A hybrid mesh harmonic balance solver for the aeroelastic analysis of turbomachinery

Abstract

An implementation of a Harmonic Balance method to simulate time-periodic, non- linear flows in turbomachinery on hybrid grids comprising both structured and unstructured blocks is described. It has been developed with the aim to apply it to aeroelastic analysis prob- lems which require support for deforming meshes. The necessary modifications of an existing implementation of a Harmonic Balance method on structured grids are presented. Especially block boundaries require a separate treatment. For the same spatial discretization order the solver for unstructured grids requires a moderate overhead in computational resources in terms of computation time compared to the structured solver when applied on grids with similar spa- tial resolution. The extended HB solver is applied to a standard turbomachinery aeroelastic test case for inviscid flows including both subsonic and transonic configurations. The computational results obtained are compared with results from a Harmonic Balance solver for structured grids and references from literature.