Date: Friday, May 11 2007 02:29 pm From: Graham Singleton To: europa-list@matronics.com, ptiller@lolacars.com, fklein@orcasonline.com Reply-To: europa-list@matronics.com Subject: Re: Europa-List: Votex Generators Attachments: Part 1: noname (TEXT/PLAIN 7bit 2949 bytes) Part 2: Ted Gladstones wing root em.jpg (IMAGE/JPEG base64 290326 bytes) Phil the nioest wing root I've seen is Ted and Justin's, small radius at the LE, large at the TE. picture attached. imho this is the way to do it, the fillet needs to be flexible to allow wing bending without crushing the fuselage side, so no more than 3 plies of BID at the edge. There are several Europas with this style but only Ted's has the elegant change of radius moving aft. Easier to rig a wing done like this too, something to line up with as it goes in. Graham flyingphil2 wrote: > --> Europa-List message posted by: "flyingphil2" > > Hi Fred, > > Well my thoughts on this would be as follows: > > 1. Is there a problem in that area? Oil flow tests would show up any separations in that area or maybe someone with a dirty aircraft has flown through rain and has some pictures of the surface flow patterns that were left. If there is no obvious problem then I'd leave it alone. > > 2. If there is a problem then making a really good job of the wing fillets would be the best approach and maybe trying to maximise the radius of that fillet (larger radius = better). The problem with a large radius is what happens when you come to the trailing edge of the wing (or in the Europa's case, where the wing ends and the flap starts). You need to lose that large radius and run it out to nothing smoothly. > > 3. Sealing the wing against the fuselage would definitely be good. On gliders, we use PVC tape but that only works if you have a small 'wing stub' moulded into the fuselage that the wing butts up to. On a Europa I would say that some high density foam on the inside of the wing root fillet would do the trick and when the wings are fitted, the foam is compressed and thus forms a nice seal. I.m not sure what gaps people have between the fuselage and the wing fillets but try and keep them as small as possible. > > In terms of drag reduction I would have thought that there is little to do on the Europa. It's already an excellent design and the use of composite materials (and ability to build almost any shape) helps this. Compared to some homebuilts on the market using the same engine, it has to be a very efficient machine. Having said that, you notice the difference on a glider if the wing roots are not taped and the controls are not sealed and so all these little bits of attention to detail would add up and help reduce the drag that little bit further. > > Actually, that's an interesting point above. Out of all the homebuilts powered with a 912S, there can't be many aircraft that are faster than a Europa. There is the DynAero MCR1 (which I had an amazing flight in once) and that is very fast but look at the size of it - it's tiny. Anyone have any other comparisons? > > Phil > > > > > > > Visit - www.EuropaOwners.org > > > > > > > > > -- Graham Singleton Tel: +441629820187 Mob: +447739582005