Unveiling particle deposition characteristics on flat plate with a shaped film cooling hole

•The multi-perspective scanning (MPS) method based on the structured light was proposed for the measurement of deposition topography. It was inferred from validation experiment that it could reach the accuracy less than ±0.05 mm.•Tow typical film cooling holes were conducted for experimental studies with the MPS method to characterize the process of deposition formation and deposition topography at various blowing ratios. Deposition results show that the 777-shaped hole has a better performance of reducing particles depositing downstream from film cooling hole than the cylindrical hole. After 30 min, it can make an approximate 10–40% reduction of area-averaged deposition thickness.•Combined with the analysis of the flow field obtained by computational simulations, the trajectories of particles that move to the region near the hole are affected by cooling jet. Some particles are lifted by the injection flow, and some particles are entrained by the counter rotating vortex pair (CRVP). The pattern of particle impact efficiency supports this observation. 777-shaped hole reduces particle deposition mainly by reducing the impact efficiency. Particle deposition on turbine blades poses a significant challenge to the safe operation of gas turbines. The blockage of film-cooling holes and alteration in the aerodynamic shape of blades affect the turbine's efficiency, highlighting the importance of reducing particle deposition on turbine blades. To investigate the characteristics and potential mechanisms of deposition, experimental and numerical studies were conducted on two typical film-cooling holes: cylindrical and 777-shaped. A multi-perspective scanning method was used to measure the three-dimensional deposition topography on flat plates under a particle-laden environment. The wax deposition experiments showed that the deposition thickness of both holes increased with the blowing ratio. However, the 777-shaped hole exhibited a 10–40% reduction in deposition compared with the cylindrical hole. The computational predictions of deposition patterns agreed well with the experimental results. The numerical simulations revealed that the presence of film cooling reduced deposition in some areas but increased deposition in the vicinity of the film coverage region owing to the entrainment of vortices. Overall, this study further elucidates particle deposition characteristics and the influencing factors, which can guide the design of blade cooling systems with reduced deposi