Theoretical modeling and optimization study of particle acceleration and heating inside an electrothermal-chemical device

A theoretical model for the physical phenomena taking place in a new electr othermal-chemical device for thermal-spray coating is proposed. Inside this new device, the powder particles to be coated on various substrates are ac celerated and heated by a mixture of plasma and gases that results from the burning of an energetic propellant. The model is meant to be a tool for th e device work optimization in order to obtain high quality coatings. The eq uations are able to describe the hydrodynamic and thermodynamic characteris tics of the accelerating, gas as well as those of the accelerated particles . The results we obtained point to some special features of our thermal-spr ay device that are not common to other methods and devices currently in use . In the same time, it seems that using our model predictions, we may have the possibility to choose the proper input process parameters which would l ead to optimal thermal and kinetic characteristics of the accelerated parti cles at the device exit and finally to quality coatings. The model predicti ons for some flow and particle parameters such as: gas pressure and particl e velocity, are in good agreement with the experimental data.