Re: Tip nozzle paradox

Apologies for not changing the title on my last post on this.

<<The engine doesn't accelerate past v because the net forces all balance.>>

Okay, in an "ideal" drag=free system, thrust increases with centrifugal force 
as chamber pressure, etc., increase.  
The specific kinetic energy of the propellant in the inertial frame must 
increase as it flows to the tip engines, and this energy must be supplied by 
engine thrust, so I suppose (without doing the calculus--no time, sorry) that at 
some tip velocity, all the thrust of the tip engines is needed to bring the 
propellant up to that tip velocity.  

But there is no apparent reason for that tip velocity to equal the exhaust 
velocity "v", and I should think the ultimate tip velocity would be very much 
higher.  

The kinetic energy of the exhaust in the inertial frame should equal the 
chemical energy of the propellant-which, at a large distance, would be apparent as 
a positive radial velocity of propellant mass increments moving outward in 
spiral waves.  This seems not that much different from what happens in a lawn 
sprinkler, except that some of the exhaust energy comes from chemical reactions 
rather than feed pressure. 

Globally (imagine an opaque Gaussian surface around the system with 
propellants going in and exhaust going out), it would be as if the same propellants 
were exhausted through a non-rotating engine with a radial nozzle.    

--Best, Gerald