Mistuning Blade-Disc Vibration Characteristics in Multi-Field Coupling Load Based on Kriging Model

In this research, a new approach is put forward that mistuning vibration characteristics are analyzed at the effect of aerodynamic and structural coupling. A compressor blade-disc system is taken as the research object. The models of flow field and mistuned blade-disc are established. Considering the interactions of stator-rotor blade rows, the compressor flow field is simulated with the Fluent software. Combining the methods of a static frequency test, dichotomy, and finite element analysis, the mistuned blade parameters are identified successfully. Based on Kriging interpolation method, load transfer of aerodynamic pressure and blade deformation is achieved. Then the paper analyzes the distribution law of aerodynamic load on the compressor blade surface. In addition, the effects of mistuning and aerodynamic pressure are discussed with the vibration characteristics of a blade-disc system. The results show that a load transfer based on the Kriging model has a higher precision; it can meet the calculation requirement for aerodynamic and structural coupling dynamics. The dominant frequencies of unsteady aerodynamic pressure are mainly at the frequency doubling stator-rotor interaction, especially at one time frequency (1 x f(0)). Variations of aerodynamic load take the contrary trend on the pressure and suction surfaces, magnitude and pulsation amplitude on the pressure surface are far greater than that of the on suction surface. Mistuning and aerodynamic pressure enhance the vibration nonuniformity of the blade-disc sectors. This research provides the theoretical basis for the dynamics design of a compressor blade-disc system.