Effects of uneven blade spacing on unsteady blade forcing in an axial compressor

The influences of unsteady blade forcing over the blades in an axial compressor with unevenly-spaced blades was investigated by numerical method. The quasi three-dimensional unsteady Navier-Stokes equations were solved with high-resolution scheme. Dual time-stepping approach in conjunction with LU-SGS implicit method was used to solve the unsteady flow fields. The main effort is focused on a compressor stage with IGV. The uneven pitch spaces of stator blades and IGV are set in this stage. The numerical results predicted no significant influence on the aerodynamic performances. But the unsteady force over the rotor blade can be decreased with a certain configuration of uneven placed stator blades and IGV. The results show the benefit to the life of compressor rotor blades for the adoption of uneven space stator blades.