INFLUENCE OF TURBOSHAFT ENGINE ARCHITECTURE ON ASH PARTICLE DEPOSITION - REDUCED ORDER MODEL APPLICATION

Particles ingested by aer gas turbines are capable of melting in the combustor and depositing on high pressure turbine vane surfaces, where they degrade aerodynamic and thermodynamic performance. The extent of the damage caused is a complex physical process dependent on the thermal and inertial properties of the particles, the operating state of the engine and importantly, the engine architecture. The dominant architecture consideration is the distance between the combustor outlet and the position of the burner flames relative to the nozzle guide vanes’ leading edges. In this work, we investigate the influence of this on particle deposition by approximating the temperature variation of the hot streak as a sinusoidal profile. A parametric analysis is carried out using numerical simulations and an elasticplastic particle deformation model, to evaluate the effect of mean temperature, temperature gradient across the hot streak, and hot streak position on the deposition rate of a generic size distribution. Results show that the dominant effect driving particulate deposition is the mean temperature of the gas, but the rate of deposition on a vane may be reduced by up to 80% if the peak temperature emanating from the combustor is directed down the throat passage between adjacent vanes compared to being directed at the vane leading edge.