findMaximumRangeSpeed {afpt} | R Documentation |
This function performs a numerical optimization to find the airspeed for which P/U is minimum. For this it uses the function optimize
.
findMaximumRangeSpeed(bird,lower=NULL,upper=NULL,windSpeed=0,windDir=0,...)
bird |
bird description object (see |
lower |
lower speed limit (optional) |
upper |
upper speed limit (optional) |
windSpeed |
wind magnitude (in m/s; optional) |
windDir |
wind direction (in degrees; optional) |
... |
optional arguments: |
This function performs a numerical optimization to find the airspeed for which P/U is minimum. For this it uses the function optimize
. This airspeed is searched for between lower
and upper
(if not provided, it will make a guess based on bird
). Flying in wind changes the ground speed, and therefore the optimum flight speed for maximum range. This can be taken into account through the optional arguments for wind magnitude (windSpeed
in m/s) and wind direction relative to the track direction (windDir
in degrees; windDir = 0
tail wind); see e.g. Liechti et al. 1994.
Returns data.frame (power.chemical) of flight performance at maximum range speed for bird
.
Marco Klein Heerenbrink
Liechti, F., Hedenström, A. and Alerstam, T. (1994). Effects of Sidewinds on Optimal Flight Speed of Birds. J. Theor. Biol. 170, 219–225.
computeChemicalPower
, computeFlappingPower
## Define a bird: myBird = Bird( massTotal = 0.215, # (kg) total body mass wingSpan = 0.67, # (m) maximum wing span wingArea = 0.0652, # (m2) maximum wing area type = "passerine" ) maximumRangeSpeed.chem <- findMaximumRangeSpeed(myBird) maximumRangeSpeed.chem[c('speed','power','strokeplane','amplitude','frequency')] # speed power strokeplane amplitude frequency # 1 11.02543 14.32754 18.17729 36.69311 5.948083 maximumRangeSpeed.chem.wind <- findMaximumRangeSpeed( myBird, windSpeed = 5, windDir = 90 ) maximumRangeSpeed.chem.wind[c('speed','power','strokeplane','amplitude','frequency')] # speed power strokeplane amplitude frequency # 1 11.81974 15.47758 16.33727 38.17508 5.948083