The rebound of non-spherical particles in gas-turbine components

Particulate deposition is known to cause significant damage gas turbine components. Modelling the location and quantity of desirable optimise component geometry quantify cost ownership effects that arise from ingestion atmospheric contaminants. Previous work has shown particle trajectory angular velocity post-rebound – following collisions with a wall - can have profound effect on likelihood subsequent downstream deposition. Therefore, accurately predicting rebound particles crucial model trajectories, erosion Current bounce-stick modelling generally assumes presence spherical are not representative real contaminants at point impact substrate. This uses FEA simulations compare spheroids different aspect ratios spheres, hence assess applicability, errors, associated use spheres in models particulate collisions. Simulations were performed 3D prolate 1.9 4.6 colliding half-space orientation angles relative surface. The spheroid geometries typical some observed particulates. In all major axis was taken lie axial flow normal plane, consistent simple fluid drag considerations, previous observations. Oblique modelled ANSYS Mechanical validation obtained by comparison predictions experimental data for equivalent diameter similar material pairs. coefficients restitution velocities differ those vary significantly orientation. many instances, during first collision centroid does obtain away surface, leading multiple bounce events. Sensibly changed ratio causes magnitude increase after impact, occasion change its sign. will alter lift induced boundary layer rebound. this Normal (CoR) lower than while tangential CoRs higher, shallower trajectories post-rebound. physical mechanisms behaviour, how they be captured low order behaviour discussed.