Effect of Flow Swirling on the Subsonic Air Jet in the VGU-4 HF Plasmatron

The effect of taking into account stream swirl when calculating the flow of a subsonic air plasma jet past a cylindrical model of 50 mm in diameter when the jet flows out from the discharge channel into the test chamber of the VGU-4 IPMech RAS HF plasmatron is studied. A comparison has been made of calculations of axisymmetric flow past the model based on the full Navier–Stokes equations taking into account (new results) and without taking into account (old results) the tangential velocity component w under the experimental conditions at a pressure of 80 mbar in a wide range of anode supply power at various distances from the plasmatron channel outlet to the model. It is shown that when calculating the VGU-4 plasmatron for a low power with taking into account flow swirl, the pattern of flow past the frontal part of the model is modified, namely, a vortex region is formed in front of the model instead of a relatively thin boundary layer. For moderate and high plasmatron power, the effect of taking into account swirl on the isolines of the dimensionless stream function and on the isotherms is small in the jet core region in front of the model, but is significant in the outer flow region in the test chamber.