Research On Vibration Characteristics And Damping Optimization Of Bladed Disk System In Compressor

Bladed disk structure belongs to the cycle symmetric structure, commonly used in aero-engine and steam turbine. In aerospace, bladed disk as the core component of an aircraft engine, its vibration condition affects the normal work of the engine. Due to the mistuned widespread existence of the bladed disk, the cyclic symmetry of the system is destroyed. It induces the high cycle fatigue damage of the rotor blades, which greatly threaten the safety of the aircraft engine. So it is necessary to study the vibration characteristics of bladed disk.In this paper, a bladed disk system in the compressor as the research object, the vibration characteristics of bladed disk system is analyzed under different conditions. The influence of different system parameters on the vibration characteristics is studied, and the blades of bladed disk system are sorted based on intelligent optimization algorithm. The vibration of tuned and mistuned bladed disk system is simulated by different analysis methods. It mainly includes the following several aspects:First of all, the nonlinear vibration equation of the blade disk system is established based on the lumped parameter model, and the vibration localization of the blade disk system is analyzed. The influence of incentive order on the vibration characteristics of the tuned system is periodic, but this periodic is broken due to the mistuned blade. The effect of different mistuned blade position(according to sine wave and rectangular wave changes) on the vibration of bladed disk system is studied. The order arrangement of the mistuned blade is optimized based on intelligent optimization algorithm,and the damping effect is achieved.Next, the mechanical properties of single blade are analyzed by the finite element method. The mechanical properties of the blade under different loads were studied, including centrifugal force, aerodynamic force and the coupling of centrifugal force and aerodynamic force. It is found that the aerodynamic load effect can offset part of the centrifugal load. The effect of temperature change on the vibration modal of blade is analyzed. The result shows that the natural vibration frequency of the blade decreases with increasing temperature.Finally, In order to save the great computation effort for the vibration characteristics analysis of whole mistuned bladed disk model, an improved CMS super-element method is proposed. The vibration characteristics and dynamic response of mistuned bladed disk system are analyzed based on the improved method. The result shows that the resonance peak is increased due to the mistuning.In summary, the research results of the vibration characteristics of bladed disk system can provide a reference for henceforth development of the vibration localization theory, and provide a certain theoretical basis for the design of bladed disk system in the compressor.