Influence Of Heat Effect On Turbocharger Dynamics

The wide use of turbochargers has played an obvious role in promoting the development of industry.But in the actual industrial field,turbochargers can also cause various faults because of different working environment.Because the rotor system of turbocharger works in high temperature environment for a long time,it will be subjected to uneven temperature load due to air convection during cold car or start-up.The uneven temperature distribution will inevitably lead to the thermal bending deformation of the rotor system.At the same time,because the rotor system is subjected to great thermal stress,the dynamic characteristics of the rotor system will inevitably change because of the existence of thermal stress.Therefore,it is very important to study the causes of thermal bending and deformation of rotor system,the influence of thermal stress on the dynamic characteristics of rotor system and the harmonic response analysis of rotor system.Based on finite element simulation software ANSYS the causes of thermal bending,deformation law and sensitive parts of rotor system are studied.Secondly,the modal analysis of rotor system is carried out,the critical speed and mode shape of rotor system under each thermal stress load are solved,and the influence of thermal stress on the dynamic characteristics of rotor system is obtained.At the same time,the effects of uneven thermal field,uniform thermal field and thermal bending deformation on the stiffness of rotor system are studied.Finally,the harmonic response analysis of the rotor system is carried out,and the correctness of the critical speed of the rotor system is further verified by the frequency of the maximum amplitude of the rotor system.Considering the randomness of the unbalanced force of the rotor system,the influence of the magnitude and position of the unbalanced force on the harmonic response analysis is studied.The results show that the maximum temperature distribution of the rotor system is in the middle position of the rotor system,and the temperature load of the rotor system increases with the increase of the boundary temperature;the deformation of the rotor system near the turbine end is the largest and the main deformation form is axial deformation;The magnitude of unbalanced excitation force will affect the peak value of vibration displacement of rotor system,and the change of position of unbalanced excitation force will affect the vibration frequency of each position of rotor system.