Abstract: The present method and apparatus for producing a supersonic jet stream introduce an oxidizer in such a manner as to create a vortex, which is then restricted. Fuel is introduced into a reduced pressure eye of the vortex, forming a stratified composite stream of gases with unmixed oxidizer surrounding an inner mixture of fuel and oxidizer. This stratified composite stream is passed down a tube that exhausts to a low pressure environment. The combined fuel and oxidizer in the stratified stream is ignited to provide a high-velocity stream of combustion products. The outer layer of unmixed oxidizer in the vortex shields the tube and reduces or eliminates the need for additional cooling.