The usual way to find the mean chord is to take the area of the wing or stab and divide this number by the span. In other words, the wing/stab area is equal to the span times the mean chord. Since most of the calculations used in the various design programs involve linear approximations for those terms using the chords, the mean chord is often a good approximation in the calculations. The real concern, sometimes over looked in the design programs, is with finding the aerodynamic center for those wings/stabs with varing chords. An often used way is to find the aerodynamic center of the wing/stab section where the section chord is equal to the mean chord. Again, where linear terms are involved, this is a good approximation.
Leo
Bloomington IN
--- In Indoor_Construction_at_yahoogroups.com, "Brett Sanborn" <bsanborn@...> wrote:
>
> Don,
>
>
>
> Long time listener first time caller.
>
>
>
> In the design spreadsheet, how do we deal with the "mean tailchord" entry?
> For example, the maximum tail chord on my f1d is 5.25" but when I average
> the chord at the center and tip (since my stab is swept like a Coslick ezb
> stab) I get something like 3.8". Then when I try both of these values, I get
> a large difference in the static margin. My concern is that when I try the
> smaller "average" value, my static margin becomes negative.
>
>
>
> How should I deal with the stab geometry in the spreadsheet?
>
>
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> Thanks,
>
> Brett Sanborn
>
Received on Fri Jan 14 2011 - 08:46:03 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:46 CET