ISSN Online: 2379-1748
8th Thermal and Fluids Engineering Conference (TFEC)
SIMULATING THE PLUME QUENCH FOR PLASMA SPRAY APPLICATIONS
Аннотация
Plasma sprays can be used to melt particles, which may be deposited on an engineered surface to apply unique properties to the part. Because of the extreme temperatures (>>3000°C) it is desirable to conduct the process in a way to avoid melting the parts to which the coatings are being applied. A jet of ambient gas is sometimes used to deflect the hot gases, while allowing the melted particles to impact and adhere to the substrate. This is known as a plume quench. While plume quenching is done in practice, to our knowledge there have not been any studies on how to apply a plume quench, and how it may affect the flows. We have recently adapted our fire simulation tool to simulate argon plasma sprays with a variety of metal particles. Two nozzle conditions are considered, with very different gas flow and power conditions. Two particle types are considered, Tantalum and Nickel. For the model, the k-epsilon turbulence model is compared to a more dynamic TFNS turbulence model. Limited data comparisons suggest the higher-fidelity TFNS model is significantly more accurate than the k-epsilon model. Additionally, the plume quench is found to have a noticeable effect for the low inlet flow case, but minimal effect on the high flow case. This suggests the effectiveness of a quench relates to the relative momentum of the intersecting gas jets.