Message-ID: <004d01c3a677$8b20af80$1702a8c0@WorkGroup>
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-2715556@logan.com>
Subject: Re: [FlyRotary] DIE Effect
Date: Sat, 8 Nov 2003 23:11:25 -0500
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Subject: [FlyRotary] DIE Effect


> Good Evening...
>
> Is the DIE effect simply the same intake tuning method
> which folks have been using for years?  Except in the
> case of the 2 rotor engine we do not have to play the
> whole positive pressure wave/negative expansion wave
> game as the positive pressure wave can be used
> directly by the opposing rotor.  Hence, the need not
> to vary the width( by much ) of the intake pipe less
> you create a negative expansion wave heading towards
> the originating rotor.
>
> -Scott
>
> =====
> Thank You.
>
Nothing new under the Sun as they saying goes.

Yes, to answer your question, Scott.  There are two types of intake tuning
as best I can determine,  there is tuning for inertia effect whereby you
design the manifold to certain lengths that promote better airflow at
certain rpms generally keeping the intake velocity (and inertia) high.  This
tends to "stuff" more air into the chambers when the ports are open>

Then there is "Pulse tuning" which relies on the characteristics of
finite-amplitude-waves which is a pulse of energy traveling at the speed of
sound in the manifold.  Proper configuration and timing transforms this
kinetic energy into localized manifold pressure near an intake port and may
either "push" more air/fuel mixture into the chamber or may overcome
"reversions" - perhaps both.

In reality, some of both probably happens when people do intake tuning.
Many times however, the results is less than predictable due to the number
of variables involved and lack of knowledge about which effect my be
producing which results.

The DIE effect is referring to the latter "Pulse Tuning" method.  Yes, the
unique configuration of the twin rotor makes using the pulse tuning method
more effective than on reciprocating engines.  The DIE effect does rely on a
Positive Pulse and since this pulse activity is exchanged between the intake
ports of the two different rotors, the timing is simpler and effectiveness
is greater than trying the very difficult timing task of trying to
synchronize pulses for a multiport, multicylinder reciprocating engine..

Ed Anderson