Numerical research on the particle transport and deposition in the impingement-film cooling passage.

With the aim of exploring the particle transport and deposition characteristics in the internal cooling channel of turbine blades, the computational fluid dynamics-discrete element method is used to implement the numerical simulation of particle transport and deposition in the impingement-film cooling passage. First, the unsteady development process of the particle transport and deposition with the increase in injection particle mass is obtained. Then, the effect of jets Reynolds number, particle Stokes number, and initial particle volume fraction on the particle deposition characteristics is presented. Finally, the particle deposition mechanism in the impingement-film cooling passage of turbine blades is revealed. The results show that the conical-shape particle deposition layer is formed at the impingement stagnation point region and the banded-shape particle deposition layer is formed between adjacent impingement holes. The cooling gas carrying particles is injected from the impact hole and subjected to the fluid shear force. Then, the cooling gas carrying particles gradually developed into the conical-shape free jets. In addition, the symmetrical vortex structure is formed due to the collision of the adjacent jets. Therefore, the particle deposition layer is formed on the impingement target surface, which is caused by the energy attenuation due to the continuous collision of the particle with the particle and the particle with the wall. The increase in the jets Reynolds number inhibits the particle deposition behavior, and the increase in the Stokes number accelerates the particle deposition behavior. [ABSTRACT FROM AUTHOR]