Effect of Aerodynamic State on Excitation Force and Vibration of the Turbine Blade

A turbine with high cycle fatigue failure was used as the simulation model, the coupling method of three-dimensional unsteady flow field and solid vibration response analysis was adopted, the simulation of fault point was carried out. According to the different conditions of turbine expansion ratio and turbine reaction force, the law of aerodynamic load distribution and aerodynamic exciting force caused by aerodynamic state change was compared, at the same time, the relative variation trend of blade vibration stress was obtained. Results show that under unchanged intake conditions, the average exciting force, the amplitude of exciting force and the vibration stress of the blade increase obviously with the increase of the expansion ratio of the turbine. While the turbine reaction force increases, the average aerodynamic exciting force of the blade increases obviously, but the amplitude of the exciting force and the vibration stress have a downward trend.