Patent ID: 10202965

Abstract:
A method is disclosed for estimating the surface condition of a blade rotating about a rotational axis in an air or fluid stream. The method involves measuring blade deformations indicative of blade loads acting on the blade to identify actual blade loads (P,R,T), measuring blade-state information (Ψ,Ω,,V) indicative of a blade operational state to identify a given blade operational state (α,Q), providing a clean-surface aerodynamic map (c) relating blade loads to an ensemble of blade operational states when the blade surface is in a clean state, providing a dirty-surface aerodynamic map (d) relating blade loads to an ensemble of blade operational states when the blade surface is in a dirty state, estimating the surface condition of the blade by comparing the distance of the actual blade loads (P,R,T) to the blade loads given by the clean-surface aerodynamic map (c) at the given operational state (α,Q), and the distance of the actual blade loads (P,R,T) to the blade loads given by the dirty-surface aerodynamic map (c) at the given operational state (α,Q).