Former Member Posted February 20, 2018 Author Share Posted February 20, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Caveman Posted February 20, 2018 Share Posted February 20, 2018 David, no mystery about the pronunciation of Leonhard Euler's name. He was born in the German speaking part of Switzerland, and in the German language 'eu' is pronounced 'oy', hence his name sounds like 'oyler'. Cheers GDB Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 20, 2018 Author Share Posted February 20, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Jez Saunders Posted February 20, 2018 Share Posted February 20, 2018 David, you obviously understand the subject of aerodynamics well , I follow some of what you say and have gained a little more understanding of the subject. Thank you. I don't think you are" being clever " . Discussion and debate are an essential part of learning. There should be no such thing as a stupid question and that should be a strength of this forum ( and other's ) difference of opinion is what leeds to ideas and understanding. There should be more debate like this, I am no intellectual but I do enjoy this type of discussion and it should be encouraged !😃 Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 20, 2018 Author Share Posted February 20, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
eflightray Posted February 20, 2018 Share Posted February 20, 2018 A Google search on --- rc rule of thumb plane dimension **LINK** There is plenty of information people put online, it's a case of trying a few variations on the question. Another handy one is using the Google Image search. If you're looking for plans, try --- rc plane plans, if you just want to get some ideas, or even name the model you are looking for, e.g. --- rc spitfire plans. The web is full of plans usually free to download. But PLEASE, don't ask questions about 'lift', just accept it happens. Ray. Quote Link to comment Share on other sites More sharing options...
Jez Saunders Posted February 20, 2018 Share Posted February 20, 2018 I was wondering if the Wright brothers used for formula in their creation of the Wright flier ? Some time later, a few decades, R J Mitchell designed the Spitfire who would certainly have used it, the Spitfire is aesthetically pleasing to the eye , but I read somewhere that the wing cord was a thick as it was because the at the time of design glycol had not been invented and the wings were to condense steam from the heat of the engine for cooling, some of its flight performance potential was luck, also it looked right so it had to work ! Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 20, 2018 Author Share Posted February 20, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
eflightray Posted February 20, 2018 Share Posted February 20, 2018 But then we build and fly toy planes, and can get almost anything to fly these days. With or without an in depth knowledge of aerodynamics. But if people want to learn all the technical side of aerodynamics, (most, if not all will be for full size aircraft), go for it. Ray. Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 20, 2018 Author Share Posted February 20, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Jez Saunders Posted February 20, 2018 Share Posted February 20, 2018 And a model size aircraft probably is easier to get into a flying condition than a full size aircraft, Reynolds effect etc. Maybe ? Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 20, 2018 Share Posted February 20, 2018 Posted by Jez Saunders on 20/02/2018 21:19:54: And a model size aircraft probably is easier to get into a flying condition than a full size aircraft, Reynolds effect etc. Maybe ? For sure Jez A full size laden Spitfire weighs approx 6000lb An RC 1/6th scale Spitfire, weighs about 12lb, and the arithmetic would put it at 1000lb Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 21, 2018 Share Posted February 21, 2018 Denis 1000 lbs? I think you are ignoring the cube rule. For the same material 1/2 the size = 1/8 the weight. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 21, 2018 Share Posted February 21, 2018 Posted by Simon Chaddock on 21/02/2018 00:11:14: Denis 1000 lbs? I think you are ignoring the cube rule. For the same material 1/2 the size = 1/8 the weight. Thanks bud, when I started to think about it with the model built from balsa and the full size built from derivatives of aluminium And then the Merlin engine, then I just ducked out, as a1/6th scale replica, approx 6 foot wingspan, would come out weighing 100s of lbs, being too silly to consider. Edited By Denis Watkins on 21/02/2018 07:40:56 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted February 21, 2018 Share Posted February 21, 2018 6000 / (6 x 6 x 6) = 27lbs A factor of 2 or 3 larger than what you'd hope for in a model. Which is actually not so very far out - the basic operation of 'divide by the cube' ignores any Reynolds type effect on the aerodynamics. In model sizes the structure also doesn't need to be as strong - think flea jump vs the elephant jump type effect - and we carry practically no payload, little fuel and no pilot. Similarly, I've found the wing cubic loading calculations at model size come out around half (lightplane) or third (warbird) of what they come out for a full size. Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 21, 2018 Author Share Posted February 21, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 21, 2018 Author Share Posted February 21, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted February 21, 2018 Share Posted February 21, 2018 I have read most of the posts on this thread and very learned and scientific they are but I was reminded of something that happened in the late 50s. The officer in charge of St Mawgan's model club was Noel Falconer and he designed a control line stunter. called Gaisgeach (Warrior), To quote his text from when the plan came out in Model Aircraft: The initial design was very highbrow. It came from structural and Aerodynamic study (I believe his subject at university) plus a mathematical study of existing designs. The model went through 4 separate versions. I can say that I had one of Noel's and it was a superb model, I admit that with my limited aerobatic skills I could not do justice to such a refined model. Well what would you expect from a model with such a pedigree. Then one day Noel needed a stuntcr in a hurry, I think his models were at home and he had no time to get home and collect one so he knocked up a very basic stunter. Box fuselage, parallel chord plank wing, similar all sheet tail.Wing section TLAR. Much to Noel's disgust he admitted that it flew far better than his highly researched highly developed model. There is a lesson there. Don't knock the TLAR method of designing Edited By Peter Miller on 21/02/2018 11:26:32 Quote Link to comment Share on other sites More sharing options...
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Denis Watkins Posted February 21, 2018 Share Posted February 21, 2018 Thanks for all your efforts Dave, very useful to have it laid out properly. A very thought provoking thread. The OP suspected there were some form of rules Maybe guidelines were another choice for the title All useful stuff from all of you Quote Link to comment Share on other sites More sharing options...
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The Wright Stuff Posted February 21, 2018 Share Posted February 21, 2018 Posted by David Mellor on 21/02/2018 12:39:27: What TLAR tells us is that good RC models of Spitfires have around half the value of the real (full sized) plane's cubic wing loading. .. it is actually accurate over a range of different wingspans of interest to model designers. I'm a little wary of dividing aircraft into 'full size' and 'models', and then saying it applies to a range of wingspans. Surely the 'half the value' must be a continuous function of wingspan, otherwise how do you reconcile the value calculated for a 99% size scale model. TWS Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 21, 2018 Author Share Posted February 21, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 21, 2018 Author Share Posted February 21, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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