amplitude {afpt} | R Documentation |
This function returns the angular peak amplitude of the flapping motion, optimized for minimum induced power for prescribed reduced frequency (kf), strokeplane angle (phi), and thrust-to-lift ratio (TL).
amplitude(kf, phi, TL)
Using f for wingbeat frequency, b for wingspan, and U for air speed:
kf |
reduced frequency (kf = 2 * π * f *b / U); valid range between 1 and 6 |
phi |
strokeplane angle in radians; valid range between 0 and 0.87 rad (50 deg) |
TL |
thrust requirement or the trust-to-lift ratio; valid range between 0 and 0.3 |
Angular peak amplitude of the flapping motion in degrees.
Marco Klein Heerenbrink
Klein Heerenbrink, M., Johansson, L. C. and Hedenström, A. 2015 Power of the wingbeat: modelling the effects of flapping wings in vertebrate flight. Proc. R. Soc. A 471, 2177 doi: 10.1098/rspa.2014.0952
## reduced frequency kf <- 2*pi*4/10 # 4 Hz at 10 m/s for 1m wing span ## strokeplane angle phi <- 20*pi/180 # 20 degrees ## thrust ratio TL <- 0.2 ## wingbeat amplitude theta <- amplitude(kf,phi,TL) print(theta) # [1] 49.17679