Mechanism study on particle deposition and clogging characteristics in film cooling hole

Abstract

The present study is focused on the problems of gas–solid two-phase flow transport in the film cooling hole that cause film flow obstruction and cooling failure. To study the unsteady development process of the deposition layer in the film hole, a simulation method combining computational fluid dynamics and the discrete element method was used, and a film hole flow model was established. The effect of gas phase and solid phase characteristics on clogging and deposition in the film hole was studied. The following conclusions are drawn: The inlet/outlet pressure ratio is inversely proportional to the clogging degree of the film hole. The inlet/outlet pressure determines the deposition behavior by affecting the initial momentum and drag force of particles. In the Stokes number range of 1.58–14.26, the deposition in the film hole first increases and then decreases. There is a Stokes number with the most severe clogging. The Stokes number determines the deposition pattern by affecting the relative magnitudes of the drag force and interaction forces of particles. The particle surface energy is positively correlated with film hole clogging. The particle surface energy determines the stability of the deposition layer by influencing the strength of the force chain network.