| Civil aviation engine is a kind of rotating mechanical system with complex structure,and it is the power device of aircraft.As the core component of aircraft,its structural performance is the key factor affecting the safe operation of aircraft.With the development of aviation industry,the rotor structure of civil aviation engine is more and more complex,and the requirements for working stability are increasingly strict.In the production,design and working process of civil aviation engine,vibration problems are increasing and bring many adverse effects.Therefore,in order to ensure the working stability of civil aviation engine,how to reduce the vibration level has become a key issue to be considered in the engine design.In this paper,the high pressure rotor system of civil aviation engine is taken as the analysis object.By establishing the simulation dynamics model of the rotor system,the parameter sensitivity of the relationship between the bearing characteristics of the high pressure rotor and the rotor dynamics characteristics is studied.On this basis,the multi-objective optimization method was used to optimize the vibration reduction of the high pressure rotor system.Specific research contents are as follows:Firstly,considering the structure form and characteristics of the high pressure rotor system,a simulation model of the high pressure rotor system was established by using the finite element software ANSYS Workbench,and the dynamic characteristics of the rotor system(natural frequency,mode shape,critical speed and unbalanced response,etc.)were studied.Secondly,based on the above simulation results,the optimization objectives,optimization variables and optimization constraints of the high-pressure rotor system are analyzed and determined,and the optimization strategy of the rotor system is constructed.The Design Modeler module was used to parameterize the supporting characteristic variables of the highpressure rotor system,and the multidisciplinary optimization software i Sight was used to call ANSYS Workbench to conduct parameter sensitivity analysis on the supporting characteristics of the rotor subsystem,and the influence relationship between the supporting characteristics and the rotor dynamic characteristics as well as the interaction relationship between the supporting characteristics were obtained.Finally,based on the results of simulation analysis and sensitivity analysis of parameters,an approximate model between the optimization variables and the optimization target was established through Isight.With the critical speed as the constraint condition and the reduction of vibration level as the optimization objective,the supporting characteristics of the highpressure rotor were optimized,and the vibration reduction optimization of the rotor system was completed.The optimized high pressure rotor model was simulated and analyzed,and the modal characteristics and unbalance responses before and after optimization were compared to verify the optimization effect.Sensitivity analysis and optimization design of the support characteristic parameters of the high pressure rotor system to reduce the vibration level of the high pressure rotor are helpful to better clarify the influence of the support characteristics on the vibration level of the aeroengine,and provide a new idea and method for the vibration control of the aeroengine. |
