涡轮增压器动力学建模及振动特性研究

Dynamic modeling for a turbocharger and its vibration characteristics

采用结合有限元法(FEM)的多体动力学方法,对某车用浮环轴承涡轮增压器进行多体系统仿真模型的建立:以模态综合法为基础,建立增压器壳体与转子的柔性体子结构模型;以广义不可压缩雷诺方程为基础,建立增压器浮环轴承的EHD弹性液力润滑模型(Elastic Hydro-Dynamic)。计算得到内外油膜压力、转子振动特性以及增压器壳体表面振动速度,并进行实验验证。结果表明,采用柔性体多体动力学与EHD轴承润滑模型相结合的建模方法能够有效用于增压器的振动特性分析,该方法的应用也为研究增压器同步、次同步振动与噪声问题提供了理论依据。

Using the multi-body dynamics theory and FEM,a multi-body system simulation model was established for a certain vehicle’s turbocharger with floating ring bearing.Based on the modal synthesis method,flexible body sub-structure models for turbocharger housing and rotor were built.Based on the generalized incompressible Reynolds equation,an elastic hydro-dynamic(EHD)lubrication model for the turbocharger’s floating ring bearing was established to calculate inner and outer oil films’pressures,rotor vibration characteristics and turbocharger housing’s surface vibration velocity.The calculation results were verified with test ones.The results showed that the modeling method adopting the flexible multi-body dynamics and the EHD bearing lubrication model can be used to effectively analyze the turbocharger vibration characteristics;this method provides a theoretical basis for studying turbocharger’s synchronous vibration,sub-synchronous one and noise problem.