Hi Again,
I stumbled to this when checking out newest avweb newsletter:
http://cafefoundation.org/v2/pav_pavchallenge_studies.php
They have a design competition - and for all the right reasons. They try
to press the costs of flying down.
Check out those pdf's, there's some very sensible points and neat design
innovations. Eg. concept of FAA-certified stock auto engine! No rotary
insights there, but that's excusable. Definitely worth reading.
Cheers,
Petri
Engineering student
Helsinki, Finland
btw. on holiday now, i'll get back to that hi-power rotary thing next week.
CAFE is OK but these NASA people don't have a clue. They are advocating
a 3900 pound, four place airplane powered by a 300 Hour TBO Chev V8 shaft driven
ducted fan. Obviously they are aviation history challenged.
Perry Mick
http://www.bridgingworlds.com/duckt.htm
gave it an excellent try for a lot of years and wound up installing a gear box
and prop and went 20 kts faster for the same fuel burn. If I were the CAFE
and EAA people I would disassociate myself from NASA as it is ruining the CAFE's
credibility. Dozens of ducted fans have been built over the last 50
years with the same bad results. Kuchemann and Weber identified the problem
in their book Aerodynamics of Propulsion published in 1953 page 134.
A new Chev V8 project shows up at OSH every year for the past 20 years
and it is gone in a year or two. They self destruct after a few hundred hours.
A whole lot of people dumped 50 million dollars U.S. into the Orenda big block Chev project
over a 30 year period and wound up going bankrupt or out of business. They changed every
part except the bore spacing and V configuration. What they should have done was design
and build a horizontal opposed version from scratch. V engine are heavy because they
are trying to force the crank into the oil pan.
A company in Midland Texas called Trace
http://www.traceengines.com/ bought what was left.
The 500 HP continuous... 600 HP take off engine weighs 750 pounds and they are
asking is $250,000 dollars U.S.. For that kind of money you can get
a PT6. Hope springs eternal.
In the mean time Dave Atkins has flown his Mazda rotary powered RV6 from Seattle to OSH
for the last 13 years straight. Tracy Crook's record is almost as good from Bell Florida to
OSH except for this year. I see Chuck Dunlap in his rotary powered RV6 from Arizona at
Sun n Fun and OSH almost every year. Other Mazda rotaries in aircraft have hundreds of hours.
Problems are never the engine. This year a four place two rotor powered Velocity
went 205 MPH in the Dayton to OSH race burning only 12 gallons an hour.
It would be nice if the CAFE foundation and NASA helped out the rotary community by
developing the turbo compound rotary engine.
http://www.scanlab.fi/docs/docs_index.htm
NASA_1994029727.pdf
http://www.rotaryeng.net/turbo.html
How about it Brien Seeley and Paul MacCready?
Paul Lamar
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