Tracy Crook wrote:

Don't know if anyone has commented on this already Pete, but yes, the single rotor does have torque reversals. 

 

 Don't know how much of a problem this will be but the torque signature (IGNORE RPM FOR THIS COMPARISON, it doesn't matter)  will be the same as the three cylinder piston engine.  Raven had a challenging time developing a redrive for the Suzi/Geo 3 cyl. engine if that is any clue.

 

Tracy

If the two rotor is similar to a 4 cylinder 4 stroke piston engine, wouldn't a one rotor be similar to a 2 cylinder 4 stroke engine? Lamar has published the plots many times showing no torque reversals for a two rotor but very strong torque reversals for a one rotor.

-- 
Perry Mick
http://www.ductedfan.com

Ahh yes, the never ending debate on how to compare the rotary with a piston engine.  

 

The reason I said to ignore the rpm when comparing torque signatures was to compare ONLY the relative torque amplitude variation of the engines.  The two rotor engine looks just like a 6 cylinder in this respect.  Yes, I know the 2 rotor rotary only has two power strokes per rev but they are 50% longer (270 degrees vs 180) than those of a piston engine, thus, they overlap exactly like those of a 6 cyl.  This is relavant because tortional resonance has nothing to do with rpm that the system happens to be turning.

 

The torque variation represents the amount of excitation energy fed into the system.   The higher this energy, the more critical the damper is if the system has to spend any time at or near the resonant point.   In terms of this excitation energy, the one rotor probably has double or more  the amount that a 2 rotor has (all else being equal).  Notice that this excitation energy is not directly related to engine horsepower.

 

Somehow I doubt that I have made things any clearer.

 

Tracy