How about the KR-1b, Virg On Tue, 02 May 2006 12:14:29 -0400 Ron Butterfield <rbutterfi...@mebtel.net> writes: > At 07:30 AM 5/2/06, you wrote: > >Hello all, > > > >Is anyone out there in KR land considering (or now building) a KR2 > > >that would meet the qualifications for LSA certification? I made a > > >search of the archives but there didn't seem to be a lot there as > >far as LSA and KRs go. > > <originally posted 3/10/06> > After today's spate of LSA discussion, I put together a quick > spreadsheet to calculate various performance parameters based on the > > discussion and formulae on this page: > http://zenithair.com/kit-data/ht-86-8.html > > The straight Excel version is at: > http://home.mebtel.net/~rbutterfield/KR/Stall_speed_&_performance_calcula tor.xls > > If you (or your isp) have problems with spreadsheets, the same file > > compressed with WinZip is at: > http://home.mebtel.net/~rbutterfield/KR/sspc.zip > > I have entered CLmax from the stated sources for the two wings under > > discussion, but you can change that for other wings if desired. > > Constructive criticism welcome. > > And remember, it's worth what you paid for it (or maybe less ;-) ) > > I have NOT personally confirmed ANY of the data or formula in the > spreadsheet, so use it at your own risk. > <end old post> > > Top speed can be easily artificially limited by placarding a reduced > > max continuous rpm. > > Stall speed is the hard part. LSA requires the maximum stall speed > to > occur at gross, without the use of "lift enhancing devices", ie > flaps. Wing area and weight play a big part, but Cl even more so. > Good hard data seems a bit hard to come by, especially at the lower > > Reynolds numbers a KR flies at near stall. > > An interesting page of airfoil information is here: > http://www.oriontechnologies.net/Documents/Airfoil.htm > > I personally have settled (for now, anyway) on a KR1 with 72 sf of > 23015 tapered to 23012. With an estimated Cl of 1.6, that gives me a > > stall of 50.4 at a gross of 750. The spars and attachment of the KR2 > > are the same section, just longer, so it should be well within > limitations without re-engineering. > > For a KR2S and the new airfoil, the numbers get so far out of hand > that the spars and attach fittings would need to be completely > re-engineered. At a gross of 980, with Cl of 1.28, you need 111 sf > to > get a stall of 52. > > > > Regards, > RonB > > "expert riders use expert judgement to avoid using expert skills" > Phill Ross > > > _______________________________________ > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > >
Virgil N. Salisbury - AMSOIL www.lubedealer.com/salisbury Miami ,Fl
