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May 17, 2004, 12:03 PM
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sloper steve's Avatar
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Rave

Flying wing design formulas


I'd like to use math to determine necessary sweep for the flying wing given a centralized component weight and position, cg before adding components and the aerodynamic center.

I have Profili and Java foil and believe programs exist that tell the aerodynamic center.

Some sites with wing formulas:
http://slofly.com/z/index.php?catego...20wing%20links
http://www.mh-aerotools.de/airfoils/flywing1.htm
http://members.lycos.co.uk/A75Church/tips3.htm
http://members.cox.net/twitt.02/HoeyCalcs.html

Thanks
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May 17, 2004, 02:41 PM
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Quote:
Originally Posted by sloper steve
I'd like to use math to determine necessary sweep for the flying wing given a centralized component weight and position, cg before adding components and the aerodynamic center.
Thanks
Hi Steve,

I'm not sure I quite understand what you are trying to do....you'd like to do the calculation of the sweep last?
I usually start by estimating the weight of the wing, the intended speed range (which will dictate the airfoil used), span, aspect ratio, the stability factor (.05 in most cases) and a pretty close estimate of the sweep (I usually avoid anything above 20 degrees)...from all of that I calculate the twist needed.

Are you more worried about not being able to get the wing balanced at the CG without using lead?

Regards,

Bernie
May 17, 2004, 04:59 PM
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MikeC's Avatar
Steve go here;

http://www.b2streamlines.com/Panknin.html

There will be a small program named Twist for either a Mac or IBM that will give you the info you need....I think. I have used it on a 120" thermal flying wing and it worked fine.

Mike
May 19, 2004, 11:34 AM
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JMP_blackfoot's Avatar
You could also check at the bottom of this thread for my Horten bell distribution formula :

https://www.rcgroups.com/forums/showthread.php?t=231874
May 22, 2004, 03:15 PM
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sloper steve's Avatar
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Thanks all.

Bernie,

Yes I'm trying to design so no lead is needed for balance.

A step by step method to solve this questions like this sure would help.

To make things easier consider a flying wing with slight dihedral and no elevons that is made to be a glider you toss on your driveway.

How much sweep (tip back from nose in inches) must a 40" span, 10" root, 6" tip, 1 degree tip twist flying wing have using NACA ___ airfoil at the root and tips with __ thickness at root and ___ thickness at tip? For level flight at around 10mph.

Given 1oz of weight added 1" behind nose what should the sweep be adjusted to?
Given 1oz of weight added 1" in front of the trailing edge what should the sweep be adjusted to?

Example:
Step 1:
Get your wings CG and NP using this program
Step 2: ?
May 24, 2004, 12:54 AM
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When the excel spread sheets ask for sweep...what exactly do they want. What about a delta wing?
May 24, 2004, 01:37 AM
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MikeC's Avatar
With the Twist program, sweep is calculated at the 1/4 chord line from root to tip(in degrees). Have never tried Twist with a delta wing.
Last edited by MikeC; May 24, 2004 at 09:34 AM.
May 27, 2004, 02:45 AM
Robots... robots everywhere
minifly's Avatar
some good calculators at coloradogliders.com
May 27, 2004, 02:47 AM
Robots... robots everywhere
minifly's Avatar
sorry,
http://www.coloradogliders.com/tools.htm
May 27, 2004, 10:08 AM
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Thats was exactly what I was looking for...thanks!
Jun 19, 2004, 11:42 PM
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sloper steve's Avatar
Thread OP

Sweep flying wing designer applet


This is an applet I'm working on to design flying wings check it out.
Any help with the math is appreciated.
There is lots of room for criticism but please don't it may destroy my motivation

Sweep flying wing designer applet
Jun 19, 2004, 11:47 PM
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sloper steve's Avatar
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Balance calculator


Design a wing around your components and have it fly with no addional ballast at neutral trim on the first toss!

using work=force*distance for components, lift, elevon force from cg balance can be calculated for various speeds an applet will let you input the component weights and slide their positions to see if they can work with your planes CG, Neutral point and moments.

Various information about your airfoil, sweep and twist will be required.
I will start programming the applet in a few days/years
Last edited by sloper steve; Jun 20, 2004 at 12:23 AM.
Aug 05, 2004, 12:30 PM
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sloper steve's Avatar
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Any help with the math?
Sep 26, 2011, 10:16 AM
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thanks


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