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Either I am going to have to stop talking with you guys all together or else
start talking to you a lot sooner on my projects {:>) Good idea, Jim, if I
say so myself.
The two tubes in my newest manifold design (after combining primary and
secondaries for each rotor) do telescope within one another. There is no
sealing at this point. IF you use tubing meant for telescoping you can get
it so that there is .0045 " clearance between the OD of inner tube and ID of
outer tube. Now this does not stop air leaks, but it sure slows it down.
You can maintain pressure in the tubes just with your breath. However, what
I next plan to do is to have the tubes nickle plated (as I did Tracy's
PSRU). Nickle it turns out has a property that is akin to lubrication
(Sorry not sure what the mechanism is) in that given Nickle's hardness and
this "Lubrication" property it would 1. prevent the aluminum from gauling
and 2. facilitate the tubes sliding and 3. If you coat with the right
amount you reduce that .0045" clearance even more. Now, my problem is I
don't know for say a 2" dia tube what clearance below .0045" might be fairly
air tight. As I said, the leak is slow enough with the .0045" that your
breath can maintain pressure in the tube against the leak. So that big pump
of an engine might not notice the leak at all except perhaps ad idle. If
thats not the case, then rubber booties like you suggest would probably
work.
So my two tubes have the plenum and throttle body with two injectors on the
one end and the lower manifold on the other. IF my concept for
self-alignment of the tubes work out together with my plan on using a ball
bearing draw-slide (or something a bit more expensive designed for this type
of thing) and mount the Plenum to the part that slides and the other end of
the drawer slide to the lower manifold. Then a screw driven by a 12V motor
would drive a "NUT" fixed to the plenum up and down on this track.
I really would like to use one of those electromechanicam actuators that
have the screw going throught the middle of the motor, but they are a bit
expensive.
I think I partially answered your last question, already. My design have
the two runners from each rotor "merged" into one tube for a total of two
tubes. In the automobile and with different port timing for primary and
secondary, the separate runners were just about necessitated. However, if
like with a turbo block or any block where the port timing is the same, then
I can no longer see any great advantage for separate runners. However,
merged or not, it does not change the pulse timing in the rotary for the
EDDIE. I don't quite see that your suggestion of a common plenum up close
and personal to the rotaries would work with the EDDIE. I'll have to give
it some thought.
Calibrate - based on manifold air temperature, Hummmm. Like I say - either
got to stop talking with your guys or talk with you a lot sooner {:>)
Some excellent ideas. Keep 'em coming.
Ed Anderson
Subject: [FlyRotary] Re: DIE the short Answer
> I was just yanking John's chain, but as long as we're here,
> let's progress a little. So you have to use something more
> substantial than a condom. Big deal. What if you made a
> telescoping section in the intake runner (much easier to do if
> the runner is straight :o) and a jack screw actuator (something
> like an electric pitch trim) to slide the upstream side of the
> runner out over the telescoping section. You could make it
> pretty loose so it wouldn't bind and then cover the telescoping
> area with rubber "accordion" tubing to prevent leaks. If you
> had an indication of how telescoped the intake runners are, you
> could calibrate it in Manifold Air Temp and adjust the length to
> match the MAT you're looking at at any given time.
>
> Tuned exhaust headers on 2-stroke motorbikes are tuned to an rpm
> and length so that a pulse will travel the length of the pipe at
> the local speed of sound during the period from one exhaust
> pulse to another. EGT and racing rpm in motorbikes is pretty
> stable, so one length will work. Intake temp is much less
> stable in a rotary engine, so variable length runners
> would be a must if you mean to avail yourself of the DIE effect
> under anything even remotely like typical operating conditions.
>
> Would it be possible to have an intake plenum at the block so
> that both rotors draw from the same runner? That would shorten
> the runner to half what it needs to be now, and make it easier
> to expand since you're varying the runner length by a percentage
> of itself. What is the engineering rationale for four intake
> runners to serve two rotors? Is it more important than DIE?
>
> But I've already told you more than I know ... Brain farts have
> that effect ...
> Jim S.
>
> Ed Anderson wrote:
>
> > Hey! I like it! Jim
> >
> > Has the appeal of simplicity, low cost and easily adjustable. Did
I, by
> > chance, ever mention that "Concepts are easy... the Devil is in the
> > details"?. Well, the first prong of the pitch fork I see with the
idea -
> > is - We somehow have to keep the lower pressure in the manifold (at idle
for
> > example) from sucking the rubber tubes closed. So the concept is ..err
> > great, err, but needs some more work on the details{:>)
> >
> > Ed Anderson
> >
> > ----- Original Message -----
> > From: "Jim Sower" <canarder@frontiernet.net>
> > To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> > Sent: Wednesday, September 24, 2003 10:12 AM
> > Subject: [FlyRotary] Re: DIE the short Answer
> >
> > > <... a way to adjust ...>
> > > Like an india rubber segment in the intake tubes. Attach to a big
lever
> > and
> > > stretch the intake out a little longer when the air is warmer :o)
> > >
> > > John Slade wrote:
> > >
> > > > > That is indeed the conceptual underpinnings of the EDDIE.
> > > > Cool. So all we need now is a way to adjust that timing on the fly,
that
> > way
> > > > we can have our cake and eat it while not having to worry about
precise
> > > > calculations and configuration issues that prevent us from
implementing
> > the
> > > > theory.
> > > >
> > > > >> Homepage: http://www.flyrotary.com/
> > > > >> Archive: http://lancaironline.net/lists/flyrotary/List.html
> > >
> > > --
> > > Jim Sower
> > > Crossville, TN; Chapter 5
> > > Long-EZ N83RT, Velocity N4095T
> > >
> > >
> > >
> > > >> Homepage: http://www.flyrotary.com/
> > > >> Archive: http://lancaironline.net/lists/flyrotary/List.html
> >
> > >> Homepage: http://www.flyrotary.com/
> > >> Archive: http://lancaironline.net/lists/flyrotary/List.html
>
> --
> Jim Sower
> Crossville, TN; Chapter 5
> Long-EZ N83RT, Velocity N4095T
>
> >> Homepage: http://www.flyrotary.com/
> >> Archive: http://lancaironline.net/lists/flyrotary/List.html
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