I’m suspicious of anyone who knows the second verse. -----Original Message----- From: "JR" <[EMAIL PROTECTED]> To: "Tom Wilksch" <[EMAIL PROTECTED]>, "Discussion of issues relating to Soaring in Australia." <[email protected]> Date: Tue, 20 Jun 2006 22:51:20 +0930 Subject: Re: [Aus-soaring] Bent up wing outer panels
Well he only lasted 2 minutes with me, if they cant sing the first line of advance australia fair I hang up ----- Original Message ----- From: "Tom Wilksch" <[EMAIL PROTECTED]> To: "Discussion of issues relating to Soaring in Australia." <[email protected]> Sent: Tuesday, June 20, 2006 10:30 PM Subject: Re: [Aus-soaring] Bent up wing outer panels > yes, they seem to take 10 minutes to get to the point > > ----- Original Message ----- > From: "Patching" <[EMAIL PROTECTED]> > To: "Discussion of issues relating to Soaring in Australia." > <[email protected]> > Sent: Tuesday, June 20, 2006 9:05 PM > Subject: Re: [Aus-soaring] Bent up wing outer panels > > > Oh yes inddeedy, they have a very interesting way of communicating. Fast? > I'm not too sure of that. > Ian P > ----- Original Message ----- > From: "JR" <[EMAIL PROTECTED]> > To: "Discussion of issues relating to Soaring in Australia." > <[email protected]> > Sent: Tuesday, June 20, 2006 6:15 PM > Subject: Re: [Aus-soaring] Bent up wing outer panels > > > > Ian, > > I spoke to the worlds fastest Indian on the phone last night, he was > > trying > > to convert me to another phone company > > regards JR > > ----- Original Message ----- > > From: "Patching" <[EMAIL PROTECTED]> > > To: "Discussion of issues relating to Soaring in Australia." > > <[email protected]> > > Sent: Tuesday, June 20, 2006 1:10 PM > > Subject: Re: [Aus-soaring] Bent up wing outer panels > > > > > >> Hey caleb, > >> the kookas' all have a decided wing kink as well. Just goes to proove > >> the > >> everything stays the same, it just gets refined a little. > >> See ya, I'm off to see the Worlds Fastest Indian. > >> IP > >> KPST > >> ----- Original Message ----- > >> From: "Caleb White" <[EMAIL PROTECTED]> > >> To: <[email protected]> > >> Sent: Tuesday, June 20, 2006 1:01 PM > >> Subject: Re: [Aus-soaring] Bent up wing outer panels > >> > >> > >> > Hi Folks, > >> > > >> > I think this discussion needs some clarification as to what is referred > > to > >> > as a ‘kink’. Are we referring the stepped taper (when viewed in plan > > form > >> > from above) as the ‘kinks’? In which case we are discussing the desire > > to > >> > achieve an elliptical plan form (with the intent of achieving an > >> > elliptical lift distribution) OR Are we discussing the stepped changes > > in > >> > dihedral in which case we are talking about achieving elliptical > > dihedral? > >> > > >> > As with all aircraft design the design of sailplane wings is a > > compromise. > >> > What is desirable is balanced with what is affordable to manufacture. A > >> > stepped planform and dihedral is an excellent example of ‘optimised > >> > compromise’. > >> > > >> > Cheers, > >> > > >> > Caleb > >> > > >> > Kookaburra Precision Soaring Team > >> > > >> > > >> > -----Original Message----- > >> > From: Mike Borgelt <[EMAIL PROTECTED]> > >> > To: "Discussion of issues relating to Soaring in Australia." > >> > <[email protected]> > >> > Date: Tue, 20 Jun 2006 12:46:06 +1000 > >> > Subject: Re: [Aus-soaring] Bent up wing outer panels > >> > > >> > At 11:57 AM 20/06/2006, you wrote: > >> >>Dear All (Bernard E would read this as 'space' but I'll stay with the > >> >>English) > >> >> > >> >>There is the limitation in two dimensional aerodynamics of a minimum > >> >>in the induced drag coefficient of: > >> >> > >> >> Cd (induced) = Cl squared divided by (Pi X Aspect > >> >> ratio). (Apologies, I haven't the time to write it out clearer.) > >> >> > >> >>So with an ideal lift distribution along the two dimensional wing > >> >>planform, that is the lowest you can get the induced drag > >> >>coefficient down to. Induced drag relates to drag due to wing tip > >> >>vortices (actually more complicated than just tip vortices but let > >> >>us leave that for now). > >> >> > >> >>I think somewhere I have in my overloaded filing cabinets an article > >> >>from a learned aerospace journal which deals with induced drag for > >> >>wings operating in three dimensions. My recollection (unchecked > >> >>because the article is somewhere misplaced) was that when the wing > >> >>was considered to operate in three dimensions, and computing power > >> >>was brought to bear on the calculations, a slender wing with the > >> >>outer sections bending upwards and backwards could achieve an > >> >>induced drag coefficient BELOW the minimum as determined from two > >> >>dimensional aerodynamics. > >> >> > >> >>I remember when the Nimbus 4 first came out and there was a photo of > >> >>the 25 m wings bending significantly upwards during steep > >> >>thermalling turning. So we have with our sailplanes with higher > >> >>aspect ratios and more slender spars wings which are operating in > >> >>three dimensions. > >> >> > >> >>So I do not think that wing kinks in the outer wing panels are a > >> >>fashion statement or a marketing ploy, but rather founded on serious > >> >>efforts to reduce drag. > >> >> > >> >>Beyond that I leave it to some far more knowledgeable person on wing > >> >>aerodynamics to provide futher illumination on the matter. > >> >> > >> >>Cheers > >> >> > >> >>Roger Druce > >> >> > >> >><mailto:[EMAIL PROTECTED]>[EMAIL PROTECTED] > >> >> > >> >> > >> > > >> > Roger, > >> > > >> > I think I have the same article by the late R.T.Jones of NACA and > >> > later NASA reknown. I guess the issue is - does the discontinuity at > >> > the kink increase the profile drag more than the 3D nature of the > >> > bent wing decreases it. > >> > > >> > The tendency at a kink is for the leading edge discontinuity to trip > >> > flow to turbulent and for the airfoil to stall earlier although it > >> > would seem you would need a fairly marked kink for this to occur. > >> > Allegedly this is what happened on the F4U Corsair(the earlier stall > >> > in the kink. > >> > > >> > Mike > >> > Borgelt Instruments - manufacturers of quality soaring instruments > >> > phone Int'l + 61 746 355784 > >> > fax Int'l + 61 746 358796 > >> > cellphone Int'l + 61 428 355784 > >> > Int'l + 61 429 355784 > >> > email: [EMAIL PROTECTED] > >> > website: www.borgeltinstruments.com > >> > > >> > _______________________________________________ > >> > Aus-soaring mailing list > >> > [email protected] > >> > To check or change subscription details, visit: > >> > http://lists.internode.on.net/mailman/listinfo/aus-soaring > >> > > >> > > >> > > >> > > >> > _______________________________________________ > >> > Aus-soaring mailing list > >> > [email protected] > >> > To check or change subscription details, visit: > >> > http://lists.internode.on.net/mailman/listinfo/aus-soaring > >> > > >> > > >> > -- > >> > No virus found in this incoming message. > >> > Checked by AVG Free Edition. > >> > Version: 7.1.394 / Virus Database: 268.9.1/369 - Release Date: > > 19/06/2006 > >> > > >> > > >> > >> _______________________________________________ > >> Aus-soaring mailing list > >> [email protected] > >> To check or change subscription details, visit: > >> http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > _______________________________________________ > > Aus-soaring mailing list > > [email protected] > > To check or change subscription details, visit: > > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > > > -- > > No virus found in this incoming message. > > Checked by AVG Free Edition. > > Version: 7.1.394 / Virus Database: 268.9.1/369 - Release Date: 19/06/2006 > > > > > > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.394 / Virus Database: 268.9.1/369 - Release Date: 19-06-2006 > > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.394 / Virus Database: 268.9.1/369 - Release Date: 19-06-2006 > > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
