Direct Numerical Simulation of Hot and Highly Pulsated Turbulent Jet Flows

In this paper, we present numerical simulations of highly pulsated jet flows at 12, 000 K developing in a colder environment. Such flows are used to model plasma jets generated by direct current plasma torch. Plasma spraying is used to deposit thick coatings on a substrate. We focus here on situations where plasma jets are randomly forced by an electric arc resulting in a highly turbulent flow at large Reynolds number. DNS were performed for different ambient temperatures T-infinity >= 6, 000 K. For T-infinity = 3, 000 K, the use of a high-order explicit filter was necessary in order to remove aliasing oscillations. The effects of T-infinity on the flow properties are discussed.