Effect of turbulence modulation on three-dimensional trajectories of powder particles in a plasma spray process

Due to complex interactions among the plasma jet, the coating powder particles and the carrier gas orthogonally injected into the plasma, the numerical simulation of a plasma thermal spray coating process is very challenging. In this paper, we numerically solve the system of nonlinear and coupled pa...

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Bibliographic Details
Published in:Journal of physics. D, Applied physics Applied physics, 2014-10, Vol.47 (40), p.1-24
Main Authors: Shang, S, Guduri, B, Cybulsky, M, Batra, R C
Format: Article
Language:English
Subjects:
Computational fluid dynamics
Fluid flow
Mathematical models
Modulation
Plasma (physics)
Three dimensional
Turbulence
Turbulent flow
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Summary:Due to complex interactions among the plasma jet, the coating powder particles and the carrier gas orthogonally injected into the plasma, the numerical simulation of a plasma thermal spray coating process is very challenging. In this paper, we numerically solve the system of nonlinear and coupled partial differential equations expressing the conservation of mass of species, the total mass, linear momentum and energy, as well as the k- epsilon turbulence model under pertinent initial and boundary conditions. The particle-plasma interaction is described by a drag force acting on particles and an equal and opposite force acting on the plasma. The lumped capacitance method is employed to model the particle heating and melting. Chemical reactions among species are considered. Whereas governing equations are written in the Eulerian description of motion, trajectories of powder particles are tracked using their Lagrangian description of motion. The mathematical model of the plasma process is validated by comparing computed results for the plasma, the particle temperature and the particle velocity with the corresponding test results taken from the literature. Significant contributions of the work include modelling effects of the carrier gas and the turbulence modulation introduced by particles which have not been considered in most previous two-dimensional and many three-dimensional studies. It is found that the consideration of turbulence modulation reduces the turbulent kinetic energy and its dissipation rate by more than 30% and 40%, respectively, in regions where particles are concentrated.
ISSN:0022-3727
1361-6463