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تحلیل ارتعاشات روتور دارای اثر غیرخطی هندسی با یاتاقان پد متحرک (تیلتینگ پد) | ||
| نشریه مهندسی مکانیک امیرکبیر | ||
| مقاله 10، دوره 52، شماره 1، فروردین 1399، صفحه 141-154 اصل مقاله (948.12 K) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/mej.2018.14537.5878 | ||
| نویسندگان | ||
| سید علی اصغر حسینی* 1؛ امین تمدن2؛ مهدی زمانیان3 | ||
| 1دانشگاه خوارزمی*فنی | ||
| 2گروه مهندسی مکانیک، دانشگاه خوارزمی | ||
| 3دانشگاه خوارزمی تهران | ||
| چکیده | ||
| در این مقاله، ارتعاشات روتور پیوسته با مقطع دایروی یکنواخت که بر روی دو یاتاقان پد متحرک )تیلتینگ پد( قرار دارد مطالعه می شود. روتور الغر فرض میشود و در نتیجه، اثر تغییر شکل برشی نادیده گرفته شده است ولی اثر ژیروسکوپی لحاظ می شود )تئوری تیر ریلی(. به عالوه اثر غیرخطی هندسی ناشی از تغییر شکل بزرگ روتور در نظر گرفته می شود. بر اساس فرضیه یاتاقان کوتاه، یک مدل تحلیلی غیرخطی از یاتاقان پد متحرک که با سیال روانکاری شده و دارای جریان آرام و مغشوش می باشد مدل سازی شده است. معادالت حرکت روتور با دو یاتاقان پد متحرک که در ابتدا و انتهای آن قرار دارند استخراج می شود. به منظور گسسته سازی این معادله ها از روش گلرکین استفاده می شود. با حل عددی معادله های گسسته حاکم بر مسئله، منحنی پاسخ فرکانسی سیستم بدست می آید. با مقایسه پاسخها مشخص می شود که سیستم روتور غیرخطی-یاتاقان پد متحرک دارای دامنه کمتری نسبت به روتور خطی با یاتاقان پد متحرک می باشد. همچنین پاسخ سیستم روتور-یاتاقان پد متحرک با جریان مغشوش باعث سفتتر شدن یاتاقان و کاهش دامنه پاسخ سیستم می شود. با کاهش لزجت دینامیکی سیال، از سفتی یاتاقان کاسته م یشود و سبب افزایش دامنه پاسخ م یشود. | ||
| کلیدواژهها | ||
| ارتعاشات غیرخطی؛ روتور پیوسته؛ یاتاقان پد متحرک؛ تئوری تیر ریلی؛ فرض یاتاقان کوتاه | ||
| عنوان مقاله [English] | ||
| Vibrations Analysis of a Rotor Supported by Tilting-Pad Journal Bearings with Considering of Geometric Nonlinearity | ||
| نویسندگان [English] | ||
| Seyed Ali Asghar Hosseini1؛ A. Tamadon2؛ Mahdi Zamanian3 | ||
| 1Kharazmi University | ||
| 2Department of Mechanical Engineering, Kharazmi University | ||
| 3Department of Mechanical Engineering, Faculty of Engineering, Kharazmi University, P.O. Box 15719-14911, Tehran, Iran | ||
| چکیده [English] | ||
| Vibrations of a continuous rotor with uniform circular cross section supported by two tilting-pad journal bearings at both ends are analyzed. Since the shaft is slender, shear deformation is neglected, but, gyroscopic effect is considered (Rayleigh beam theory). In addition, geometric nonlinearity due to large deformation of the rotor is considered. Based on short bearing assumption, an analytical model of a tilting-pad journal bearing with laminar and turbulence flows has been derived. Galerkin method is applied to discretize differential equations of motion. By solving discrete rotorbearing system equations, the response is obtained. For further investigation, responses of rotor-bearing system in different situations are presented. Comparing the responses of the linear and nonlinear rotor with two tilting-pad journal bearings at both ends shows that the nonlinear rotor has less amplitude than linear rotor and nonlinear rotor is closer to reality. In addition, nonlinear model has a larger natural frequency in comparison to the linear rotor. Using turbulence flow makes the bearing stiffer and have less amplitude than laminar flow. Reducing viscosity of lubricant leads to increase of amplitude of response and shows that higher viscosity make the bearing stiffer. | ||
| کلیدواژهها [English] | ||
| Nonlinear vibrations, Continuous rotor, Tilting-pad journal bearing, Rayleigh beam theory, Short bearing assumption | ||
| مراجع | ||
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