findMaximumRangeSpeed {afpt} R Documentation

## Find maximum range speed

### Description

This function performs a numerical optimization to find the airspeed for which P/U is minimum. For this it uses the function `optimize`.

### Usage

```findMaximumRangeSpeed(bird,lower=NULL,upper=NULL,windSpeed=0,windDir=0,...)
```

### Arguments

 `bird` bird description object (see `Bird`) `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: `climbAngle` (in degrees), and optional arguments for `computeFlappingPower`.

### Details

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.

### Value

Returns data.frame (power.chemical) of flight performance at maximum range speed for `bird`.

### Author(s)

Marco Klein Heerenbrink

### References

Liechti, F., HedenstrĂ¶m, A. and Alerstam, T. (1994). Effects of Sidewinds on Optimal Flight Speed of Birds. J. Theor. Biol. 170, 219â€“225.

`computeChemicalPower`, `computeFlappingPower`

### Examples

```## 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
```

[Package afpt version 1.1.0.1 Index]