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Oct 03, 2016, 03:34 PM
InceCreations
vincent123's Avatar
Blended wing body design ?
just blended the batteries out
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Oct 07, 2016, 01:30 PM
InceCreations
vincent123's Avatar
Wing estimate, without fuselage

1235gr including EDFs and motors
835gr without EDF and motors
of which 200gr is carbon (50gr per carbon spar x 4)

I could shave 50 gr by reducing the carbon thickness, this woud reduce the max. G's from 18G to 14G.

Any thoughts ?
Oct 07, 2016, 02:19 PM
Registered User
iron eagle's Avatar
Actually your weigh doesn't seem all that bad.
I thought you had planned on a AUW of 2900 g for that wing area anyhow?
If there is a real possibility if it going to be a fast airplane, stick with the stronger setup, it will resist "Body Freedom Flutter" a lot better. And flutter with a flying wing can be a real killer.
I did have a thought regarding servos and control linkages. If you could move the engine nacelles a bit further outboard (where the wing bends downward) you could incorporate the servos,horns and linkages within the engine nacelle much in the same manner I did with my delta with the pull pull linkages.
Oct 07, 2016, 02:57 PM
InceCreations
vincent123's Avatar
AUW is about 3000gr, but possibly I'll end up a bit more.
Nevertheless, I should have more than 4000gr of thrust. So that's ok, and with the FZ5 experience, I learned in fact that weight is not 'that' much important: the FZ5 wing is more than capable to carry his weight and flies very light weight.

The servo setup is is my classic approach, I'll take the HITEC HS-5070MH.

Just done estimating wing COG, seems I have to push the batteries 60mm up front to get even balance: or I extent the fuselage , resulting in a higher nose leg wheel, has its limits, or I make the fuselage wider to acccomodate 2 batteries side by side..., or I take one big battery .. hmm
Oct 08, 2016, 07:06 AM
InceCreations
vincent123's Avatar
Ha, found a solution !

shifted the ESC's below the battery, so I can leave the battery where it was !
Oct 08, 2016, 07:39 AM
You know nothing....
Stuart A's Avatar
Neat!You should be able to get some airflow over them in that position.
Oct 09, 2016, 03:11 AM
InceCreations
vincent123's Avatar
Thx, Stu.

Any ideas about the vertical empennage ?

Sizing is about double for what I would normally take as winglet.

Moment arm to CG, taken in order to have the same stability index (p 190 Taileless tale) as what I would take for winglets ...

So this should result in a good directional stability.
Oct 09, 2016, 05:56 AM
InceCreations
vincent123's Avatar
Vertical empennage is 40mm at the base, airfoil planform, too thick ?
Oct 09, 2016, 07:23 AM
You know nothing....
Stuart A's Avatar
Here's a link I came across a while ago
http://www.charlesriverrc.org/articl...ilairfoils.htm
Sounds like the thinner the better,bearing in mind the structure needed.
Oct 09, 2016, 08:53 AM
InceCreations
vincent123's Avatar
Great Stu, I immediately applied the H14 profile, wingbase of the VT is now 30mm
Oct 09, 2016, 01:15 PM
Registered User
iron eagle's Avatar
Now that looks like a hot airplane!
Oct 09, 2016, 02:42 PM
InceCreations
vincent123's Avatar
Ok, thanks !
Oct 10, 2016, 02:27 PM
InceCreations
vincent123's Avatar
Quote:
Originally Posted by vincent123
Great Stu, I immediately applied the H14 profile, wingbase of the VT is now 30mm

Can't do it, the airfoil is too thin and the thickest point is too close to the LE. Got difficulties to model it, so that I can make it in a decent way.

Thinking of the NACA 0009 as an alternative
Oct 12, 2016, 01:43 PM
InceCreations
vincent123's Avatar
Not easy to model a narrow sweeped vertical stab.

Took the NACA0009

Anchoring in the fuselage is for later.
Last edited by vincent123; Oct 12, 2016 at 02:42 PM.
Oct 15, 2016, 09:52 AM
InceCreations
vincent123's Avatar
Ready to start designing the formers and battery plate of the fuselage...


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