Analysis on aerodynamic stability of super-long last-stage blades of a nuclear turbine by fluid-structure coupling method

A 3-D time-domain approach based on fluid-structure coupling by solving the RANS governing equation is carried out to analyze the aerodynamic stability of super long last-stage blades of a newly developed nuclear turbine. The unsteady analysis under a design and two high-backpressure conditions are achieved and the results show that the amplitudes of blade vibration curves are all attenuating with the first natural frequency under the three backpressure operating conditions, which numerically proves that the newly developed turbine blades will maintain aerodynamic stable and there is no flutter up to the 10800 Pa backpressure condition. (authors)