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Message
Maybe the low idle problem is related to the mixture
problem.
Hi
Bob,
The low speed problem is
known as "torque reversals" and would also effect single piston engines I
believe.
As I understand it, the
rotor fires, and accelerates the engine forward. Once the thrust from the
exhaust is over, it has to coast around part of the revolution to get back to
where it can fire again. While coasting, the compression for the
next cycle hits, and the engine starts decelerating, only to suddenly accelerate
again when it fires the next time. This torque reversal is what
causes the shake.
As you add
more rotors (or cylinders), then you get to a point where acceleration
is being generated by one rotor, while another is trying to decelerate from
compression. Since the firing pulse is so much greater than the
compression force, the net result is that you always have
forward torque.
The only way you can
smooth out a single rotor at low rpm would be to have a heavy flywheel.
The inertia from the flywheel would help you "coast" through the compression
stroke, and significantly reduce the deceleration. The downside is
obvious for aircraft applications.
Cheers,
Rusty
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