Importance of Preferential Segregation by Aerodynamics in Dust Rig Tests

This work studies a particle injection rig to understand how its design affects particle impingement and rebound from a target plate. The motivation behind this study is to understand how dust ingestion affects aviation gas-turbine engines. The particles are injected into a constant area duct upstream of the plate, and they exit through a converging nozzle. The major result concerns how particles respond differently to changes in the flow field based on their diameter. Near the plate, small particles follow the flow streamlines which causes them to both significantly slow down and to disperse in all directions. However, large particles move ballistically, so they impact the plate with nearly the same velocity and orientation they had at the duct exit. Reynolds-averaged Navier–Stokes (RANS) simulations are compared to large eddy simulation (LES). While RANS are capable of predicting mean particle impact statistics, they display narrower statistical variation than LES, suggesting that particle dispersion is underpredicted in RANS.