Remi, The comparisons I did between low & high twist woodcomp props were
rigorous, all early in the day and over water to eliminate the risk of
catching an early thermal. They were also all done approaching the test
conditions from above, that is doing a shallow dive from something like
100ft above the chosen altitude and then waiting for the speed to
stabilise whilst flying level. They showed a clear 5 kt advantage at low
& middle altitudes (Vne exceedable at 10,000ft so no comparison
possible) but also a clear cooling advantage not just on the ground but
in the air. The required 5 min full power climb boiled the engine with
the low twist one but was achieved without incident with the high twist.
It is worth restating that with twist of the order of 14 degrees either
the tip will be stalled or the inner part of the prop will be in Beta
mode at speeds of 100kts or more. Ask yourselves why all prop driven war
birds or Red Bull racers and the like have props with 24 or 26 degrees
of twist!
Regards, David Joyce, GXSDJ
On 2017-05-14 14:30, Remi Guerner wrote:
>
> Jim,
> 14 degrees of twist for the Whirlwind! By comparison, the WarpDrive blade has
16 degrees of twist and the high twist Woodcomp 24 degrees. So should we ask
Whirlwind to design a new blade with more twist ? That would at least improve
ground cooling and possibly give us some more speed.
> Remi Guerner
> F-PGKL
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=469296#469296 [1]
>
Links:
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[2] http://www.matronics.com/Navigator?Europa-List
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[4] http://wiki.matronics.com
[5] http://www.matronics.com/contribution
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