Dust transport investigation in ribbed cooling duct integrating temperature-dependent elastic-plastic particle collision model

Abstract

The transport of micron-sized sand particles in the ribbed cooling duct of the turbine blade determines its deposition characteristics. This paper establishes a prediction function of the coefficient of recovery for 1–20 µm sand particles impact to DD3 Nickel-based single crystal superalloy, varying with impact velocity, impact angle, particle size, and temperature, based on the temperature-dependent elastic-plastic particle collision model. The fitted COR function is evaluated to be accurate and efficient. Then, studies the transport and accumulation of micron-sized sand particles in the ribbed cooling duct with gas-particle two phases flow method considering particle-wall collision, drag forces, pressure gradient forces, etc., of which the particle-wall collision predicts by the established function. Results quantify the significant effect of rib structure on flow features and transport of sand particles transport in the cooling duct, particularly for particles below 10 µm. The transport of fine dust is dominated by the turbulent flow dynamics and particle-wall collision, leading to severe particle accumulation at the rib-wall junction. Particles accumulation nearby the ribs is sensitive with the sizes, and the number of the accumulated particles increases slightly with the increase of temperature from 1,073 K to 1,273 K.