You're right I did misspeak about the definition of a impeller/turbine. Never is a strong word though and there are such things as turbine pumps which are not

You're right I did misspeak about the definition of a impeller/turbine. Never is a strong word though and there are such things as turbine pumps which are not true turbines[0]. As far as I can tell they've never been used for engine applications. Regarding pumps they operate on a fluid, of which air is definitely classed as. [1] [0] https://www.globalspec.com/learnmore/flow_transfer_control/pumps/turbine_pumps https://www.globalspec.com/learnmore/flow_transfer_control/p... [1] https://en.m.wikipedia.org/wiki/Pump https://en.m.wikipedia.org/wiki/Pump