University of Thi-Qar Journal for Engineering Sciences

The big increase of the ambient temperature during the summer season leads to increase of energy consumption for air conditioning which in turn increases peak electrical study load. In this work, theoretical and experimental study are performed for hybrid system combined of evaporative air cooler and refrigeration unit. The experimental rig is build and tested during the summer months. The theoretical model is performed based on heat and mass transfer for the hybrid system. The effect of may parameters are studied such as, water temperature, water and air mass flowrates and wetted pad thickness. The results show that the pre-cooling water temperature improves effectiveness by about (5-10%). The results of the present work are compared with results of other works and show a good agreement.

The determination of fatigue life of mechanical parts such as welded joints during service which subjected to high stresses and cyclic loading is extremely important. In order to investigate life span of mechanical parts a finite element analysis is used. In this paper, an experimental investigation and numerical analysis is used to study the effect of geometrical parameters on fatigue life span. The experimental parts include monotonic tensile test and hardness test of welded joints of steel S355JR laser butt welded joint. A parametric finite element analysis is performed by using ANSYS 11 software to investigate the effect of plate thickness (h) and weld toe radius (r) in butt welded joint on fatigue life. Different values of plate thickness and radius of weld toe have been investigated during this study; the results indicate that increasing the plate thickness and radius of weld toe will improve the stress distribution in the joint and increase the fatigue life span of welded joint.

Study the simulation of human response during the moving on various roads and represent the human body as discrete masses, springs and damper system. Assessment of vibration condition impacts of human in the perspective of the unfavorable safety impact was introduced. Be that as it may, it is important to do the comprehension the impact of vibration to human body to look at their legitimacy and to plan for the future vision. This paper demonstrates the point of interest estimation of human reaction to vibration, and the displaying of the human body for the appraisal of the vibration hazard.The vibration transmissibility from the beginning of the human body amid the introduction to vertical excitation. The modular parameters are resolved with a specific end goal to comprehend the standards normal modes.The model shows that human reaction relying upon vibration condition. The presentation of the present model to vibration stacking is contrasted and the examination information and a practical contract are found. The presentation of human determination demonstrates a geometric depiction of the parameters which influence the unwavering quality of a basic segment subjected to vibration stacking. The control of the investigative model and the recreation examination in the present work demonstrating the distinctive mode shapes, Eigen values/vectors,and the burdens brought about by such vibration stacking that can lead. The model is introduced to manage the human agreeable and to locate a fitting blend between human reaction and vibration condition.

The direct – switched apparatus in use nowadays are connected to the mains through plugs and sockets. These are generally agreed in natural environment, but can be prohibited or have limited life in the presence of moisture, in explosive atmospheres and inside sea applications. So contactless power transmission through a large air-gap is becoming more suitable for the above applications. This paper discusses the effects of geometrical arrangements of contactless transformer for two core types, U-U type and E-E type by means of flux simulation based on finite element method with ANSYS program v 5.4 . It is found that the U-U type core can give higher coupling coefficient within the same core geometry and lower leakages. It could be concluded that the dimensions of the core and the air-gap length determine the transmission behavior.

Recently, the number of accidents in Iraq increases sharply after 2003 as the number of vehicles increases rapidly. The absence of adequate documentation system leads to unclear picture of the cause of these accidents. Therefore, this study tries to put the first step toward recoding the accurate details of the accidents. The GIS technique has been adopted as a knowledge base for the accidents recording along different types of roads within Al-Najaf city as study case. Reference points have been suggested on roads using electrical columns which already were installed along these roads. To link these referencing points together with GIS, there is a need for new accident form. This form will includes, in addition to the types of accidents, the causes of accidents and the name of roads, the referencing point which is close to the accident location. This system has been built according to field data collecting from miscellaneous resources. The developed model is able to indicate the black spot location (i.e. the location with high frequency of accidents) by change the color of points or segments relating to black spot. The developed system now is ready to be used by the authority of traffic.

The collapse of the bridge are due to inadequate seismic performance of bridge pier (or pile) and columns, which provided with poor ductility and energy dissipation. Deep study of strengthening structural element concern elasto –plastic behavior of concrete would be important to increase the capacity of structures elements. Considering the rapid development of economic construction and the Traffic volume through different regions has been escalating, there is a substantial contribution has been developed in traffic construction and structures. This research focus on new strengthening method to provide effective confinement to the concrete core and obtain elastic deformation of the circular columns. The finite element software ABAQUS used for the nonlinear numerical analysis of the concrete column strengthening with polyurethane cement composite mix. Results shows that the use of new technique for strengthening has greatly improved the ultimate capacity of column. The thickness of strengthening material is the main parameters in this study and govern by the behavior of polyurethane-cement material. The improvement ratio in loading capacity with confinement thickness 40 mm and density of confinement material 1600 Kg/m3 is 277% compared with non-strengthening model.

In this study a theoretical model was accredited to show the effect of dissociation phenomenon on adiabatic flame temperature. CH4, C2H6, C3H8 and C4H10 as gases fuel, global reaction and a thermodynamics analysis were dependent in this model to analysis a combustion to evaluated adiabatic flame temperature. Four cases are studied no dissociation, only H2O dissociation, only CO2 dissociation and both H2O and CO2 dissociation together. The results show that with dissociation adiabatic flame temperature will be decreased and the bigger effect on adiabatic flame temperature when only CO2 dissociation. Also the effect range of equivalence ratio on dissociation phenomenon was from 0.9 to 1.1

In the last decades of the twentieth century and the first decade of this century, the issue of rationing energy and the issue of environmental conservation has become the main concern of the company's manufacturing the means of transportation. This can be achieved using Al-alloys and other light alloys as a best alternative for steel in the bodies of the auto industry. Aluminum and light metals alloys have lower melting point and so fusion welding and resistance spot welding processes cause more changes in the properties of these alloys and lead to getting unsound welding. Solid state welding methods such as friction stir spot welding consider the best alternative. In the present work, effect of dwell time and tool rotational speed on microstructural and mechanical properties of friction spot welded joints of AA3105 alloy, was investigated experimentally. The travel speed and plunging depth were kept as constant, whereas, the dwell time and rotational speed parameters were varied with different values and their effect was investigated. Lap shear test, microhardness, and metallographic tests were performed. The results showed that, the shear strength is significantly affected with variation of the input parameters. The main findings of the present work were that high shear strength of the friction stir spot welded joints is achieved at dwell time of 7.5 s and rotational speed of 1400 rpm, as well as the highest microhardness was also achieved with this set of input parameters.

Automatic voltage regulator is used to fix the output signal by correcting the voltage of the exciter and track the generator’s voltage. The improvement of automatic voltage regulator (AVR) response will reflected on the power system performance. In this paper two intelligent techniques fuzzy logic (FL) and Particle swarm optimization (PSO) are used to enhance the response of the Fourth order AVR system based on the merging between them and then the control action summed and coupled with PID controller action. Fuzzy controller has many benefits in design of AVR compared with conventional controllers, but the response of the AVR system still insufficient, therefore, the PSO and Fuzzy are used together for this purpose to produce Fuzzy-Swarm-PID controller (FSPID). Usually the cognitive (C1) and social acceleration (C2) are taken as a constant values in PSO algorithm, but here the Fuzzy logic system is used to get these accelerations to enhance the response.

To reduce the cost and the system complexity in power applications, voltage source five leg space vector pulse width modulation inverter (FLI) is designed to drive dual induction motors. This paper presents independent control of dual induction motor fed by five leg inverter. Indirect field oriented control is used separate by each motor. Two space vector pulse width modulator is utilized to generate the switching signal for FLI and a double zero sequence modulation technique (DZS) is employed to generate the modulation signals. Two motors operate under different operation condition where the result proven that dual induction motor can independently controlled by FLI.

Cooling tower is vastly utilized in industries as well as plants such electrical energy generation field and petrochemical industry to subtract the useless heat . In this paper, a thermal behavior of mechanical draft cross flow wet cooling tower is investigated .The theoretical study based on mathematical model of heat and mass transfer whose analyzed by ANSYS fluent software code employed workbench. Three new configurations of cooling tower are studied at the first time that didn’t studied together in literatures. They are cubic, cylindrical, and pyramid shape. The investigation used several inlet water temperature and different pressures of water at inlet and outlet. The numerical solution is based on the finite volume method. The wet bulb temperature of air has constant value for all cases whose studied . The results of study indicated that the cylindrical configuration is the best geometry. When inlet water pressure get up at constant other variables, the performance is decreased as well as it will improved if it reduces. The water cooling range has no influence on the tower characteristics.

Erosion corrosion process is considered one of the main problems to which too ls, machine parts and equipment are subjected and which operate in fluidized media. Solid particles strike them because of fluid motion at different speeds and varying time periods. Erosion corrosion system was made according to ASTM Specification. Circular test samples were made in diameter 15 mm and length of 50 mm from Al alloy 6061-T6 and Free Cut Brass 360 and polymer. Erosion corrosion test was made using weight loss method in sea water and Tigris river water at 500, 400 and 300 rpm for 1, 2, 3, 4.5.6 hrs. From the results reached, it is found that with increase in time, the erosion corrosion rate increases for both mediums because of the effect of medium components such as chlorine and oxygen for a certain period. When the time period increases, it decreases because the oxygen dissolved in water is used up which is responsible for corrosion. Also a protective is formed from the remnants of corrosion process. Moreover, it is found when speed increases, corrosion rate decreases due to speed prevent ion from summing at electrods.

Four different quenching media (water, oil(SAE 10W40), Water/TiO2 nanofluid and oil(SAE 10W40/TiO2) nanofluid were used to compare the influence of quenching media on the mechanical properties and microstructure of CK35 steel. The results have proved that the microstructure for nanofluid (water base) quenching and tempering sample is the combination of tempered martensite and retained austenite with best mechanical properties and for water quenching and tempering specimen is mostly tempered martensite. While for Nanofluid (oil base) quenching and tempering specimen the microstructure is the heterogeneous mixture of ferrite and perlite with formation of Fe3C during the quenching, while for oil quenching and tempering specimen is an equi-axed arrangement of ferrite grains with grainy spheroidized spots of cementite at the ferrite grains and along the grain boundaries.

the save of soldier’s life in battlefield is an important thing in any battle plan. One of the solutions to economize the numbers of losses of soldiers’ life’s, is to use unmanned autonomous cart to perform some deadly functions in place of soldiers. This research proposes unmanned armed cart to support Iraqi army operations and to protect the soldiers from the snipers deadly shooting and from the explosion of mines. The proposed cart is armored and moving on four wheels. It is armed with machine gun and supplied with camera. All the commands of operations were performed using Programmable Logic Controller "PLC". The experimental performance passed successfully by the use of remote control.