HumanPoweredDesigner
Well-Known Member
1. Is the vast majority of the under side of typically laminar? What if they are symetric?
2. I read most airfoils are laminar in the first 15% of the top, and fully laminar on the bottom.
3. Is it true that the faster a wing travels, the less of it is laminar and the higher the drag coefficient? But I also heard the skin drag of higher Re wings is lower.
4. Is there such a thing as a fully laminar wing, or is there more of a spectrum of percentage laminar? Or is 50% usually the limit?
5. Was the daedalus wing laminar?
6. I read that to get laminar flow, you need the correct AoA, a small leading radius, and the thickest point further back. Does that typically reduce the coefficient of lift at L/D max? (I don't care about max L/D, which usually has high profile drag)
7. I read that around Re = 1,000,000, turbulent skin has 5x the drag as laminar skin. If the top trailing 85% of the wing is turbulent, making it laminar would reduce the skin drag by more than half.
One reason I'd prefer a conventional airfoil is so the lift is concentrated near the spar in front and I can make the ribs stronger there to take the tension in the mylar, without having to buff up the trailing edge so much.
Two reason I'd prefer a laminar flow airfoil are:
1. Less drag.
2. The whole airfoil will be higher and forward of the spar at the hub, so the highly pitched ribs by the hub don't crash into the body of the helicopter as they go around. I'd be happy with a turbulent foil if the spar could be placed mid cord.
2. I read most airfoils are laminar in the first 15% of the top, and fully laminar on the bottom.
3. Is it true that the faster a wing travels, the less of it is laminar and the higher the drag coefficient? But I also heard the skin drag of higher Re wings is lower.
4. Is there such a thing as a fully laminar wing, or is there more of a spectrum of percentage laminar? Or is 50% usually the limit?
5. Was the daedalus wing laminar?
6. I read that to get laminar flow, you need the correct AoA, a small leading radius, and the thickest point further back. Does that typically reduce the coefficient of lift at L/D max? (I don't care about max L/D, which usually has high profile drag)
7. I read that around Re = 1,000,000, turbulent skin has 5x the drag as laminar skin. If the top trailing 85% of the wing is turbulent, making it laminar would reduce the skin drag by more than half.
One reason I'd prefer a conventional airfoil is so the lift is concentrated near the spar in front and I can make the ribs stronger there to take the tension in the mylar, without having to buff up the trailing edge so much.
Two reason I'd prefer a laminar flow airfoil are:
1. Less drag.
2. The whole airfoil will be higher and forward of the spar at the hub, so the highly pitched ribs by the hub don't crash into the body of the helicopter as they go around. I'd be happy with a turbulent foil if the spar could be placed mid cord.
