From the information given in this thread I've come to this conclusion.....

A) Thrust can me maintained or even augmented to some degree with a cone shaped pipe vs a straight pipe....AKA the Wren pipe...

B) Thrust is lost through temperature decreases in the pipe....



My idea to reduce thrust losses is to come up with a pipe that is cone shaped and retains most of the turbine efflux heat without transferring excessive heat to the airframe.....

How about this....A cone shaped pipe like Wren Turbines has developed wrapped in a ceramic blanket instead of being of dual wall construction. The ceramic blanket would actually help retain heat in the pipe but provide enough of an insulating value to not transfer excessive heat to the airframe----

How about it?????

Kevin