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#1 |
New Member
Join Date: Aug 2011
Posts: 17
Rep Power: 15 ![]() |
Dear forum members,
I'm working on a double element wing, and I would like to know if there is a way to get reliable results for a wing with a gurney? As I know that it's not possible to simulate multi element airfoils in X-Foil, I separate them and also simulate separatly, but on some way, X-Foil doesn't get the right chord lenght. So the simulation totally fails. I organize all coordinates in Excel, so maybe there are some tricks to do it better. Thanks. |
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#2 |
Senior Member
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Why do not you fix the chord lenghth of each airfoil and change reynolds number instead?
What problem are you solving exactly? Is it a gurney flap which is separated from main airfoil? X-foil could be not a good choise for such kind of problems. Truffaldino |
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#3 |
New Member
Join Date: Aug 2011
Posts: 17
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Well is there a way to change the chord length in X-Foil? The gurney is attached to the foil, so there are no gaps.
The problem is that X-Foil thinks that the gurney flap, is the chord length and doesn't recognize the LE. The thing I would like to know is, if there's a proper way to put in the coordinates in Excel to let X-Foil recognize the right LE and TE. Thanks. |
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#4 | |
Senior Member
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Quote:
Bad panelling coul be also eliminated by tiny rounding the right angle. For sure, your coordinate loading problem can be easily fixed, but it is not the main problem with x-foil. The real problem is more fundamental: the methods X-foil uses are not fitted for analyzing gurney flaps, and results you will get could have nothing to do with reality. X-foil is based on integral boundary methods that do not handle vorticity regions that you have at gurney flaps, corners, steps etc. Truffaldino |
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#5 | |
New Member
Jose
Join Date: Jan 2014
Posts: 1
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Quote:
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#6 |
Senior Member
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Here it is. you could do fine repanelling (using standard x-foil/xflr procedures) closer to the flap
Last edited by truffaldino; January 17, 2014 at 13:57. Reason: wrong attached file |
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#7 |
Senior Member
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I agree with truffaldino, what you are doing cannot be done with x-foil for two reasons:
1. It cannot handle multi element wings and the behavior of a main plane + flap all together is totally different from the behavior of each one of them alone since they influence each other. 2. A gurney tab works because of the flow separation it creates and this is not handled by X-foil |
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Tags |
airfoils, element, multo, wings, x-foil |
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