**1. Usual high-level explanation**

Wikipedia explains air flow in a jet engine this simplified way:

[![enter image description here][1]][1]  
<sup>Flow path, [Wikipedia][2], author: Jeff Dahl</sup>

Not obvious on the picture, there is a stator with vanes after each rotor, to create the pressure increase on vanes pressure side, and to straighten the flow for the next stage of the cascade, else there would be no compression and the engine would be an expensive fan. See [this question][3] for a picture showing the stators.

----

**2. Taking into account blade and vanes**

Usual depiction of the path, taking into account blades and vanes is zigzagging, similar to:

[![enter image description here][4]][4]  

The path above seems valid for blades and vanes motionless, ignoring blades are in rotation. If we dive into a more detailed explanation, the path can be depicted like this:

[![enter image description here][5]][5]  

----

**3. Taking into account blade rotation**

However with blades rotation, the blade of the second stage *did* move, somehow carrying air with them (downwash), the flow now uses the next vane to exit the second stage. Air path is spiraled a bit, the exact amount of spiral depending of the ratio between air axial speed and blades rotation speed. This is depicted on the right hand image

[![enter image description here][6]][6]  

----

**4. Seemingly more consistent depiction of air path**

Therefore, if this is correct, the overall flow should be rather helical, something more like this:

[![enter image description here][7]][7]  

----

**5. Question**: How blades and vanes impact overall air path? How the air path can be better explained, taking into account blades are not fixed?

I'm looking for some details, perhaps blade/vanes geometry and airspeed, not an over-simplified view.


  [1]: https://i.sstatic.net/LheHE.png
  [2]: https://en.wikipedia.org/wiki/Turbojet
  [3]: http://aviation.stackexchange.com/questions/27446/how-is-the-central-hub-shaft-casing-of-a-two-spool-turbojet-assembled
  [4]: https://i.sstatic.net/dnM93.png
  [5]: https://i.sstatic.net/u45UG.png
  [6]: https://i.sstatic.net/rED07.png
  [7]: https://i.sstatic.net/ll7oB.png