Cover

Aims and Scope
Editorial Board

1. Effect of using diesel - water emulsion as a fuel on diesel engine emissions: An experimental study

Abdulrahman Shakir Mahmood¹, Haqi I. Qatta², Nassr Fadhil Hussein³, Ali A. Ismaeel³

1 Environmental Research Center, University of Technology, Baghdad, Iraq.

2 Nanotechnology and Advanced Materials Research Center, University of Technology, Baghdad, Iraq.

3 Department of Electromechanical Engineering, University of Technology, Baghdad, Iraq.

Abstract: Diesel engines are considered one of the main sources of air pollution because of the gases emissions and particulate matter (PM), so, must be searched for a fuel helps to reduction from these harmful emissions. The aim of this research is to study the effect of using diesel-water emulsion as a fuel on diesel engine emissions. In this study, an experimental test was conducted on a single cylinder four-stroke diesel engine at constant speed (1500 rpm) and various loads (0% to 100% load) fueled with different ratios of diesel-water emulsions and compared it with the pure diesel fuel. Emulsion was prepared with proportions at 5%, 10%, 15% and 20% of the volume of water in diesel fuel; the Tween 20 and Oleic Acid were used as a surfactant to maintain the stability of emulsion fuel for long periods of time. The tests were conducted on the engine and NOX, HC, CO, and CO₂ emissions were measured by using an exhaust gas analyzer of type (AVL DIGAS 444), and smoke opacity by using a smoke meter device of type (AVL 437C). Experimental results showed that the using of diesel-water emulsion significantly reduces from the NOX and smoke emissions. From the results, it was found that the highest of reduction ratio in NOX and smoke emissions were at fuel of WD-20, where they decreased by 32.3% and 38.8% respectively, compared with pure diesel fuel.

2. Active vibration control analysis of pipes conveying fluid rested on different supports using state-space method

Dhurgham Salah Hussein, Muhannad Al-Waily

Department of Mechanical Engineering, Faculty of Engineering, University of Kufa, Iraq.

Abstract: The problem of vibrations cause the collapse of the systems ‎and cause significant economic losses if not avoided. For this reason, the researchers have ‎dealt with this issue in all years, but the problem is not over. In this paper will highlight the problem of ‎controlling the vibrations resulting from fluid flow inside the pipes, in addition to the study of reducing ‎the vibrations of these pipes. ‎The ideal control is designed based on, the state space theory and according to the linear behaviour of time, because the stability of the pipes are found from linear change. Different factors were studied on the controller's performance and then the optimal factors were obtained to obtain the best performance. The research included the study of the response and the natural frequency and the study of the dynamic behaviour of different types of stabilization of the pipes in the presence with no hydraulic damping (active control) and monitoring the response and stability of each case of stabilization. Where, the control investigation include using the analytical solution of general equation of motion for pipe by using state space technique. There, the parameters studied for active control pipe vibration included the effect of hydraulic damper position, base width of hydraulic damper, damping, and the flow Pressure, on the pipe vibration response, with various pipe boundary conditions supported.

3. Frequency domain analysis by using the bode diagram method of pipes conveying fluid

Dhurgham Salah Hussein, Muhannad Al-Waily

Department of Mechanical Engineering, Faculty of Engineering, University of Kufa, Iraq.

Abstract: Fluid conveying pipes are used in all hydraulic systems and enter in all industrial fields, such as water, petroleum products and gases of all kinds. In spite of this widespread and critical importance of fluid conveying pipes, they suffer from major problems and one of these problems is the problem of vibrations that cause the collapse of the systems completely and cause significant economic losses if not avoided. For this reason, the researchers have dealt with this issue in all years, but the problem is not over. In this paper will highlight the problem of controlling the vibrations resulting from fluid flow inside the pipes. The research included the study of the dynamic behaviour of different types of stabilization of the pipes in the presence with no hydraulic damping (active control) and monitoring the stability of each case of stabilization. This study was carried out by deriving differential equations for pipes and for different types of fixation. Special equations with mode response and natural frequency equations were obtained in addition to the stability study of the pipes in the same manner, by using bode diagram technique. This is done by deriving the differential equation of motion and dealing with it for the purpose of reaching the general equation so that it can be easily converted within the method of state space and analysis of equations and find feedback with the change of inputs and outputs. With the help of MATLAB program where the final equations are programmed and the results are found. The main factors of dynamic and stability behaviour were calculated in addition to the main parameters on the pipe such as fluid velocity, pressure and mass ratios.

4. Calculation of elastic deformation under the influence of high velocity impact on composite plate structures

Ali Munther Jaafar, Muhannad Al-Waily

Department of Mechanical Engineering, Faculty of Engineering, University of Kufa, Iraq.

Abstract: Composite materials are widely used in many civil and military applications because of their excellent mechanical properties. In military applications, composite materials are used to protect vehicles and aircraft and to manufacture shields for their ability to absorb and disperse impact energy. In this paper, used high velocity impact with a bullet (it mass of , diameter  and a semi-circular projectile head) with a specific velocity ranging from , to investigate the elastic deformation for composite plate structure with various composite laminated parameters effect. Where, studied the effect of the impact by using theoretically technique, in addition to, calculating the natural frequency for plates by using analytical and numerical techniques, and then, comparison the results obtained. In the theoretical part, problems were analysed into several categories, the first is the calculation of the elastic deformation in the composite materials samples which depends on several parameters such as the calculation of the natural frequency, the time and force contact, and elastic deformation. An equation for the calculation of elastic deformation was derived based on the classical theory of plates. Also, the natural frequency results calculated analytically by using classical theory of plates with drive the general equation of motion. Then, by using numerical technique calculating also the natural frequency of plates, and then, comparison the results obtained with analytical results obtained. When, the numerical technique include using for finite element technique to calculate the vibration behaviour for plate. Then, the comparison for results given a good agreement for analytical technique used with maximum error did not exceed about (1.23%).

5. Experimental and numerical temperature distribution study for harmonic vibration beam with and without crack effect

Diyaa H. J. Al-Zubaidi¹, Muhannad Al-Waily², Emad Q. Hussein¹, Maher A. R. Sadiq Al-Baghdadi²

1 University of Kerbala, Faculty of Engineering, Mechanical Engineering Department, Iraq.

2 University of Kufa, Faculty of Engineering, Mechanical Engineering Department, Iraq.

Abstract: In this study, investigation the temperature distribution of vibration beam under force harmonic load applied with force frequency equal to ( from beam natural frequency). Where, the investigation included study the effect of crack depth and position on the temperature distribution in the beam. There, the beam investigating made of carbon steel materials and supported with various boundary condition. In addition, the investigation included using experimental and numerical technique to calculate the temperature of beam with crack and uncrack effect, with various depth and position crack influence. Therefore, the experimental technique included building of rig vibration and applying to harmonic load on the beam, supported with various boundary condition, and then, measurement the temperature in the beam by using thermal camera. Also, the numerical technique included calculated same variable evaluated by experimental technique with same parameters effect, by using finite element method with using of COMSOL program, and then, calculate the change in the temperatures that appeared in the numerical solution and compare them with the change in the calculated temperatures in experimental work. Therefore, the comparison of results shown that the experimental and numerical results are agreement with maximum error about (10.8%). Where, the results shown that the temperature change with crack beam more than the temperature change of beam without crack, for various beam boundary conditions supported. In addition, the results shown that the time required to stability the change of temperature, due to applied harmonic load, increase for beam with crack effect.