Study On Resonance Changer Used To Attenuate The Longitudinal Vibration Of The Shaft-line System In Marine Ship

Resonance changer is implemented within the thrust bearing to support thrust pads.Resonance changer used to attenuate the longitudinal vibration of the shaft-line system canminimize marine ship noise radiation and improve passenger comfort.The vibration attenuation mechanism, the longitudinal static stiffness, the equivalentdynamic parameter identification, the influence of the shaft-line system parameters on vibrationattenuation function of resonance changer are studied in this paper. The main research contentsare listed as follows:1. The summarization of the vibration attenuation mechanism of resonance changer. Thecauses of the longitudinal vibration in marine ship are introduced, and early solutions arediscussed. Through the comparatively analysis of results obtained by the theoretical calculationformula of the equivalent dynamic parameters and measured in marine ship, it is proved that thetheoretical calculation formula can preferably reflect the vibration attenuation mechanism ofresonance changer in the low frequency of the exciting force.2. Using hydrostatic bearing to increase the longitudinal static stiffness of resonancechanger. The static stiffness characteristic is analyzed based on hydrostatic bearing throttlingmodel of resonance changer. The result shows that the increase of the static stiffness can berealized by hydrostatic bearing.3. Study on equivalent dynamic parameter identification of resonance changer based onnumerical simulation. The unsteady flow of the compressibility liquid in resonance changer issimulated by using FLUENT. Then, the identification of its equivalent dynamic parameters isdiscussed which is compared to the result obtained by its theoretical calculation formula.Analysis shows that as the frequency of the exciting force increases, the equivalent dynamicparameters would change obviously, and the theoretical calculation formula of the parametersbecomes improper.4. Influence of shaft-line system parameters on vibration attenuation function of resonancechanger. Computation model of shaft-line system for analyzing transmission of propellerexcitation to ship hull based on the four-pole parameters is established. The result shows that the shaft-line system parameters have small effect on the vibration attenuation function of resonancechanger.