Blade Aeroelasticity Analysis Based On Fluid Solid Coupling

The research for turbo-machinery aero-elasticity is an important part of the study of fluid solid coupling. Aero-elasticity is the phenomenon which exhibits distinct reciprocal interactions between aerodynamic force on blades and vibration deformation. Flutter will occur when vibrating amplitude of blades increases continually.In this paper, aero-elasticity stability experiment of a flat plate cascade is carried out. Flutter process is observed and relationship between wall pressure response on top of blade tip and vibrating response of the blade is analyzed. Exhaustive analysis of fluid solid coupling and the process of numeric simulation are presented here. A numeric simulation approach by using CFX, ANSYS and a coupling platform between the two soft wares was applied for studying the fluid solid coupling. The aero-elasticity stability of the flat blade used in the above experiment is simulated using the approach. With different inlet velocities, displacement and pressure response are obtained. Feasibility of this approach is testified by comparing the calculation results with experiment results. Meantime, aero-elasticity stability of NACA0012 straight blade is also simulated by using the same approach. Flutter boundaries of the blade are acquired by correlating attack angle with inlet Mach number. And following conclusions are reached: changing trend of fluid pressure response on top of the blade is consistent with vibrating response of the blade. And both of the response frequencies are the same, which are fairly close to natural frequency of the blade. This provides a new idea of blade flutter prediction. In the end, aero-elasticity stability of compressor rotors is simulated. Steady fluid field characteristic,the vibrating characteristic and stress of the blade are analyzed.In this paper, fluid solid coupling simulation of blades and calculation results are useful for reference on blade flutter prediction and aero-elasticity analysis.