Computational fluid dynamics evaluation of conditions before impact of particles in plasma spraying process

  • K J Mbwebwe Tshwane University of Technology
  • A Kolesnikov Tshwane University of Technology
  • I J Van Der Walt The South African Nuclear Energy Corporation SOC Ltd.
  • H Bissett The South African Nuclear Energy Corporation SOC Ltd.
Keywords: Plasma jet, Plasma spraying, Temperature, Velocity, Particles

Abstract

Plasma Spraying is one of the most sophisticated and versatile thermal spray techniques. In Plasma Spraying, powdered material is injected into a plasma jet, which is generated from a plasma torch. Upon contact with the plasma jet, the particles are melted and propelled forward onto a substrate to form an adherent coating which modifies the properties of the substrate. The modifications to the substrate can, for example, increase its resistance to other extreme operating conditions such as wear, abrasion, and corrosion. However, the phenomena governing the formation of the plasma jet inside the plasma torch and its subsequent interaction with injected particles are not fully understood. This paper provides a detailed report on steps taken for the development of a comprehensive numerical model to simulate plasma jet development inside a direct current plasma torch. The heat flow and mass exchange of ionized gas with injected solid particles were followed in three dimensions by using a Computational Fluid Dynamics (CFD) method. A cylindrical energy source term which was defined as an increasing linear function dependent on time as a variable, was included to reproduce the effects of an electric arc on the gas flow. For optimization purposes, it was sought to investigate the effects of the particles’ injection angle and inlet velocity, as well as the effects of particle size distribution on the particle temperature and velocity histories.

Author Biographies

K J Mbwebwe, Tshwane University of Technology

Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria 0185, South Africa

A Kolesnikov, Tshwane University of Technology

Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria 0185, South Africa

I J Van Der Walt, The South African Nuclear Energy Corporation SOC Ltd.

The South African Nuclear Energy Corporation SOC Ltd. (Necsa), Elias Motsoaledi Street Extension (Church Street West) R104 Pelindaba, Madibeng Municipality, North West Province, 0240, South Africa

H Bissett, The South African Nuclear Energy Corporation SOC Ltd.

The South African Nuclear Energy Corporation SOC Ltd. (Necsa), Elias Motsoaledi Street Extension (Church Street West) R104 Pelindaba, Madibeng Municipality, North West Province, 0240, South Africa

Published
2022-01-24
How to Cite
Mbwebwe, K., Kolesnikov, A., Van Der Walt, I., & Bissett, H. (2022). Computational fluid dynamics evaluation of conditions before impact of particles in plasma spraying process. Suid-Afrikaans Tydskrif Vir Natuurwetenskap En Tegnologie / <i>South African Journal of Science and Technology</I&gt;, 40(1), 16-21. Retrieved from http://satnt.co.za/index.php/satnt/article/view/871
Section
Conference of the South African Advanced Materials Initiative

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