Research on particle deposition characteristics and film cooling performance of trench flat plate with mesh morphing

Particles carried by gas and impurities in the operation environment can deposit on turbine blades. The deposition of particles on high temperature turbine can seriously damage aerodynamic efficiency and cooling characteristic. For preventing the negative effect of particle deposition, numerical simulations are used to investigate particle deposition and the influence of deposition on cooling performance of the flat plate by embedding the cooling holes into the trench. In the study, the Euler Lagrangian method is chosen to track particles. A hybrid deposition model based on critical velocity model and critical viscosity model is developed to estimate particle deposition by User Defined Function (UDF) of FLUENT. Dynamic mesh morphing is used to simulate the surface changes caused by deposition. It is mainly explored the differences in trench and blowing ratios. The effect of particle deposition on film cooling effectiveness is taken into account. The result shows that deposit efficiency of models with and without trench decreases with increasing blowing ratio. Deposit efficiency is highest when blowing ratio is 0.5, which can reach 17.8%. Trench can reduce or avoid the occurrence of certain deposition and effectively enhance the effectiveness of film cooling. Deposition can’t significantly weaken the cooling effectiveness.