Turbocharger Rotor-bearing System Dynamicsanalysis Based On ANSYS

Turbocharger is a component that can improve the engine power and reduce the fuelconsumption by increasing the density of the air in the cylinder and increasing the burningefficiency. With it is widely used in the automotive and aerospace field, people pay moreattention to its durability and stability, when it is used. Thus, it is meaningful to study theaerodynamics in its rotor system.Based on the simulation study, For certain turbocharger rotor system model dynamics,mathematical model is established.And its modal;unbalance response;stability is analyzed.Firstly,the method of mathematics modeling of rotor support system is illustrated inrotor dynamics calculation.Based on discrete modeling ideas,some theoretical formulas areconducted in quality of stepped shaft lumped method and the simplified model of thebearing. The solving solution to equation of motion and critical speed in rotor-bearingsystem is deduced with finite element analysis.Secondly, With the help of solidworks, the solid model of the rotor-bearing system inTurbosupercharger is built. Through the model analysis, its critical speed is calculated.Comparison with experimental results,simulation results are demonstrated.It is suggestedthat its working frequency and2ndorder critical speed are too close.Simplified model inrotor system is conducted, according to that, the influence of the turbine impeller materialdensity, bearing span and bearing stiffness to critical speed is analyzed. And whenk105Nm, its working speed is far away from the critical speed in rotor system.Finally, using the finite element thought,build rotor unbalance response dynamicsmathematical model for the model simplified.Using finite element analysis software ANSYS, rotor-bearing system unbalance response is analyzed. Solved its unbalancedresponse under steady-state and transient effects. Unbalanced force obtained its response tomeet the work requirements of the conclusions.The factors are discussed that cause the rotorsystem instability phenomenon occurs.Take the Jefcott rotor into account to study thecauses rotor instability occurs. By viscous damping system model, given its stability andinstability criterion for solving speed and gives the general rule.And the instability speed iscame to conclusion.