4 ms·
Potential flow theory tells us that the lift L is L = rho U Gamma, where rho is the air density, U the flight velocity, and Gamma the circulation, i.e. the tang
by bernulli 6y ago
Potential flow theory tells us that the lift L is L = rho U Gamma, where rho is the air density, U the flight velocity, and Gamma the circulation, i.e. the tangential velocity of the rotating surface times the circumference.
L is then only proportional to the radius, not to the square of the radius.
But it sure does produce enough lift to let things fly! https://www.youtube.com/watch?v=K6geOms33Dk&ab_channel=PeterSripol https://www.youtube.com/watch?v=K6geOms33Dk&ab_channel=Peter...
- carapace 6y agoDunno what to tell ya, I'm not an expert, Wikipedia says: Gamma = 2πr²ω where "ω is the angular velocity of spin of the cylinder (in radians / second) and r is the radius of the cylinder (in metres)." https://en.wikipedia.org/wiki/Magnus_effect https://en.wikipedia.org/wiki/Magnus_effect
- bernulli 6y agoOh interesting, I’ll need to look into where that discrepancy comes from!
- bernulli 6y agoOk, omega * R is what I referred to as tangential velocity, you’re right. I don’t know if that’s a useful way to look at it, though. It’s like saying “if I just made my car tires a mile in diameter, geez, I could be so much faster!”