Brief notes on the competing effects of sweep and anhedral
August 8, 2007 edition
Here are some brief notes on the competing effects of sweep and anhedral:
1) Sweep creates a dihedral-like effect. Flex-wing hang gliders have both sweep and anhedral. Therefore the roll torque that arises when we yaw a flex-wing hang glider to point to one side of the actual direction of the flight path and relative wind, will be determined by the competing effects of sweep and anhedral.
2) The dihedral-like roll torque created by sweep is known to be strongest when the wing the wing is operating at a high lift coefficient, i.e. at a high angle-of-attack.
3) The roll torque created by anhedral is known to be relatively independent of angle-of-attack.
4) Therefore the competing effects of sweep and anhedral will create a stronger anhedral effect or a weaker dihedral effect at low angles-of-attack (high airspeeds), and a weaker anhedral effect or stronger dihedral effect at high angles-of-attack (low airspeeds).