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Old 08-17-2013, 04:44 PM   #11 (permalink)
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Okay,used faster computer and got them in

With faster machine I was able to get the two new tables posted.Again,I'm placing all tables together up top @ #1 permalink.
*These are for wing/strut section 2-D flow, drag as a function of trailing edge truncation.
*The delta-C is a function of the entire wing chord,not just the trailing portion.
*The formula for calculating the new Cd is presented as a function of section thickness only.
*Any section which has it's maximum thickness at around 30% of chord is fair game.
*A sample calculation is presented for a 20.5% thickness G'o'ttingen airfoil.
*I've reversed the original table so as to always have the body attacking the air from left-to-right,as in the other tables.
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*The second table is a drag curve calculated from the equation using the G'o'ttingen airfoil shown.
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'WARNING Will Robinson!!!!!!!!!!!!!!'
Sections don't behave as streamline bodies or half-bodies.
*They suffer tremendous drag increase with a 'Kamm' truncation of any amount.
*It's better to pull the sides into a boat tail even if it's too steep.
*I've got another section table for this 'J',or Jaray-form section treatment in the works and will try for next Saturday to post.
*This research was conducted by K-Fachsenfeld at the FKFS (now Mercedes-Benz' wind tunnel) under the supervision of Kamm.
*Junkers did similar studies and I've got that to look at also.

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Old 08-24-2013, 03:58 PM   #12 (permalink)
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New drag table added

I've added a working drawing for wing/strut sections which are shortened in,as Kamm referred to them as the J-form,or,Jaray-form.
It appears at the thread top,and you'll see distinctly lower Cds than with K-form truncated sections.
If you're going after Craig Vetter type efficiencies,this is how you'll want to do it.

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