Leading micro eddys can solve this.
If the induction is a straight stream, it will fail - you need to direct micro eddys
If you do this with mechanical means (deflection cowlings) you will hit a limit.
The ideal design is in the funneling of eddys as they traverse in a super spiral between the front eddy and as it spirals to the thrust vector.
however, pre-ionizaton, and then magnetic ion direction can swirl the eddy to the desired output. However, AIR is not the thrust component at this time, its ionized energy which is being "thrust" (thrust is typically thought of as a 'push' - but this is actually a 'pull'
Identify a spot, pull yourself to it. As opp
Further, if you wer to dimple/convex in an alternating pattern the leading edge of any aero ... efficiencies would increase.
Micro-dimples are better.
Understand the eddys, as Da vinci would say....
Thus, the front prop gets almost 20% more torque than the rear prop.
0. https://aviation.stackexchange.com/questions/74787/why-dont-...
1. https://www.rcgroups.com/forums/showatt.php?attachmentid=281...
So hopefully you see how your question is an interesting one, and one that has already been sorta done. Turbofans and turboprops are really quite similar, but at mach speeds only the turbofans have the right environment to be able to work efficiently. Your idea would have the prop in a supersonic air stream, which would make it effectively useless.