![]() See how it does for meeting your requirements and goals. Create a template wing, using a single airfoil family, and get it somewhat optimized. Span limit? Weight limit? Powertrain options? Desired airspeeds? Control characteristics maneuvering characteristics? Then determine your limitations and expectations. Then enumerate your design goals - make a list. Then get some practice in with an analysis tool, such as XFLR5 or Profili, that can generate good results for low Reynolds numbers wings. One can design a wing and then find it to be completely unflyable by a mortal in real life atmospheric conditions.įirst study up a bit on how to read polars and various ways to analyze the data. Which suits you the best will depend on how fast you need to cover ground and under what sort of conditions it needs to be done and what you're going to use for power. There's no doubt that the focus has changed from low sink rate to best L/D and the ability to use this to cover a lot of ground in a short time in an efficient manner. ![]() Anything more than that seems to be seen as "floaters" these days. Modern competition sailplanes are even opting for airfoils with camber values from 1.5 to 2%. Your two options of symetrical or high camber are like the bear's porridges being superheated and at somewhere down near absolute zero. Just like the kid's story the best porridge is the one that is neither too hot nor too cold. You would be looking for an airfoil with good lift/drag figures.Įxactly. A slightly or moderately cambered airfoil (about 2 -4%) would likely be the best if distance is the objective. Haven't analysed the graphs Norm gave me yet, it may have the answer i will get back to that later.įor greatest distance you would want neither a symmetrical or a highly cambered airfoil. Will a symmetric or high cambered airfoil take me greater distance with same mAh? My question still would be what is the difference in efficiency and maneuverability. I already knew high cambered airfoil gives greater lift at 0 angle of incidence vs symmetric airfoil.Īnd so a symmetric airfoil needs to have a larger angle of incidence to allow the fuselage to be "flat" to the airflow in normal cruising flight. I will probably end up building more prototypes to get wing loading and airfoil type, i don't expect it to be perfect at first. I would like to get gliding distance >17. The goal is the best gliding efficiency, lowest drag, with a BLDC motor and LIthium batteries. And some healthy plagarism from those designs for your first efforts doesn't hurt either. Study the designs of others that have built successful models of the same type and try to learn why they picked and shaped the way they did. In the meantime take some time to learn on your own the same way that many of us did. Realistically you are not going to design and build a world beater on any of your first half dozen efforts. ![]() But from the nature of your questions I'd respectfully say that you're a LONG way from that point on a number of fronts. The only time you need to look at a lot of other options is when you're doing a specific contest model intended to deliver every last fraction of a % of performance. On the other hand most of our models can get away with and perform well with the good ol' standby, the Clark Y. Z-matrix, as the later answers are indicating there's a LOT to designing and picking airfoils. But as you and Norm are pointing out the real world answer is anything but simple. He asked a simple question so I tried to keep the answer simple. So for a heavy load wouldn't you choose a cambered airfoil because of its minimal drag at some positive AOA that you could choose either by airfoil shape or wing area? I'm not sure, but I'm guessing that the minimum drag for a symmetrical airfoil is a an angle of zero, but it is at some non-zero angle for cambered airfoils. ![]() Wouldn't drag be important? Can't you always increase the lift curve during take offs and landing, as DPATE said, using flaps. ![]()
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