Piston engine with a ducted fan unit ?

[First time Juke]

Re: Piston engine with a ducted fan unit ?

I'm actually talking about a system with no fuel burned downstream of the compressor/fan.
All the propulsion would come from energy added directly by the fan.

My gut tells me there's a thermodynamic reason it's impractical, but I haven't done the math...

You're basically talking about a simplified version of a hybrid turbojet/ramjet (like the J-58), with the fan taking the place of the turbojet: i.e. http://www.aerospaceweb.org/question...on/q0175.shtml

Exactly..this is just a pricpipal idea how to feed the air for the ramjet..the channels etc would possibly need few experts and a wind tunnel and lotsa hard work to be operational.