Modelling rotor-rotor interaction on reduced passage counts using a time-domain Fourier approach

Authors

S.C. Stapelfeldt, L. Di Mare - Imperial College London, United Kingdom

Abstract

Blade row interaction is known to significantly affect aerodynamic performance and aeromechanical stability. Multi-stage flows can be modelled accurately on the whole annulus multistage domain. However, full circumference time-accurate simulations remain expensive and unpractical in the design cycle. This paper uses a time-domain Fourier based method to model steady and unsteady interaction effects in a 1.5 stage compressor. The method was developed for general non-axisymmetric flows across multiple blade rows. The computational domain includes several passages which are distributed over one wavelength of the fundamental stationary disturbance and act as sampling points for a circumferential Fourier transform. Flow variables at the pitch-wise boundaries and inlet/exit surfaces are updated from circumferential and temporal Fourier approximations. Results from the reduced passage model and whole annulus solutions are compared in terms of unsteady and time-averaged loads. The results demonstrate that the time-domain Fourier approach is capable of capturing steady and unsteady blade row interaction effects.