loop. The model can sense the external load with the help of a load cell and send this signal to a soft computing unit for analysis and processing. This scheme will improve the ability of anticipation of controller since it treats the factors that affect the speed, not the speed itself. The experimental design was implemented using two types of actuating techniques; an intelligent throttling actuator and an intelligent injection actuator. The signal was analyzed by using intelligent techniques such as fuzzy logic, neural network and genetic algorithm. The experimental data were used to train the neural and the Adaptive Neuro–Fuzzy Inference System. The comparison of the results obtained in this work with other available models proved the efficiency and the robustness of the present model.

Modeling and Computational Analysis of Turbulent Free convection in Tall Enclosure Filled with Nano-Fluid

Karima E. Amori; Qasim Kadhim Hunehen

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 109-121

In this work, the turbulent buoyancy driven fluid flow and heat transfer in a differentially heated tall rectangular enclosure filled with nanofluid is quantified numerically. The two dimensional governing differential equations (continuity, momentum, energy and low Reynolds number LRN k-ω turbulence equations) are discretized using the finite volume method. SIMPLE algorithm is employed to obtain stabilized solution for high Rayleigh numbers. Two types of nanofluids namely, Al2O3-water and Cu-water, were considered. The effect of Rayleigh number (1010 to 1012), diameter of nanoparticles in the range 25-100 nm, nanoparticle volume fraction in range 0-0.08 and the aspect ratio (30, 40 and 50) on fluid flow and heat transfer are investigated. The present results are compared with previously published work and a qualitative agreement with good validation is obtained. Results show that addition of nanoparticles makes the liquid be more viscous which decreases the vertical velocity component and also decreases the temperature gradient near the walls. Also an announced heat transfer enhancement is obtained with nanoparticle volume fraction reaching a maximum point called optimal volume loading, at which the maximum convective heat transfer is obtained, and then it decreased with further increase of volume fraction.
Keywords: Natural convection; turbulent; tall enclosure; finite volume method; nanofluid.

Numerical and Experimental Study of the Performance of Electromagnetic Flowmeter in Annular Flow

Ihsaan Nadhum Jawaad; Muneer A. Ismael

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 122-136

The present numerical and experimental work investigates the performance of electromagnetic flowmeter (EMF) for measuring the flow rate of annular flow. Adaptive finite difference technique is used for the numerical calculations and the experimental work is done by making some modification on an existing electromagnetic flowmeter and its testing rig. The performance of the modified EMF is evaluated using two criteria namely, the flowmeter sensitivity S and the conventional weight function non uniformity ε. These two criteria were checked against two parameters; thickness of flowing water (δ) and the electrodes angular position (θe). Experimentally, three different water thickness (δ/Ro = 0.216, 0.373, 0.218) and three electrode position (θe=0o, 11.25o, 45o) were studied. The theoretical and experimental results have showed that these devices work properly in the annular flow case, where the most suitable electrode position in the annular flow was found to be in the conventional position (θe =0o).

Natural Convection Heat Transfer in Arc Shape Wall Porous Cavity Filled with Nano-Fluid

Muneer A. Ismael; Huda A. AL-Mayahi; Ihsan N. Jawad

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 137-148

Natural convection heat transfer in porous cavity with arc shape wall filled with nanofluid is studied numerically. The right arc shape wall of the cavity is heated at constant temperature (Th) while the left wall is kept cold at constant temperature (Tc), and the other horizontal walls are thermally insulated. The governing equations of the heat transfer and nanofluid flow are solved Flex PDE software. A temperature independent nanofluids properties models are adopted. The investigated parameters are the nanoparticles volume fraction Ø= (0-0.2), Rayleigh number Ra (10-1000) and arc center Ce (1-∞). The results are presented by contour of streamlines, isotherms and the average Nusselt number. The results have showed that the average Nusselt number decreases with increasing Ce and increases with increasing Ra and Ø.

Optimum Refrigerant Charge of Refrigerator Working with Alternative Refrigerants for R12 (R134a, R600a and R290)

Ali Khalid Shaker Al-Sayyab

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 149-154

This study presents the impacts of suitable refrigerant charge to test the performance of laboratory refrigerator rig for using three refrigerants of (R134a, R600a and R290) instead of R12 .The coefficient of performance and maximum consumption amperes are taken as function to evaluate the optimum charge of these refrigerants. The results imply that the over refrigerant charge will reduce the system performance. Compared the optimum refrigerant charge of R600a is (45g), R290 is (70 g) and R134a is (60g), instead of R12. The results show that the refrigerator with R134a gives lowest capacity reduction with same performance to R12 from other alternative refrigerant, and can be taken as the best alternative refrigerant.

Production of Al-Mg alloy Ribbons by Using Single Roller Wheel Melt Spinning as a Non-Conventional Forming Technology.

Ahmad. K. Jassim; Ali S. Hammood

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 155-161

Single roll melt spinning is a non-conventional forming process used to produce rapidly solidified thin ribbons as a near net shaper by direct casting from liquid state. In this paper, single roll made from brass with a diameter of 150 mm was used to produce rapidly solidified Al-Mg alloys ribbons. The ribbons are produced with thickness in the range of 20 to 330 μm. The results exhibited unique advantages in refining the microstructure, and modifying the mechanical properties of these ribbons. The hardness was improved to about twice the original hardness of alloy. Moreover, corrosion resistance of alloy was improved and their rate was redcued from 10.02 to 1.643 mpy for alloy type 5052 and from 6.91 to 1.943 mpy for 5083.


Mujtaba Almudhaffar; Ali A. Monem; Ahmed H. Naseer

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 162-175

The present work is aimed to reduce the annual electric energy consumption in a residential building in Basrah city through introducing a standardized rule for the annual electrical consumption for the cooling and heating purposes.
This work will concentrate on all parameters which help to go toward the optimum use of thermally efficient house. The building energy analysis program e-Quest was used to simulate the annual energy consumption for a typical residential house built with different types of building materials. Transfer function cooling load calculation was used.
The results showed that for the Base- House, the thermal transmission through the walls and roof constitutes more than half of the total peak cooling load. It was found that a house built with thermo-stone causes 5.9% reduction of the annual cooling energy consumption, and 12.4% in the annual heating energy consumption. However, insulating the Base- House causes a significant reduction in the air conditioning equipment capacity and consequently reduction in cooling energy consumption by 23%, and reduces the heating energy consumption by 42.8%. Finally this work presents a useful planning to developed building design which reduces the electrical energy consumption

Tensile and Buckling Analysis of Polymeric Composite Columns

Jawad Kadhim Oleiwi; Emad Saadi Al- hassani; Alaa Abd Mohammed

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 176-188

This research studied the critical load of composite columns theoretical and numerical by using ANSYS14 package depended on experimental tensile properties of composite specimens. The composite specimens were prepared by hand lay-up technique made from unsaturated polyester reinforced with glass fibers with different fiber volume fraction Vf, aspect ratio (L/T), and angle of fibers for coarse and fine woven fibers.
The critical load that obtained by using program (ANSYS 14) have also shown a good agreement with results that were obtained theoretically and the maximum difference was (0.7%).
The results show that the maximum value of the critical load can be observed at Vf =11%, L/T = (3.5) and θ = (0º/90º) for fine woven fibers was (622.115N). Also its found the maximum critical load for coarse woven fibers can be observed at Vf %=8%, L/T=(3.5) and θ = (0º/90º) was (486.887N). Also the observed values of tensile properties and predicated values are scattered close to the (45˚) line.

The Parameters Change with Different Operation Conditions of Solar Chimney Power Plant Model

Rafid M. Hannun; Salih E.Najim; Mohammed H. Khalaf

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 189-199

The solar chimney power plant is one of the modern models studied on the world. This study presents an engineering and numerical analysis of solar chimney with different parameters. Also, it studies the comparison of two collector base shapes(circular and hexagonal) depend on the five storage material types and their effects on the heat transfer, velocity, efficiency, etc. inside the solar chimney system by considering the solar array intensity equations and the energy equation to calculate the heat transferred and stored by applying the laws of CFD. The finite volume method is used to analyze the geometry physical model by applying a commercial Fluent 6.3 code with Gambit 2.3. The obtained results show that the efficiency of solar chimney is increased by increasing the area of solar glassed collector with circular base shape than the others of polygonal or rectangular one because the circular was covered large area of system. So, the circular ground collector shape for thermal storage is the favour because it is the better to increase the velocity of entering air and to increase the efficiency of turbine. In addition to that the black Pebble storage plate is the better material for heat storage which is convected to air passed for operation of turbine than the other types aluminum, tar, copper and steel seriously.
Keywords: solar energy, power tower, power chimney, renewable.

Theoretical and Experimental Study of the Intake Manifold Effect on the SI Engine Performance

Qais A. Rishack; Sadoun F. Dakhil; Mohammed K. Obaid

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 200-215

This work uses different shapes of intake manifold for study the effect on a single cylinder four stroke gasoline engine. A numerical simulation of the flow achieved through five intake manifold designs, using 3D Computational Fluid Dynamic (CFD) software package FLUINT (6.3.). Accordingly, the three-dimensional resolution of Navier-Stokes equations in conjunction with the standard k-ε turbulence model is undertaken to provide knowledge of the air movement nature and examining the intake manifold optimal geometry. Five cases of intake manifold are examined experimentally in order to produce a comprehensive and realistic data set. These data are in the form of engine performance, exhaust gas products and relative AFR for each case separately under different engine speeds. Exhaust gas analyzer type (Infragas-209) is used in the present work to measure exhaust gas concentrations and relative air/fuel ratio ( ). The results were obtained in this investigation showed that a Simulate numerically and experimentally is capable to select the optimized intake system geometry with reliability. Velocity is highest near the outer wall at increased the curvature ratio and pressure is highest near the inner wall at increased the curvature ratio. The secondary flow increases when the engine speeds and curvature ratio increase because of increasing the pressure difference between the inner wall and the outer wall. The effect of these parameters explained on the swirl air movement and tumble inside the cylinder are increasing by increase the engine speed and γ respectively. The increasing in the engine speed and the optimum selection of the manifold which designed enhanced the mixing of the fuel with air. The results showed that the optimized manifold 135º- NE (case 5) due to enhance AFR, fuel consumption and exhaust emissions are improved.

Transient Buoyancy- Driven Laminar Convection in an Inclined Three- Dimensional Trapezoidal Enclosure

Ahmed Kadhim Hussein; Kolsi Lioua; Hussain H. Al-Kayiem

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 216-228

Numerical analysis of transient laminar threedimensional
buoyancy-driven convection in an inclined threedimensional
trapezoidal air-filled enclosure was investigated in
this paper. The right and left sidewalls of the enclosure are
kept at constant cold temperatures. The bottom wall is
maintained at a constant hot temperature , while the top wall is
considered adiabatic. Numerical investigation is performed for
Rayleigh numbers varied as 103 ≤ Ra ≤ 105 , while the
trapezoidal enclosure inclination angle is varied as 0° ≤  ≤
180°. Prandtl number is considered constant at Pr = 0.71. Flow
and thermal fields are presented in both two and threedimensional
pattern. Also, both local and average Nusselt
numbers are calculated and discussed. The results show that
when the Rayleigh number increases, the flow patterns are
changed especially in three-dimensional results and the flow
circulation increases. The minimum average Nusselt number
inside the trapezoidal cavity corresponds to the highest
inclination angle [i.e., 180 ].While, the average Nusselt
number reaches its maximum value at    30 . Moreover,
when the Rayleigh number increases the average Nusselt
number increases as expected.


MUJTABA ALMUDHAFFAR; Ameen A. Nassar; Hani A. H. A . Kareem

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 229-239

The frequency analysis of bones is a new tool to assess bone quality or integrity to characterize osteoporosis. The modal analysis can also be used to determine failure characteristics of remodeled bone in the fractured model.
This study describes the numerical characterization of the modal analysis of the standardized femur model. The objective of the numerical procedure is to identify the natural frequencies and mode shapes of an unconstrained femur.
The vibration modes of the human femur are studied by digital modal analysis and finite element simulation using ANSYS version 10 programs, with respect to femur dimensions and mechanical properties.
The changing of the values of free vibration natural frequencies and mode shapes of the femur due to changing of the femur densities are studied.
The results are compared to those obtained experimentally. The comparison of the results shows a good agreement, which indicates that the used model can be utilized in vibration analysis of bones.

Numerical Investigation of the Effect of Wire Screen Mesh Specification and Evaporator Length on Thermal Performance of Cylindrical Heat Pipe

Hassanain Ghani Hameed; Abudl-Muhsin A. Rageb

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 240-254

A numerical model has been developed to determine the effect of the wire screen mesh (wick) type on the heat transfer performance of copper–water wicked heat pipe. This model represented as steady-state incompressible flow. The governing equations in cylindrical coordinates have been solved in vapor region, wick structure and wall region, using finite difference with forward-backward upwind scheme. The results show that increasing the mesh number led to decreasing the maximum heat transfer limit and increasing the capillary pressure. While, for the same heat input the operating temperature of the heat pipe increase when the mesh number increase. Also, it was found that increasing the evaporation length, with constant condensation length, decrease the operating temperature and increase the maximum heat transfer limit. For verification of the current model, the results of liquid pressure drop for a heat pipe have been compared with the previous study for the same problem and a good agreement has been achieved.

Graphical User Interface (GUI) for Torsional Vibration Analysis of Rotor Systems Using Holzer and MatLab Techniques

Ameen Ahmed Nassar

Basrah Journal for Engineering Science, Volume 14, Issue 2, Pages 255-263

In this study, a new approach for the torsional vibration analysis of rotor systems using Holzer and Matlab techniques, by developing a graphical user interface (GUI), has been introduced. The objective of the work is to show the usefulness and power of Matlab GUI in investigating and analyzing the effects of torsional vibration on rotor systems. Also to carry out an analysis using the developed GUI to simulate three different rotor configurations such as 2-Rotor, 3-Rotor, and 5-Rotor systems. Illustrated problems in the field of analysis of torsional vibration are carried out. The results show that the developed GUI is very useful for engineers, designers, and analysts of torsional vibration problems in rotor systems.