Characterization of particle rebound phenomena in the erosion of turbomachinery

The rebound of solid particles on material surfaces typical to jet turbines is predicted to assess the frequency of multiple impacts and secondary erosion. The numerical solution models boundary-layer growth, separation, and unsteady wake effects in the gas flow. The microgeometry of the surface is taken into account via experimentally determined statistical boundary conditions applied to the particle phase. The three types of rebound phenomena identified include imbedment, single-impact rebound, and multiple impacts, which appear similar to the way a stone skips across water. The momentum change after impact is characterized with respect to primary and secondary erosion mechanisms. The secondary erosion is found to increase with particle size. This result is in part an aerodynamic effect.