Blue Storm
Name: Blue Storm
Date: February 2012
Material: R20 Pink Foam
Wingspan: 1000 mm
Wing root: SWIFT airfoil (from University of Toronto Aeronautics Team (UTAT) 2012 design), 235 mm root chord
Wing tip: e336 airfoil (UIUC database), 150 mm tip chord
Sweep: 30 degrees
Propeller: 7 x 3.5 or 8 x 4
Motor: 18T TowerPro brushless
Battery: Turnigy 3S 1100 mAh LiPo
Flying weight: 410 g
Design:
I got the idea of having two different airfoils across the wing (i.e. aerodynamic twist) from the University of Toronto Aeronautics Team (UTAT), in which I was an active participant. We wanted to have a zero pitching moment in level flight, which means the airplane would fly level with zero elevator trim. UTAT's flying wing used the e325 airfoil at the wing tip for its low drag characteristics, and the SWIFT airfoil in the centre section for its high left characteristics.
SInce I build my flying wings with a foam cutter, it is easier to make the whole wing the 'transition' section. So I cut wood templates for the SWIFT and e336 airfoils, pin them to the ends of a block of foam, and pass the foam cutter over the templates.
I chose the e336 airfoil based on an analysis using XFoil. I decided on the flying wing's other parameters (wingspan, root and tip chords, etc.) using a program called AVL. Both of these programs are frequently used by UTAT to design their planes. The AVL analysis provides the theoretical elevator trim needed to obtain a zero pitching moment, which in my case was 0.94 degrees. This is close enough to zero for my needs, and I decided to go ahead and start the construction.
Date: February 2012
Material: R20 Pink Foam
Wingspan: 1000 mm
Wing root: SWIFT airfoil (from University of Toronto Aeronautics Team (UTAT) 2012 design), 235 mm root chord
Wing tip: e336 airfoil (UIUC database), 150 mm tip chord
Sweep: 30 degrees
Propeller: 7 x 3.5 or 8 x 4
Motor: 18T TowerPro brushless
Battery: Turnigy 3S 1100 mAh LiPo
Flying weight: 410 g
Design:
I got the idea of having two different airfoils across the wing (i.e. aerodynamic twist) from the University of Toronto Aeronautics Team (UTAT), in which I was an active participant. We wanted to have a zero pitching moment in level flight, which means the airplane would fly level with zero elevator trim. UTAT's flying wing used the e325 airfoil at the wing tip for its low drag characteristics, and the SWIFT airfoil in the centre section for its high left characteristics.
SInce I build my flying wings with a foam cutter, it is easier to make the whole wing the 'transition' section. So I cut wood templates for the SWIFT and e336 airfoils, pin them to the ends of a block of foam, and pass the foam cutter over the templates.
I chose the e336 airfoil based on an analysis using XFoil. I decided on the flying wing's other parameters (wingspan, root and tip chords, etc.) using a program called AVL. Both of these programs are frequently used by UTAT to design their planes. The AVL analysis provides the theoretical elevator trim needed to obtain a zero pitching moment, which in my case was 0.94 degrees. This is close enough to zero for my needs, and I decided to go ahead and start the construction.
Construction:
I used the exact same construction techniques used to build FlyingWing2.
Flights:
Maiden flight was amazing - flew beautifully at 1/2 throttle
CG with 3 S 1100 mAh LiPo is 5 mm in front of Neutral Point (NP)
Crashed many times due to pilot error (I was teaching myself how to fly flying wings)
Calculated flight time: should not be longer than 4 min.
New battery: 3 S 2200 mAh LiPo
- Plane becomes very nose heavy (510 g flying weight)
- Wing tips stall during sharp turns at low speed => No aileron control
Big Mistake:
In order to see the orientation of the plane better, I painted the top of the wing black, and the bottom orange. However, I used spray paint directly on the foam, and the paint literally burned through the foam, destroying my wing. The surface of the wing is no longer smooth and the airfoil is distorted. The plane still flies, but there is so much drag, it's not fun to fly anymore. Lesson learned.
I used the exact same construction techniques used to build FlyingWing2.
Flights:
Maiden flight was amazing - flew beautifully at 1/2 throttle
CG with 3 S 1100 mAh LiPo is 5 mm in front of Neutral Point (NP)
Crashed many times due to pilot error (I was teaching myself how to fly flying wings)
Calculated flight time: should not be longer than 4 min.
New battery: 3 S 2200 mAh LiPo
- Plane becomes very nose heavy (510 g flying weight)
- Wing tips stall during sharp turns at low speed => No aileron control
Big Mistake:
In order to see the orientation of the plane better, I painted the top of the wing black, and the bottom orange. However, I used spray paint directly on the foam, and the paint literally burned through the foam, destroying my wing. The surface of the wing is no longer smooth and the airfoil is distorted. The plane still flies, but there is so much drag, it's not fun to fly anymore. Lesson learned.