General design approach
short version
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General design approachshort version |
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General approach – short
version 1.
Settle on span, minimum flying speed and an
airfoil with a known critical renoylds number 2.
Calculate the tip chord at 90% span (formula 1) 3.
Settle on a root chord and calculate ”Tau” (formula
2) 4.
Determine where along the span, you want to know
the specific chords. 5.
Calculate these chords (formula 3) 6.
Calculate area and aspect ratio (formula 4b and
4a) 7.
Calculate the minimum efficient flying weight (formula
5) 8.
Calculate the wing loading (formula 6) 9.
Check the chosen airfoils camber with the wing
loading 10. Be
satisfied or change something during the way. Don’t
cry if you didn’t get this the first time you read it – and if you
did I don’t want to hear about it, because I spent hours reading about,
finding out all these things, and creating the ellipse modifying-tool. How
do I know my tool is right?? Well, I compared a lot of known great
models plan form with my ellipse modifying tool, and if these models
work, so does my tool! If there is somebody who know more than I do, who
can give me a better answer (or a correction), I would be glad to know
– even a teacher can learn. And I have compared and checked the lift
distributions of the wing forms I have made with another Excel
spreadsheet made by John Hazel and Bas Breyer (11th at the
1998 F3J WC at Upton), and they all come out very close to their
elliptical lift distribution. And
an elliptical lift distribution is good enough for me. At this homepage you can find the excel spreadsheet made by John Hazel and
Bas Breier, which can calculate the lift distribution of your new wing: http://vvt.kohrman.wmich.edu/lab/people/LIFTDIST.html This is my way, which have learnt me a lot about
the interference of the many design parameters, but there is of course
others, for example a well known and widely used design philosophy,
formulated by the famous American, Dave Thornburg – Old Buzzard: 1.
If it looks right, it probably is
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