Computations of aerodynmaic damping for blade vibrations in stall

摘要

The aerodynmaic damping of blade vibrations are claculated.THe resulting aerodynamic damping is affected by 1).the static aerofoil data used,2).dynmaic stall modelling and 3).mode shapes.A sensitiviyt study is carrried out and it is ofund that all three parameters are important.It is shown that the description of the blade oscillation in terms of how the blade deflectws is important.Specifically the aerodynamci dampoing of the lead-lag mode is found to be very sensitive to relatively small out of plane blade deflections.