An Investigation in the Variance in Particle Surface Interactions and Their Effects in Gas Turbines

This work presents the results of a study conducted to investigate particle surface interaction characteristics and their effects on the particle dynamics and blade erosion in axial flow gas turbines. The particle restitution velocities measured experimentally using Laser Doppler Velocimetry in a special tunnel are analyzed using statistical methods. The resulting distribution functions of the rebounding particle velocities after surface impacts are introduced in the particle trajectory simulations through the turbine blade passages, using a methodology that combines particle dynamics computations in a probabilistic model. The presented results for the simulated ash particle dynamics demonstrate the effect of the experimentally measured variance in the particle restitution characteristics on the particle surface impacts, and the associated blade erosion in an axial flow turbine.