Investigation about Electrorheological Squeeze FilmDamper Applied to Active Control of Rotor Dynamic

摘要

Electrorheological (ER) fluids, discovered in 1947 by W. WINSLOW, are concentrated suspensionsof solid particles in an oily base liquid. Exposed to a strong electric field, theirresistance to flow increases very greatly and this change is progressive, reversible and occursvery rapidly. Nowadays, ER fluids, made of lithium salt and fluorosilicon got rid of their oldabrasive characteristics and are able to provide a good interface between electronics andmechanical components. A bibliographical study on ER fluids and ER technology has beencarried out. The aim of this study is adapting ER technology to Squeeze Film Damper. Inorder to provide an active control on a flexible rotating shaft so as to command the wholeshaft/bearings device in case of high rotating speed or heavy load trouble. Results of numericalcomputation of a shaft bearing assembly with a Squeeze Film Damper using negativeER fluid are showed in order to see the possibility of avoiding critical speeds by naturalfrequency shifting. A technical study of ER Squeeze Film Damper design is also presented,taking into account ER fluid properties and ER technology requirements.