2022/10/10 by Tao Zhu, Margarita Baeva, Holger Testrich +2 · 1 voice
Engineering · #Fluid Dynamics and Heat Transfer #High-Temperature Coating Behaviors #Particle Dynamics in Fluid Flows
paper · pdf · doi:10.1007/s11090-022-10290-y
openalex publication_date 2022/10/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Abstract The work is concerned with the effect of a spatially fluctuating heating of Al 2 O 3 particles with diameters of 5–120 μm during a plasma spray process. A plasma jet is generated in a mixture of Ar (40 NLPM) and H 2 (14 NLPM) and in pure Ar at an electric current of 600 A. The tracing of the injected particles in the plume region of the plasma jets is considered in the framework of a three-dimensional model taking into account a turbulent fluid flow. It is shown that the heat source for the injected particles exhibits a well pronounced spatially fluctuating structure due to the enhancement of the thermal conductivity resulting from dissociation and ionization of the molecular gas in the temperature range of 2500–4000 K and 13,000–14,000 K, respectively. During their travel towards the substrate, the particles are therefore repeatedly heated in the gas mixture in contrast to the case of pure argon. Particles injected in the gas mixture reach the substrate with a higher average temperature and velocity.