Modeling and Control of a New Spray Process Combining Plasma and HVOF

This study deals with the numerical simulations and experimental observation of a new industrial thermal spray process developed at Inasmet Technicalia. The process, called “Oxi-Fuel Ionization” (OFI) combines a plasma torch with a combustion chamber and a nozzle. The plasma jet assists the combustion process; it makes it possible to stabilize it over a large range of fuel/oxidant conditions and also operate the gun with lower gas flow rates than conventional HVOF guns.

The mathematical model involves the formation of the plasma jet, combustion process and supersonic flow issuing from the spray torch.It examines the influence of the HVOF nozzle design on the velocity and temperature fields of the gas flow.

The model equations were solved using the CFD Fluent 6.3 code and the predictions were validated against experimental observations.