The importance of journal bearings' analysis due to their abundant use in the industry is obvious to all. Reynolds equation which is used in most of the journal bearing analysis is derived using various simplified mass and momentum equations. There are a lot of analytical and numerical methods for the analysis of journal bearings using Reynolds equation. Analytical methods are often combined with some simplifications for certain cases, which are associated with significant error. In addition, these methods are not capable for analyzing complex bearing geometries. Finite difference methods has less error compared to analytical methods and are capable of analyzing a wide range of bearing length to diameter ratio. These methods, however, are incapable of analyzing complex bearing geometries. The purpose of this thesis is to provide a comprehensive approach in the analysis of journal bearings. To analyze the flow in a journal bearing, the conservation equations of mass, momentum, and energy are solved by the use of dynamic mesh method in CFD. In addition to less value of error compare to two other methods, proposed method is able to analyze any complex geometry of the journal bearing. To verify the accuracy of this method, at first the infinitely long and infinitely short approximation journal bearings are analytically and numerically analyzed for different loads and the predicted values for eccentricity ratio and maximum pressure by means of these two methods have been compared. The obtained results are fairly close especially at the lighter loads. It should be note that there is no analytical solution for the finite length to diameter ratio journal bearing. Therefore, a method based on the analytical solutions of approximately short and long journal bearings is presented in order to analyze the finite length to diameter ratio of journal bearing. In addition analysis is done for these lengths to diameter ratio using the above methods and the eccentricity results obtained from both solutions are compared. In this case the error value is less than the other two. After ensuring the accuracy of network-based computational fluid dynamics, motion bearings with complex geometry were simulated. For this purpose, the bearing of a turbocharger is considered. Initially, the deviation of rotational speed of journal’s effect on the eccentricity ratio, attitude angle, friction torque, the rate of maximum temperature rise caused by friction loss and the increases in the oil temperature from the inlet to outlet were studied. The results show increase in attitude angle, temperature, friction torque and decrease in eccentricity ratio with the rise in rotational speed of journal. Finally, to demonstrate the effectiveness of the method, turbocharger’s bearing with four axial grooves are simulated and the results are compared to those without grooves. According to the results obtained by adding the grooves to Turbocharger’s bearing, the eccentricity ratio of bearing and lubricant flow rate were increased and the attitude angle, the rate of temperature rise and the friction torque are decreased. Key words Journal Bearing, Turbocharger’s bearing, Analytical Solution, Dynamic Mesh, Axial groove