Simulation And Experimental Study On Dynamic Characteristics Of Squeeze Film Damper

Squeeze Film Damper(SFD)is widely used in aero-engine due to its simple structure and good vibration attenuation effect.However,some of the mechanisms for SFD are still not very clear.In order to enable the SFD to perform a good vibration attenuation effect on the aero-engine,the following research work has been carried out:(1)Using the three-dimensional modeling software UG and computational fluid dynamics software CFD carried out SFD numerical modeling,meshing and oil film pressure field calculation.Under the assumption of SFD short bearing and semi-oil film,the rationality and correctness of the numerical simulation were verified by the formulae of stiffness and damping.(2)In order to reflect the dynamic characteristics of SFD more faithfully,on the one hand,a bidirectional excitation experimenter was used to simulate the working state of SFD,and according to the mechanical impedance principle,the dynamic parameters of SFD were obtained.On the other hand,the CFD software was used to simulate the SFD under the experimental conditions.The results showed that the experimental and numerical results were consistent.(3)The influence of static eccentricity on the dynamic characteristics of SFD was studied by means of CFD.The results show that due to the existence of static eccentricity,the damping and stiffness fluctuate when the journal is in different circumferential positions.When the static eccentricity is too large,a large oil film negative pressure zone is generated,and it is easier to make the oil and gas slide.When the dynamic eccentricity and the static eccentricity are small,the influence of the supply pressure on the damping and the stiffness is obvious;when the dynamic eccentricity and the static eccentricity are large,the influence on the damping and the stiffness is greater than the supply pressure.(4)The effect of oil supply conditions on the dynamic characteristics of SFD was studied by means of CFD.The results show that the oil film damping and stiffness exhibited similar changes to the simple harmonic function for single-hole oil-supply SFD at different circumferential positions of the journal.Multiple symmetry oil supply holes significantly suppress this effect.(5)The dynamic characteristics of the new SFD were studied by means of CFD.The results show that with the same eccentricity,the damper's oil film damping is larger than the traditional SFD,while the oil film stiffness is smaller.