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Hi Chad,
Actually, I intended to see if the "adjustable" length manifold would
provide benefits worth the investment in time and effort. The theory
indicates I should be able to adjust it to provide additional power for take
off and for cruise. Actually, in cruise it would enhance volumetric
efficiency (if it works as I hope of course).
There are two variables (pulse duration and manifold air temperature) in the
EDDIE equations that I do not have empirical data for which can skew the
curve one way of the other. Since I don't want to get involved in a lot of
instrumentation, time and money to try to determine the values, I hope to
get a handle on them empirically by test flights and correlating OAT, RPM
and Altitude to narrow down the possible range of these values. If I can
correlate OAT with the effect then I can nail dow manifold air temperature,
making it possible ( I believe) to get a better handle on the remaining
pulse duration variable in the equation.
Regarding your question - IF this experiment works out to increase
torque/power as the theory indicates and I am able to narrow the values of
variables, then one indeed could elect to fabricate a fixed length manifold
for a desired rpm such as take off/climb or cruise. However, unless the
mechanism I used to vary the length causes problems or is unreliable, I
would probably fly maintaining the variable feature. It really depends on
whether it shows benefit. It might show that power gain is meaningful for
take off but the effect fades at higher rpm or vice versa. In which case, a
fixed length would be the logical thing to do.
If I do not gain at least 15 HP then the variable feature is probably not
worth the hassle in my opinion. So stay tuned, as usual I will report the
good, the bad, and the ugly.
Ed
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message ----- From: "Chad Robinson" <crobinson@rfgonline.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Thursday, April 15, 2004 9:34 PM
Subject: [FlyRotary] Re: FW: Ed's adjustable intake?
Jack Beale wrote:
>
> Yes, he did...! I spoke to him for quite awhile on Wednesday
> afternoon; and, while there, Ed demonstrated his 'adjustable intake'.
> Pretty impressive engineering job. I believe the jury is still out on
> the benefits...
I don't remember the original point. Did Ed intend to make this a
permanent
modification, or to gather performance data for a later, permanent
decision
with a fixed-length intake?
Regards,
Chad
>> Homepage: http://www.flyrotary.com/
>> Archive: http://lancaironline.net/lists/flyrotary/List.html
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