Numerical study of instability development in supersonic jets with a rectangular cross section

The development of instabilities in supersonic perfectly expanded jets exhausting from nozzles with square and rectangular cross sections into an ambient flow is studied based on the numerical solution of the Navier-Stokes equations. The simulations are performed for various Mach numbers of the jet and the ambient flow. The results of numerical calculations make it possible to identify qualitative and quantitative differences in instability development in cases with supersonic and subsonic air flows, as well as characteristic features of the flow for rectangular jets.