Good point. The analogy was to what is called "suction cavitation" which can happen with vacuum pumps. However, there must still be a liquid vapor present for that to happen.
But this is in dry desert, correct ? There isn't enough water vapor for "suction cavitation" unless the turbulence of the blades is sucking the engine exhaust back into the vortex. One second thought, let's forget cavitation - and ask "is sonoluminescence possible from extreme turbulence in air and dust alone" ? There is triboelectric charge in there too. In fact, that frictional charging is probably most of it. -----Original Message----- From: Stephen A. Lawrence Waitaminnit -- cavitation in *air*? I thought you needed an incompressible fluid -- i.e., a liquid -- to get cavitation, or at least to observe the effects commonly associated with cavitation.
