A.A. Barry Posted April 26, 2009 Share Posted April 26, 2009 This so ugly, that someone should love it, the calculations have been done, 1064 mm W/span, Twin ep powered canard. One of Kurt Tanks also ran aircraft, bits from a few other aircraft, so here is the challenge, WE will find out as things progress. got to uderstand how to "post pic' on this new site. Barry Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted April 26, 2009 Share Posted April 26, 2009 Barry, as stated several times there is a tutorial on posting poictures - it is actually easy. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted April 26, 2009 Author Share Posted April 26, 2009 Ta Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted April 27, 2009 Author Share Posted April 27, 2009 Thanks to Tony R for the pic Quote Link to comment Share on other sites More sharing options...
Ernie Posted April 27, 2009 Share Posted April 27, 2009 Hi Barry, Have you calculated the balance point? ernie Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted April 27, 2009 Author Share Posted April 27, 2009 Ernie, yes i have done some of the sums, one of the guys sent me a site to calculate C/G, given all the par's, and as yet all dimensions are appox and not fixed , yet. It looks like to be just backward of the wing L/E, thanks. Barry Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted April 27, 2009 Share Posted April 27, 2009 Hi Barry If the CofG is just backward of the L/E what about the directional stability? i.e the moment of the side area ahead of the CofG compared to that behind. Looks all wrong to me. There was no doubt Kurt Tank was a brilliant designer but I would be amazed if you could ever keep this in controlled flight unless you had some very clever electronics to help. I would build a simple chuck glider first to get some idea of its flight characterisitics. Quote Link to comment Share on other sites More sharing options...
Ernie Posted April 27, 2009 Share Posted April 27, 2009 Hi Barry, Have you got a scale drawing that you can post? I'd love to knock up a chuckie for you, and check it out..You never know, you might get dozens of wee canard prototypes ernie Quote Link to comment Share on other sites More sharing options...
Terence Lynock Posted April 27, 2009 Share Posted April 27, 2009 Hi Folks, thought these may be of interest; regards, Terry Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted April 28, 2009 Author Share Posted April 28, 2009 Ernie, yep, that will be interesting, (chuckies) the only drawings are above, that Terry L posted, Ta Terry Simon, I don't know, other than build one and see what happens, bin bags are still handy. Now I have to clean of the "bits and pieces" (err... Dave Clarke 5 ) from the model table and set to and get this drawing done....... Barry Quote Link to comment Share on other sites More sharing options...
Ernie Posted April 28, 2009 Share Posted April 28, 2009 Hi Barry, I made this at twice the size of the 3 view that you sent (It's 35cm span) Initial test flights (across the bedroom) show a balance point of just in front of the leading edge. Tomorrow, if the rain stops, I'll embark on a comprehensive flight testing I've set the wing at around + 2 incidence ernie Quote Link to comment Share on other sites More sharing options...
Chris C Posted April 29, 2009 Share Posted April 29, 2009 that thing flew! wow does that mean anything will fly?? Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted April 29, 2009 Author Share Posted April 29, 2009 WEll Ernie, it does look like it will fly, 2 deg incidence is interesting, have to wait till your next report thanks, Barry so it seems everything that is red is not always a rose Edited By Barry Wetherell on 29/04/2009 11:58:56 Edited By Barry Wetherell on 29/04/2009 12:00:42 Quote Link to comment Share on other sites More sharing options...
kiwi g Posted May 11, 2009 Share Posted May 11, 2009 barry . I see some talk of incidence and cog. I have a model long ez (chinese made) a couple of friends had them too but thiers would not fly properly. we saw that the canard had -2 to 0 of incidence.( yes they were all different) I set mine up with 2+ incidence in the canard with the wing set at zero. The cog is 65 mm back from the leading edge (its a swept wing). Point being in relation to a constant chord wing the COG would be as you say just behind leading edge. I would suspect aprox 1/8- 1/4 of the chord. The long ez is electric with a het 600 pusher 4 cell and is the sweetest thing to see fly. all the others needed lots of speed and suffered from terrible spins. mine is happy to fly all day everyday. hope this helps. Cheers kiwi G Quote Link to comment Share on other sites More sharing options...
Ernie Posted May 11, 2009 Share Posted May 11, 2009 Hi guys, Graham, I'll try the wee model as you describe. ernie Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 11, 2009 Author Share Posted May 11, 2009 Ernie did the glider fly, at what you thought??? TA Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 11, 2009 Author Share Posted May 11, 2009 G.A Kiwi, when I did the C/G check, as per the web site, It did work out to be behind the L/E of the canard, all things considered, that is correct. Good stuff........Barry Quote Link to comment Share on other sites More sharing options...
Ernie Posted May 11, 2009 Share Posted May 11, 2009 Hi Barry, It did sort off, but not very well. I'll try it at 2deg positive on the canard, and the CG back from the LE ernie Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 11, 2009 Author Share Posted May 11, 2009 Thanks Ernie, "the world is waiting" B Quote Link to comment Share on other sites More sharing options...
Ernie Posted May 11, 2009 Share Posted May 11, 2009 Hi Barry, I'm afraid the world will have to wait a wee while, we have a tempest here, and we don't want it all soggy, do we? ernie Quote Link to comment Share on other sites More sharing options...
Ernie Posted May 11, 2009 Share Posted May 11, 2009 HI world Le tempete has vanished over the Medoc So far, its a wee piggy, flies better backwards than forward. Maybe I'll build a bigger one, so that I can be a bit more accurate. Please, you aerodynamicists, give me some more imput.. What about wing section, tailplane area, moment arms etc ernie Quote Link to comment Share on other sites More sharing options...
kiwi g Posted May 12, 2009 Share Posted May 12, 2009 barry did you mean CoG just behind leading edge of wing . or did it work out as you say on the canard ???? I studied this topic a bit when we were getting long ez going. We found lots of inconsistant information .There are alot of theories behind the canard aircraft and its stall properties.The best I can offer is the canard flies first and treat the main wing as something thats hanging off the back. the canard flies slightly nose up so gives the impression of needing a neg incidence ,but in my case I found it not so. I hope this helps. Kiwi G Quote Link to comment Share on other sites More sharing options...
Erfolg Posted May 12, 2009 Share Posted May 12, 2009 From my own limited experience. The fore wing has to carry by proportion a greater proportion of the weight. To achieve this, the fore wing will be at a greater angle of attack relative to the aft wing. Otherwise it would not be in equilibrium under static flying conditions. Being at a greater angle of attack, when the system is brought to a stall, the foreplane will stall first. The only real problem that I found, if the same section is used on the foreplane, relative to the aft wing, it will stall quite early. As the reynold numbers are not as favorable due to the smaller chord. In other words the fore plane is not as effective as the rear plane. I therfore increased the camber on my foreplane. In all honesty it did not seem to make much difference. Contary to theory, my canrd did not have a benign stall, the foreplane would stall and the nose would drop. I tried many solutions, rounding the leading edge of the foreplane more, tapering the leading edge. Moving the CG, further aft, moving it forword. As the foreplane was all flying this was no problem. It still behaved much the same. As it was supposed to be a competion sailplane for the flying wing section of the BARCS 100s leauge, it was abandoned, as it was uncompetative, and not as predictable as required. It was never entered into any comp. All I can realy say it flew, it was no great revalation. It was just not worth the effort to try and improve it, flying wings (planks) were better, in all respects and conventional sailplanes were in a different leauge. The difference between Manchester United and Accrington Stanley. Erfolg Quote Link to comment Share on other sites More sharing options...
Ernie Posted May 14, 2009 Share Posted May 14, 2009 Hi Guys, I've built a bigger chuckie (2ft span) so that I can be more accurate..It's still a piggie. I just can't get it right at 2 deg positive on the canard. Surely the main plane needs to be positive to give some lift. Help you aerodynamanuts ernie Quote Link to comment Share on other sites More sharing options...
kiwi g Posted May 14, 2009 Share Posted May 14, 2009 Ernie sorry to here its not working. Question. Is it undulating in flight. porposing. Quote Link to comment Share on other sites More sharing options...
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