Numerical simulation on particle deposition characteristics and mechanism of turbine blade with film cooling

Abstract

The ingress of particles into aircraft engines, leading to deposition on turbine blade surfaces, poses a significant threat to engine reliability by potentially obstructing film cooling holes. This paper investigated the deposition characteristics of C3X blades with film cooling, aiming to address the limitations of existing models and provide deeper insights into the underlying mechanisms. To achieve this, the existing deposition model was improved by incorporating the deposition rate and considering particle secondary collision-deposition based on EI-Batsh's critical velocity model, thereby enhancing prediction accuracy. Using the improved model, the effects of particle diameter and blowing ratio on deposition characteristics were systematically analyzed. Additionally, the dynamic mesh method was employed to simulate the morphology of the deposition layer. The result shows that the deposition mass peaks at a particle diameter of 6 μm, with multiple deposition peaks observed for particles larger than 8 μm. Increasing the blowing ratio promotes a more uniform deposition layer on the blade's leading edge while creating non-deposition regions on the pressure side. Notably, the blowing ratio has a more pronounced effect on larger particles (>6 μm), and appropriately increasing it can effectively reduce deposition. This work provides theoretical support for the subsequent prediction of sedimentary properties.