تحليل ياتاقان توربو شارژر به كمك روش شبكه بندي متحرك و بررسي تاثير پارامترهاي مختلف بر عملكرد آن

چكيده انگليسي :

112 Analysis of Turbocharger s Bearing Using Dynamic Mesh Method and Study of Different Parameters Effects on its Performance Jafar Moradi Choqamahi j moradi@me iut ac ir Date of Submission 1 13 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Mohsen Saghafian saghafian@cc iut ac ir Mahdi Nili Ahmadabadi m nili@cc iut ac irAbstract 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 simplifiedmass and momentum equations There are a lot of analytical and numerical methods for the analysis ofjournal bearings using Reynolds equation Analytical methods are often combined with some simplificationsfor certain cases which are associated with significant error In addition these methods are not capable foranalyzing complex bearing geometries Finite difference methods has less error compared to analyticalmethods 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 acomprehensive approach in the analysis of journal bearings To analyze the flow in a journal bearing theconservation equations of mass momentum and energy are solved by the use of dynamic mesh method inCFD In addition to less value of error compare to two other methods proposed method is able to analyzeany complex geometry of the journal bearing To verify the accuracy of this method at first the infinitelylong and infinitely short approximation journal bearings are analytically and numerically analyzed fordifferent loads and the predicted values for eccentricity ratio and maximum pressure by means of these twomethods have been compared The obtained results are fairly close especially at the lighter loads It should benote that there is no analytical solution for the finite length to diameter ratio journal bearing Therefore amethod based on the analytical solutions of approximately short and long journal bearings is presented inorder to analyze the finite length to diameter ratio of journal bearing In addition analysis is done for theselengths to diameter ratio using the above methods and the eccentricity results obtained from both solutionsare 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 thispurpose the bearing of a turbocharger is considered Initially the deviation of rotational speed of journal seffect on the eccentricity ratio attitude angle friction torque the rate of maximum temperature rise causedby friction loss and the increases in the oil temperature from the inlet to outlet were studied The results showincrease in attitude angle temperature friction torque and decrease in eccentricity ratio with the rise inrotational speed of journal Finally to demonstrate the effectiveness of the method turbocharger s bearingwith four axial grooves are simulated and the results are compared to those without grooves According to theresults obtained by adding the grooves to Turbocharger s bearing the eccentricity ratio of bearing andlubricant flow rate were increased and the attitude angle the rate of temperature rise and the friction torqueare decreased Key wordsJournal Bearing Turbocharger s bearing Analytical Solution Dynamic Mesh Axialgroove

مرادي چقاماهي، جعفر

تحليل ياتاقان توربو شارژر به كمك روش شبكه بندي متحرك و بررسي تاثير پارامترهاي مختلف بر عملكرد آن

ياتاقان ژورنال , روش تحليلي , ياتاقان با شيار محوري