rtfm
Well-Known Member
Hi,
I've been using Design Foil to do some basic calcs on a planned wing for my project. However, I'm not sure I'm doing this right. What my approach is (so far), is as follows.
For example, I used the NACA747A315 airfoil - chosen because it has a relatively high Cl, a low Cd and a very low pitching moment. My projected empty weight is 450lbs and projected MAUW = 700lbs. I then sized my wing at 20' span, root = 3.5' tip = 3' giving area = 65sq ft. At 1.7 deg AoA I get 699lbs of lift @ 130kts, with a stall of 42kts (no flaps).
If I were to build my plane using these figures, could I expect performance figures similar to this? Or have I made typical Design Foil beginner mistakes?
Regards,
Duncan
I've been using Design Foil to do some basic calcs on a planned wing for my project. However, I'm not sure I'm doing this right. What my approach is (so far), is as follows.
- Pick an airspeed I would like to cruise at
- Select an airfoil
- Check the AoA required to produce lift equal to the MAUW
- Check that this AoA puts the drag in the drag bucket
For example, I used the NACA747A315 airfoil - chosen because it has a relatively high Cl, a low Cd and a very low pitching moment. My projected empty weight is 450lbs and projected MAUW = 700lbs. I then sized my wing at 20' span, root = 3.5' tip = 3' giving area = 65sq ft. At 1.7 deg AoA I get 699lbs of lift @ 130kts, with a stall of 42kts (no flaps).
If I were to build my plane using these figures, could I expect performance figures similar to this? Or have I made typical Design Foil beginner mistakes?
Regards,
Duncan
