Research On Dynamic Characteristics Of Floating Ring Squeeze Film Damper

The squeeze film damper is widely used in turbomachinery, because it effectively reduced vibrational amplitude and transiting force through the supports under the critical speeds. Dynamic characteristics were studied for dual rotor supported on floating-ring squeeze film dampers(FSFD) in this paper. The main harvests and conclusions were researched as following:(1) Under the condition of considering the deformation of a floating ring, Reynolds equations of inner and outer film of FSFD were derived basing on the fluid motion equations and mass conservation equation. Dynamic model of FSFD were established according to the balance between the inner and outer film pressure as well as the deformation coordination relationship of a floating ring, and provided better theoretical foundation for FSFD dynamic characteristics analysis.(2)The calculation program was written basing on finite difference method and according to the model in the paper. The characteristic influences were studied for FSFD about the structural and film parameters. The results showed that nonlinear characteristics were obviously improved and reducing vibration characteristics was better for the FSFD comparing with the traditional SFD. Under the same conditions, the film force acting on the inner was larger than the outer. The film force on the inner and outer increased as their width, decreased as their clearance and hole diameter on the floating ring increased.(3) The dynamic characteristics of FSFD were validated making use of two orthogonally directions exciting test rig. The influences on the film pressure were studied about exciting force amplitude, frequency, oil clearance and width of film. The experimental results identified well to theoretical analysis. The correctness of the model was proved in the paper and it possessed a good directing significance for engineering application.(4) A dynamic model is established for a dual rotor supported on ball bearings with FSFD, and the influences were analyzed for FSFD on the dual rotor system. The results showed that the performance of FSFD was better than traditional SFD for to reduce vibration through the critical speed under the same conditions of the structure parameters.The researched results provided an important guiding role in designing more reliably, more reasonable FSFD, expected to apply in the actual engine for reducing vibration.