Stress-vibration Failure Calculation And Analysis Of Vehicle Turbocharger Impeller

With the rapid development of the vehicle technology,the performance requirements of the power,economy and discharging of engines are further improved.The impeller which is the core component of a turbocharger for gasoline engine,can easily produced failure destruction under high temperature,high pressure and high load condition for working long time.The research of the stress-vibration failure of the impeller is benefit to improve the safety and reliability of the turbocharger.In this paper,the impellers of a vehicle turbocharger were studied through finite element method.Stress and vibration failures of impellers were calculated and analyzed on multiple load conditions,which laid the foundation of stress and vibration safety and reliability analysis of impellers.Specific research contents are as follows:Firstly,working conditions and load characteristics of the turbocharger were comparatively analyzed between the gasoline engine and diesel engine.The assessment method of gasoline engine turbocharger impellers stress-vibration failure was researched,which provides the basis for the stress-vibration failure judgement.Secondly,the effects of different loads on stress distribution of a gasoline engine turbocharger impeller were discussed using ANSYS Workbench.Based on the different load conditions and taken multi-field coupling into consideration,the stress of the impeller was analyzed in the near blocking point,the maximum efficiency point and the near surge point.The maximum equivalent stress location and the strength of the impeller were verified.And the specific reasons were analyzed combined with the flow field.Based on the results,the stress of the impeller was verified,and a method was presented.Finally,the modal analysis of the turbocharger impeller was presented to discuss the impeller vibration safety.The frequency and mode shapes of the impeller were obtained.The resonant region was analyzed and empirical formulas were verified.The effects of the centrifugal load,the thermal load and the aerodynamic load on the vibration performance of the impeller were discussed based on CFX calculation results,and the specific reasons were analyzed.