Mailing List flyrotary@lancaironline.net Message #40607
From: Ernest Christley <echristley@nc.rr.com>
Subject: Re: [FlyRotary] Re: Giving up on single rotor
Date: Tue, 04 Dec 2007 17:39:19 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Thomas Jakits wrote:
Lynn, Bill, George, Richard - anyone knows what I am talking about? Any
possible application for the 1-rotor?
Am I full of it??
  

This is one of many methods of dealing with torque reversals.  In this case is the idea that you do no pull backwards on the load.  You let the load fly ahead forward on its own.

The problem with this method is there isn any backpressure on the crank when the next cylinder fires.  The crank flies ahead and slams into the load.  I believe this makes the problem worse in most cases.

Al's method is the best way, as I see it.  An engine drives a load around a circle with a series of hammer pulses.  The object is to couple those hammer blows to the load with just enough spring that the blows even out to one long push.  The amount of spring needed relies on the rotational moment of the load, the spring's constant, and the spring's torque arm.  The rotational moment is static for a given propeller, and the constant and torque arm for the spring are nicely summed with a torque wrench.  A complete model would require measuring the amplitude and frequency of the hammer blows, but a graph built from a few experiments like Rusty conducted will allow one to plot where the system resonates and home in on an appropriate amount of spring.

Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster