Micron-Sized Particle Transport and Deposition in Internal Cooling Duct With Elliptical Pin Fins

Abstract

Abstract The particle deposition in the internal cooling duct reduces the heat transfer efficiency, increases the instability of aero-engine operation, and brings serious challenges to the design of turbine blades. In this paper, the energy dissipation collision theory is used to predict the particle transport and deposition in the cooling duct with different pin fins. The effects of pin aspect ratio and inlet Reynolds number Re on the deposition rate, as well as heat transfer efficiency and overall thermal performance, are investigated. The results show that the endwall deposition rate is much higher than the pin deposition rate. The pin adhesion rate decreases with the increase of inlet Reynolds number. Increasing Re has little effect on the endwall deposition rate for the cooling duct with pin fins of the aspect ratio of 1 and 1.5, while it leads to an increase in heat transfer efficiency and a reduction in pin deposition rate. For the cooling duct with pin fins of the aspect ratio of 2, the endwall deposition rate increases with the increase of Re. A larger pin aspect ratio decreases the heat transfer efficiency of the cooling duct, but increasing the aspect ratio is helpful to improve the overall thermal performance and reduce the deposition rate. To account for particle deposition and thermal performance, the aspect ratio of 1.5 is recommended.