|
|
Flutter is intuitively an IAS issue, but TAS influences the harmonic aspects of the thing.
kenpowell@comcast.net wrote:
Hi Dave (and welcome John),
I agree that this (TAS) is really strange and not intuitive. But consider the source - Van himself!!! When I read this in RVator I had doubts but I gotta go with John on this unless we hear from another impeccable source to the contray. TAS it is!!!! Call Van if you need more info; I doubt any of us (do we have any aeronautical engineers on the list? I know we have every other flavor of engineer here!) have the knowledge to debate this with Van.
--
Ken Powell
Bryant, Arkansas
501-847-4721
-------------- Original message --------------
rv-7a wrote:
However, my bubble was busted by the Van's RVAtor article on
flutter (6th issue 2004). Van’s engineers instructed their
readership on flutter – that Vne is really a TAS limit, not an
IAS limit. A US Air Force pilot and RV commuter corroborated the
Van’s article by telling his disturbing TAS flutter story (first
2005 RVAtor issue). If you haven’t read this, I recommend it for
all pilots, no matter what they fly.
I’ve decided to follow Van’s advice and restrict my upper
airspeed to limit to 200 KTS TAS in smooth air. I don’t want to
be a test pilot. Therefore, I’m reconsidering my plan to
supercharge the Renesis/RD-1C installation. The weight penalty
may not be worth climb performance increase if 200 KTS TAS cruise
can be easily achieved with a normally aspirated installation. If
I can collect empirical data from RV Rotary flyers, it would sure
help my decision.
Thanks,
John Burns
rv-7a@comcast.net <mailto:rv-7a@comcast.net>
http://mywebpages.comcast.net/jgburns/Engine/Engine.html for my
engine webpage.
Intuitively it does not make sense that flutter is a TAS issue. I
would be interested in reviewing the engineering/hypothesis on
which this is based. The plane "feels" IAS.. not TAS... you can
have a TAS of 400 and still have only an IAS of 200 (if you are
high enough).. IAS is the dynamic pressure and state that the
aircraft experiences. So.. I would be greatly interested in
knowing why the engineers are making this claim and what its basis is.
Dave
Homepage: http://www.flyrotary.com/
Archive: http://lancaironline.net/lists/flyrotary/List.html
|
|