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Howto:Make a helicopter: Difference between revisions
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Add links for calculation spreadsheets.
(→rotorgear: Explanation of yasim drag factor.) |
(Add links for calculation spreadsheets.) |
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* '''airfoil-drag-coefficient1:''' dragcoef1 | * '''airfoil-drag-coefficient1:''' dragcoef1 | ||
To find the right values: see README.yasim.rotor.ods (Open Office file) or README.yasim.rotor.xls (Excel file). | To find the right values: see [https://sourceforge.net/p/flightgear/fgdata/ci/next/tree/Docs/README.YASim.rotor.ods?format=raw README.yasim.rotor.ods] (Open Office file) or [https://sourceforge.net/p/flightgear/fgdata/ci/next/tree/Docs/README.YASim.rotor.xls?format=raw README.yasim.rotor.xls] (Excel file).<br />With theses files you can generate graphs of the airfoil coefficients and adjust the parameters to match real airfoils. For many airfoils you find data published in the internet. Parameters for the airfoils NACA 23012 (main rotor of bo105) and NACA 0012 (tail rotor of bo105?) are included. | ||
* '''rotor-correction-factor:''' If you calculate the lift of a heli rotor or even of a propeller, you get a value larger than the real measured one. (Due to vortex effects.) This is considered in the simulation, but with a old theory by Prantl, which is known to give still too large. This is corrected by this token, default: 1 | * '''rotor-correction-factor:''' If you calculate the lift of a heli rotor or even of a propeller, you get a value larger than the real measured one. (Due to vortex effects.) This is considered in the simulation, but with a old theory by Prantl, which is known to give still too large. This is corrected by this token, default: 1 | ||