The vortex tube effect without walls

In a recent publication it was proposed that rotational cooling is due to angular propulsion. While this fact is obscured in a traditional shrouded vortex tube, it is clearly visible when the vortex tube effect is demonstrated without confining walls. It is thus established that the shrouded vortex tube behaves as a rotorless turboexpander, cogenerating both cold and hot gas. The physics of the turboexpander, the shrouded vortex tube, and the vortex without walls is shown to be governed by Eulers turbine equation. It is also concluded that propulsion generating vortices can exist without supporting or confining structures.