Modeling of the time-dependent aerodynamic characteristics of a rotating blade row (Q1571183)

A Green function is constructed for a linear Helmholtz-type elliptic-hyperbolic equation that describes the amplitudes of acoustic perturbations developing in an unbounded swirling background flow. The Green function is used in computing by the method of integral equations the time-dependent flow past a rotating row of slender weakly loaded blades in a uniform unbounded background stream characterized by a subsonic relative velocity over the entire blade span. A hypersingular integral equation for the potential jump across a blade is solved by a version of vortex-lattice method. Numerically examples demonstrate the convergence and capabilities of the method.