Modelling and simulation of multiphase flowing and depositing of YSZ coating on double-blade airfoil during 30Ar/60He PS-PVD Processing

Plasma spray-physical vapor deposition (PS-PVD) can produce yttria-stabilized zirconia (YSZ) thermal barrier coatings on complex gas-turbine components, but its non-line-of-sight capability does not automatically lead to uniform coating growth on rotating double-blade airfoils. The most severe deposition loss usually occurs in narrow inter-vane passages, where local geometry, accelerated flow, and low-temperature entrainment act together. In this study, a three-dimensional transient multiphase-flow model was constructed for YSZ particle transport and deposition under 30Ar/60He PS-PVD conditions. The inlet velocity and temperature fields were reconstructed from previously published numerical jet-field data instead of being simplified as uniform profiles. In addition, a User-Defined Function-based effective-deposition criterion was used to separate physically effective deposition from simple particle-wall collision.The simulation results show that, at 70 rpm autorotation, the substrate temperature rapidly enters a quasi-steady range of approximately 1000–1020 K. Meanwhile, a high-speed transverse shear flow develops inside the inter-vane passage and acts as an aerodynamic barrier against normal particle penetration. The predicted resulting of coating thickness distribution is highly non-uniform. At the windward leading edges, the maximum coating thickness reaches approximately 25 μm at 3.4 s and increases to about 42 μm at 8.5 s. In contrast, the shadowed inter-vane regions of coating remain only 2–4 μm at 3.4 s and about 11 μm at 8.5 s. During depositing, large particles are intercepted by the upstream vane, whereas small particles lose thermal state near the cooled boundary layer or are swept away by the near-wall shear flow. These findings identify the coupled geometric, thermal, and aerodynamic origins of deposition non-uniformity and indicate that improving PS-PVD uniformity requires coordinated control of particle state, jet direction, and substrate motion.