findMaximumClimbRate {afpt}

Find maximum climb rate

Description

Numerically find the maximum attainable climb rate.

Usage

findMaximumClimbRate(bird, maximumPower, speed, ...)

Arguments

bird

bird description object (see Bird)

maximumPower

numeric value for maximum available mechanical power

speed

airspeed for which to compute the maximum climbrate

...

optional arguments for computeFlappingPower

Details

The function searches for a climb angle between -90 and 90 degrees that matches the specified maximum power available. If no speed provided, the function will also find the optimal airspeed for maximum climbrate.

Value

Data frame of class power.mechanical

speed

airspeed either prescribed or optimized for maximum climbrate

power

aerodynamic (mechanical) power matching maximum power

...

see computeFlappingPower for other variables

climbAngle

angle between flightpath and horizontal plane in degrees

climbRate

rate of vertical climb

Note

The function uses climb angle, rather than climb rate, in the search algorithm, to ensure that climb rate is always less than the airspeed (i.e. in a vertical climb the climb rate will simply equal airspeed). The actual climb rate is maximized by maximizing the product of climb angle and airspeed. However, in practice, the airspeed for best climb rate will be close to the minimum power airspeed, where the power margin is largest.

Author(s)

Marco Klein Heerenbrink

See Also

uniroot

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"
)

## maximum power available:
Paero.available <- computeAvailablePower(myBird)

climbSpeed <- 8 #  airspeed during climb

## find maximum climbrate:
Paero.climb <- findMaximumClimbRate(myBird,Paero.available,climbSpeed)
print(Paero.climb[c('speed','amplitude','frequency','climbRate')])
#   speed amplitude frequency climbRate
# 1     8  54.84965  5.948083  1.162002