Numerical study of particle transport and deposition on a film-cooled flat plate under conjugate heat transfer conditions

This study employs numerical simulations to investigate particle transport and deposition on a multi-row film-cooled flat plate. The flow field is resolved using the RANS method with the Realizable k–ε turbulence model, and particle–wall interactions are modeled using the critical velocity deposition model. After grid independence tests and model validation, particle behavior in the 1–12 μm size range is compared under adiabatic and conjugate heat transfer (CHT) conditions. Further analyses explore the effects of wall thermal conductivity (20–100 W/(m·K)) and blowing ratios (M = 0.5–1.5) within the CHT framework. Results show that deposition efficiency is significantly higher under adiabatic conditions due to elevated surface temperatures exceeding the deposition threshold. In contrast, the CHT model exhibits size-selective behavior, with downstream deposition primarily governed by the inertia of particles with diameters greater than 8 μm. As thermal conductivity increases, deposition efficiency decreases due to weakened thermal gradients and reduced thermophoretic forces. Although higher blowing ratios enhance particle impingement, such ratios reduce capture efficiency due to lower wall temperatures. These findings improve the understanding of particle deposition mechanisms under film-cooling conditions and highlight key parameters influencing deposition control.