Assessment of Scavenge Efficiency for a Helicopter Particle Separation System

The effectiveness of a helicopter particle separation system has been numerically assessed at practical operating conditions and sand environments for various scenarios. The particle separation mechanism and its limitations are revealed by the predicted flow field characteristics and particle trajectories. The separation-by-inertia concept is effective for removing large particles, but problematic for small particles of diameter ≤36 μm for the configuration and operating conditions considered in the present study. It is also found that particle size, shape factor, and rebound characteristics exert substantial effects on particle scavenge efficiency. However, the effects of gravity, particle inlet velocity, inlet mass distribution, and engine-operating conditions on scavenge efficiency are minor or limited. Finally, a few suggestions for further investigation on engine particle separation systems are included.