John, you say:
<begin quote>
Yes, it expresses a dP/dt view. No, it does not come close to
explaining why a reaction engine should exhibit translational lift.
Consider the counterargument: Reaction engines, according to the
definitions everybody else is using, don't exhibit translational lift!
Certainly Bill B.'s machine gun (which started this thread) doesn't.
Bottom line: there is a fundamental difference between the
*observable* behaviors of helicopters and reaction engines.
You haven't come even 1% of the way to convincing me that the physics
is the same when the observed behavior is so different.
<end quote>
This makes me reiterate what I said yesterday... we must have different
definitions of reaction engines. I was under the impression an engine
working by dp/dt was a reaction engine. That definition is fairly
broad and would include engines that do not behave identically. For
example, even machine guns and rocket engines do not behave
identically. Since the rocket exhaust is (for all practical purposes)
continuous, and the machine gun "exhaust" is discrete, the thrusts from
these two reaction engines are very different. Yet they are both
reaction engines, aren't they?
Since you say I am using dp/dt, but not a reaction engine, I guess I
need your definition of a reaction engine. While you're at it, could
you also tell me if you consider a jet engine as a reaction engine?
And how would a jet engine turned vertical compare to a helicopter?
Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817