Vortex structures in supersonic jets exhausting into a submerged space

Results of studying gas flows in a setup used for cold gas-dynamic spraying are reported. The setup consists of a cylindrical inlet channel with a central rod connected at a right angle with a rectangular slotted channel. Injection of a high-pressure gas through the inlet channel leads to gas acceleration. It is shown that there are velocity and pressure disturbances in a supersonic overexpanded jet exhausting from the channel, which arise due to the presence of compression and expansion waves, as well as streamwise vortices. The contribution of streamwise vortices to pressure and velocity disturbances is approximately 30%. Streamwise vortices are formed at the entrance of the slotted channel owing to curvature of streamlines.