Deskpilot Posted January 23, 2010 Posted January 23, 2010 I heard about it a few years ago but have never been able to found any info on it, until now. Based on the Dyke Delta, a home build, 4 seat, tube and fiberglass, double delta cruiser, this is the single seat DYKE STINGRAY. Built by the Lowell Brothers, it is a 2/3 scale version of the original. Built of WOOD and fiberglass, and powered by a 100hp Continental, it cruised at 170mph (roughly 150knots). Flown for 30 years, it has now been retired to a museum. Unfortunately, no plans or other details are known, but I'm still searching. It's only drawback for us would-be builders is that it's landing speed was about 60 knots, so, what can be done to lower it. I've thought of adding VG's and flaps but that also neccesitates the addition of a small all-flying tailplane as fitted to some later Deltas. Do trailing edge flaps work at all on a delta? Leading edge 'flaps' are used on supersonic designs and might be worth looking at. Any other ideas guys? For the uneducated, a delta wing doesn't stall but wallows when too slow and rapidly loses height. Angle of Attack is somewhat critical so approaches have to made very carefully. Just re-studied the photo and see that the tailplane has been added.
Deskpilot Posted January 26, 2010 Author Posted January 26, 2010 I am so surprised, and some what dissappointed, that there are no comments on my previous post. Surely some-one has an opinion or other input.
turboplanner Posted January 26, 2010 Posted January 26, 2010 Go to an RC field and you'll see unconventional wings, and their characteristics. I had the feeling with this shape that pitch could be very sudden
pudestcon Posted January 26, 2010 Posted January 26, 2010 Sorry Deskpilot, Delta wings leave me cold from a recreation aviation (ultralight) perspective and I have no interest. From an RC perspective I reckon they are great fun for hotdogging around the sky cutting streamers and the like. Sorry this is not adding to the discussion you had hoped for but maybe others think the same as me. I do look forward to any further discussion though because there is always something to learn. Cheers, Pud
tangocharlie123 Posted January 26, 2010 Posted January 26, 2010 Hi Desk pilot EAA - EAA Experimenter - A Day with John Dyke and the Delta Flyers here is an article by the designer it may help have you joined the delta dyke forum they may have the answers.
dunlopdangler Posted January 26, 2010 Posted January 26, 2010 looks like it needs a canard out front:big_grin::big_grin:
Guest skyspud Posted January 26, 2010 Posted January 26, 2010 Reducing weight if possible might help lower your landing speed. Depends on what materials you can substitute,(perhaps fabric wings)? Continental engine (HEAVY) but they didn't have lighter choices 30 years ago! Winglets might help to control lift/drag at lower speeds? or lengthening wings to grab more air at lower speeds? I'll mill a bit more over it. skyspud Go fast and take chances
Deskpilot Posted January 26, 2010 Author Posted January 26, 2010 Hey TC123, hadn't seen that one before. Cheers but I have joined the Delta builders forum and have received a lot more info from them and the guys at HomeBuiltAirplanes.com - Experimental Aircraft Discussion Skypud, as I understand it, the wings started off as fabric covered but went to fiberglass for more strength. I want/would build in wood and f/g if I get that far. Keep em comin' guys. I'll see if I can produce a drawing of what I envisuage. DD Canards are only good for one thing, spoiling the view. Sorry but they do nothing for me. Always seem to be at the wrong end of the plane.
Skykid Posted January 30, 2010 Posted January 30, 2010 What changing the airfoil of the wing a bit? It'll take some of the speed away but will lower the landing speed. I agree with skyspud in using a lighter egine to. Is there much info about this aircraft or are you just using photos and limited repeated on every web sight you look on info for your research?
Guest skyspud Posted January 30, 2010 Posted January 30, 2010 G'day again Deskpilot, Another idea, on the air tractors I drive the ailerons come down a certain factor proportionate to the angle of flap applied. Like flapperons but not with as much of an angle of deflection. This will help give more even lift off the whole wing and not just near the root. Maybe important given how short the wings are on the Dyke Delta. If not much can be done to change the landing speed, maybe some kind of spoiler can be projected into the airflow after landing to increase deceleration? skyspud Go fast and take chances
Deskpilot Posted January 30, 2010 Author Posted January 30, 2010 Hi guy, thanks for your time and your thoughts. I just re-read my posts and realize that I made a mistake in the first one. It's not the landing speed I need to lower, it's the stall speed, not that a delta stalls as such. It begins to wallow and loses height very quickly. The latest modifications in the U.S. have it landing at 60 mph (approx 53 knots), a lot slower than a Jab, but that is just above it's stall as I understand it. A lighter build using honeycomb panels is one way to go (haven't looked at cost yet) and/or a lengthening of the wing cord, easy to do but got to delve deeper into C.G./C.L. positions etc. The current wings are symetrical in profile, a shape that baffles me somewhat. How can it produce lift when top and bottom are equal and opposite? Got to do some research there as well. Perhaps a flat bottom aka the Facetmobile might work although something twix the 2 is more probable. Lots of work to do. BTW, I've located the builder of the Stingray in Mt Vernon, Ohio. Now I need his e-mail address. Looks like I've got to spend the bucks and phone him (I'm such a tight-a*se)
Skykid Posted January 31, 2010 Posted January 31, 2010 What about having a concave strip near the leading edge of the wing? From what I remember being told in lowers the stall speed and gives a better handling at lower airspeeds. From memory the C-172M modle has them.
Deskpilot Posted January 31, 2010 Author Posted January 31, 2010 I'm guessing that would act like a full width V.G. I'll look into it, Thanks.
Deskpilot Posted February 1, 2010 Author Posted February 1, 2010 It's been another of those slow days so I've been doodling with Sketchpad. Just image it with nice curves intead of flat planes, except for the body top. Thats a lifting surface so will be flat, The intention it to have an unrestricted run from front to back, hence raised tail assy. Doable?
turboplanner Posted February 1, 2010 Posted February 1, 2010 High class drawing Doug, you a professional? Took a look at the facetmobile, and noticed it flew distinctly tail down (but still had good cruise speeds). It was described as a "lifting body", less wing area than yours, but to me it looks as if most of the lift is pressure on the under surface (not much Bernoulli.) I also notice a lot of talk about sweep back and vortex, so I assume these wing shapes usually go well with compressible situations. Honeycomb construction is not expensive, but the honeycomb material is normally available in constant width, so may not suit your shape. On the other hand your shape is almost perfect for a triangulated space frame - easy for an engineer to do stress calculations too. I just took some time out to spend flying a Slinger RC on the simulator - shown on this site. Great Planes Slinger Flying Wing ARTF c/w Motor (GPMA1180) | Antics Online The wing design is quite different, being much longer and narrower. At less than half throttle, where RC models start to mimic the real thing, the roll was very gentle, and it didn't want to stall at all, but you had to be on it every inch of the way to avoid a sharp downward pitch. It never pitched up, just down. Back stick got it out every time, but it almost whipped down, and that would be an issue close to the ground. Your wing may produce different handling, but I thought it was worth mentioning.
Deskpilot Posted February 1, 2010 Author Posted February 1, 2010 Hi TP, no not professional. Actually it's not a drawing. Google-Sketchup is a 3D modelling program (free to download) and this is just a 2D image off the screen. I had a look at your Slinger. A totally different concept in that it is a Flying Wing with a pusher prop. I would expect the handle characteristics to be totally different also. My design is a Double Delta and it flies some-what flatter than the Facetmobile.
Deskpilot Posted February 1, 2010 Author Posted February 1, 2010 Ooops, seen my mistake that might have confused TP. It's Sketchup, not Sketchpad. Sorry. I really must actually read my posts and see what I have written instead of what I think I've written. BTW TP, Take a look at my other post 'What the future holds' It's a full description of the latest Facetmobile and describes how it uses flat panels. At this stage, I do not intend to use flat surfaces on the wings. It was just easier and quicker to model that way.
Deskpilot Posted February 11, 2010 Author Posted February 11, 2010 For further posts on this subject, please go to my new thread 'Introducing the EagleRay' where a more realistic model has been introduced.
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