Al-Khwarizmi Engineering Journal

Metal cutting processes still represent the largest class of manufacturing operations. Turning is the most commonly employed material removal process. This research focuses on analysis of the thermal field of the oblique machining process. Finite element method (FEM) software DEFORM 3D V10.2 was used together with experimental work carried out using infrared image equipment, which include both hardware and software simulations. The thermal experiments are conducted with AA6063-T6, using different tool obliquity, cutting speeds and feed rates. The results show that the temperature relatively decreased when tool obliquity increases at different cutting speeds and feed rates, also it is found that the mean tool rake face temperature distribution decreases with increase of tool obliquity. The result also show that the maximum error between the predicted and measured temperatures by IR camera was between 6-27 °C.

Electric arc furnace applications in industry are related to position system of its pole, up and down of pole. The pole should be set the certain gap. These setting are needed to calibrate. It is done manually. In this research will proposed smart hydraulic to make this pole works as intelligent using proportional directional control valve. The output of this research will develop and improve the working of the electric arc furnace. This research requires study and design of the system to achieve the purpose and representation using Automation Studio software (AS), in addition to mathematically analyzed and where they were building a laboratory device similar to the design and conduct experiments to study the system in practice and compared with simulation.Experimental tests show that the performance of electro hydraulic closed loop system (EHCLS) for position control is good and the output results are good and acceptable. The practical results and simulation using (AS) software are clearly convergence. It was concluded that the possibility of the implementation of this project in industrial processes such as electric arc furnaces to control the distance between the pole and smelting molten material in addition to other applications.

In the present work the effect of bearing compliance on the performance of high speed misaligned journal bearing lined with a compliant PTFE liner lubricated with bubbly oil at high speeds has been studied. The effect of induced oil film temperature due to shearing effect has been implemented. Hydrodynamic effect of the complaint bearing and the influence of aerated oil have been examined by the classical thermohydrodynamic lubrication theory modified to include the effect of oil film turbulence and oil film temperature with suitable models for bubbly oil viscosity and density. The effect of liner elastic deformation has been implemented by using Winkler model. The effects of variable density and specific heat on the most importantbearing parameters such as maximum pressure, maximum temperature, bearing load carrying capacity and power losses have been investigated.The results obtained show that the oil film pressure and load carrying capacity increased for the bearing lubricated with bubbly oil of higher aeration level and smaller size of air bubbles. Including the effect of elastic deformation of the bearing liner reduces the oil film pressure, load carrying capacity and frictional power loss for the misaligned bearing working at the same circumstances

This work deals with a numerical investigation to evaluate the utilization of a water pipe buried inside a roof to reduce the heat gain and minimize the transmission of heat energy inside the conditioning space in summer season. The numerical results of this paper showed that the reduction in heat gain and energy saving could be occurred with specific values of parameters, like the number of pipes per square meter, the ratio of pipe diameter to the roof thickness, and the pipe inlet water temperature. Comparing with a normal roof (without pipes), the results indicated a significant reduction in energy heat gain which is about 37.8% when the number of pipes per meter of roof length is 3.0 , the ratio of pipe diameter to the wall thickness (D/W) is 0.20, and the water inlet temperature is 30°C, while the minimum ratio of reduction 24% is achieved when the number of pipes per meter, the ratio of pipe diameter to the wall thickness, and the water inlet temperature are 27, 30 and 33 °C, respectively. The results also showed that there is a very small effect of pipe centre position inside the wall on the final heat transmission.

Machining residual stresses correlate very closely with the cutting parameters and the tool geometries. This research work aims to investigate the effect of cutting speed, feed rate and depth of cut on the surface residual stress of steel AISI 1045 after face milling operation. After each milling test, the residual stress on the surface of the workpiece was measured by using X-ray diffraction technique. Design of Experiment (DOE) software was employed using the response surface methodology (RSM) technique with a central composite rotatable design to build a mathematical model to determine the relationship between the input variables and the response. The results showed that both the feed rate and the cutting speed are the significant factors controlling the surface residual stress, while the depth of cut had no influence. A quadratic empirical model was developed with a 95% confidence level, and a good agreement was found between the experimental and predicted results. A numerical optimization was then conducted through DOE program to find the optimum surface residual stress at the optimum cutting parameters, depending on the maximum desirability obtained. The optimum compressive surface residual stress (-224.361 MPa) was found at cutting speed of 69.2 m/min, feed rate of 0.4 m/min and depth of cut of 0.4 mm.

Friction stir welding is a relatively new joining process, which involves the joining of metals without fusion or filler materials. In this study, the effect of welding parameters on the mechanical properties of aluminum alloys AA2024-T351 joints produced by FSW was investigated.Different ranges of welding parameters, as input factors, such as welding speed (6 - 34 mm/min) and rotational speed (725 - 1235 rpm) were used to obtain their influences on the main responses, in terms of elongation, tensile strength, and maximum bending force. Experimental measurements of main responses were taken and analyzed using DESIGN EXPERT 8 experimental design software which was used to develop the response surface methodology (RSM) models. Mathematical model of responses, as functions of used welding conditions, were obtained and analyzed by ANOVA variance to verify the adequacy of these models. The resultant quadratic models showed that as the rotation speed or welding speed increases, the tensile strength and elongation of the joint firstly increase to a maximum value and then decrease more likely due to the occurrence of void defect. Increasing both welding speed and rotational speed leads to increase the maximum bending force firstly to a maximum value and then decreases. However, the welding speed was found more significant than rotational speed. A good agreement was found between the results of these models and optimization with the experimental ones with confidence level of 95%.

Corrosion-fatigue occurs by the combined actions of cyclic loading and corrosive environment. The effect of shot peening on cumulative corrosion-fatigue life of 1100-H12 Al alloy was investigated. Before fatigue testing, specimens were submerged in 3.5%NaCl solution for 71 days. Constant fatigue tests were performed with and without corrosive environment. Cumulative corrosion-fatigue tests were also carried out in order to determine the fatigue life before and after shot peening. The constant fatigue life was significantly reduced due to corrosive environment and the endurance fatigue limit was reduced by 13% compared with dry fatigue. In case of shot peening the cumulative , corrosion -fatigue life was increased by a factor of about (2) compared with cumulative corrosion-fatigue life without shot peening.It was found that the CFLIF%(Cumulative Fatigue Life Improvement Factor) was about (2-6) due to shot peening surface treatment .

The catalytic cracking conversion of Iraqi vacuum gas oil was studied on large and medium pore size (HY, HX, ZSM-22 and ZSM-11) of zeolite catalysts. These catalysts were prepared locally and used in the present work. The catalytic conversion performed on a continuous fixed-bed laboratory reaction unit. Experiments were performed in the temperature range of 673 to 823K, pressure range of 3 to 15bar, and LHSV range of 0.5-3h-1. The results show that the catalytic conversion of vacuum gas oil increases with increase in reaction temperature and decreases with increase in LHSV. The catalytic activity for the proposed catalysts arranged in the following order:HY>HX>ZSM-11>ZSM-22The product distribution depends greatly on the temperature and on the catalyst type. A higher hydrocarbon yields was obtained for HY zeolite catalyst. The selectivity towards high octane number compounds for the proposed catalysts are arranged in the following order:HY>HX>ZSM-11>ZSM-22The cracking conversion is improved by increasing reaction pressure up to 15 bar. The simulated experiments of the catalytic cracking process show that the higher conversion and more desired products can be achieved to conventional feeds.

The low velocity axial impact of thin-walled circular ck45 tubes is taken. The wrinkles develop progressively and the phenomenon is known as dynamic progressive buckling. In the present paper, experimental and theoretical studies on dynamic plastic buckling of circular cylindrical shells under axial impact are carried out by designing and building a device to study the behavior of ck45 under low speed impact (3.8-6.25)m/s. The work consists of experimental and theoretical (Abramowicz model) for the energy absorbers and dynamic load under different velocities. The results show that when the velocity of impact increases, the value of the dynamic crushing stress for ck45 will increase, also for elastoplastic collapse deformation, a tube initially goes through elastic deformation, then plastic deformation occurs, after that the tube goes through plastic collapse. As the force decreases, the displacement still increases. Abramowicz model for dynamic impact shows well coincide with discrepancy 45%. It can be indicated that the increasing in the velocity or kinetic energy leads to increase in the load in the practical part while it seems to be horizontally linear in the theoretical part.

This paper represents a study of the effect of the soil type, the drilling parameters and the drilling tool properties on the dynamic vibrational behavior of the drilling rig and its assessment in the drilling system. So first, an experimental drilling rig was designed and constructed to embrace the numerical work.The experimental work included implementation of the drill-string in different types of soil with different properties according to the difference in the grains size, at different rotational speeds (RPM), and different weights on bit (WOB) (Thrust force), in a way that allows establishing the charts that correlate the vibration acceleration, the rate of penetration (ROP), and the power consumption curves with the depth of drilling.In addition to that the ANSYS Workbench (the 14.0 release) software was used to simulate and verify the experimental results. And it was also used to model other numerical cases with different drill bit diameters.