الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
The textured surface has a large number of parameters. The influence of these parameters on the journal bearing performance under thermo-hydrodynamic conditions is the object of the present Ph.D. thesis. The strategy of this research plan is to investigate the effect of each parameter individually by varying its value while the remaining parameters having a fixed value. The work plan strategy has two separate categories. The first category is the shape of dimples, in which the present research aims to study the effect of shape parameters. The parameter optimization is to determine the preference for the dimples to be convex or concave, for the same base area which is better to select elliptical, triangle or square curvature shape. Furthermore, the direction of curvature preferred to be parallel or perpendicular to the sliding direction. Finally, specify the difference between the elected plurality dimples over the bearing surface or the longitudinal or circumferential channels. The second category is opposite to the first one, since the shape of the dimples (concave half-elliptical) does not vary. This part of work proposes to investigate the optimum position, number, and maximum height of the dimples. For the exploratory study and analysis done in this thesis, the finite difference method was adapted to solve the energy equation, the heat conduction equations, and the Reynolds equation numerically. The lubricant film thickness is divided to a mesh of 720,000 nodes, 400 elements in the circumferential axis, 200 nodes in the longitudinal axis, and 9 nodes in the radial axis. A MATLAB code was established to solve the equations for each node of the mesh. For texture shape optimization, 24 cases of different texture shapes were selected (first category), whereas for the second category, five cases of different texture positions were elected. Plurality cases of dimples number and maximum height of dimples were studied to investigate the optimization of these parameters. The present Ph.D. thesis provides theoretical insights about the effect of texture shape and other parameters on journal bearing performance under thermo-hydrodynamic conditions. It was concluded that in order to get high load-carrying capacity, the direction of curvature is preferably to be perpendicular to the sliding direction. The convex texture has a higher load-carrying capacity than concave texture. Finally, for the first category, the surface with textures in channel form yields better overall performance than the surface with several dimples. The results from the second category concluded that the presence of dimples at the high-pressure region is useful to enhance journal bearing performance. Increasing the number of dimples increases load-carrying capacity (LCC). Furthermore, increasing the number of dimples in the longitudinal direction has a larger influence than the number of dimples in the circumferential direction. Finally, as the maximum height of dimples increases, the journal bearing yields high LCC and low friction force FF.