get_collisions_extended {stochLAB}

Number of collisions based on the extended model

Description

Calculates the expected number of collisions under the extended model, i.e. taking into account the distribution of bird flight heights at risk height (above the minimum and below the maximum height of the rotor blade)

Usage

get_collisions_extended(
  rotor_grids,
  d_y,
  rotor_radius,
  blade_width,
  rotor_speed,
  blade_pitch,
  flight_type,
  wing_span,
  flight_speed,
  body_lt,
  n_blades,
  prop_upwind,
  avoidance_rate,
  flux_factor,
  mth_prop_oper,
  lac_factor
)

Arguments

rotor_grids

A list object containing geometric attributes of the rotor at equidistant points within its unit circle. This object should be built via the function generate_rotor_grids().

d_y

a vector with the proportion of birds at height bands within the rotor disc

rotor_radius

Numeric value. The radius of the rotor (R), in metres.

blade_width

Numeric value, giving the maximum blade width, in metres.

rotor_speed

Numeric value. The operational rotation speed, in revolutions/min.

blade_pitch

Numeric value. The average blade pitch angle, the angle between the blade surface and the rotor plane (\gamma), in radians.

flight_type

A character string, either 'flapping' or 'gliding', indicating the species' characteristic flight type.

wing_span

Numeric value. The wingspan of the bird (W), in metres.

flight_speed

Numeric value. The bird flying speed (v), in metres/sec.

body_lt

Numeric value. The length of the bird (L), in metres.

n_blades

An integer, the number of blades in rotor (b).

prop_upwind

Numeric value between 0-1 giving the proportion of flights upwind - defaults to 0.5.

avoidance_rate

a numeric value within the interval [0, 1]. The avoidance rate, expressing the probability that a bird flying on a collision course with a turbine will take evading action to avoid collision.

flux_factor

a vector containing the flux factor for each month

mth_prop_oper

A numeric vector, the proportion of time during which turbines are operational per month.

lac_factor

A numerical value, the large array correction factor. Defaults to 1, meaning large array correction is not applicable.

Value

Numeric vector with the expected number of collisions per month based on the extended model

Note

The original Masden code for extendend model (Option 3) included the calculation of the "Flux Integral" and "Average collision risk for single rotor transit". These quantities are not required for the calculation of collisions under the extended model, nor are used anywhere else in the package. Therefore, those calculations were dropped from the current implementation to keep computations to a minimum required.

See Also

generate_rotor_grids()

Examples

 rotor_grids <- generate_rotor_grids(yinc = 0.05, xinc = 0.05, chord_prof_5MW)

 gen_fhd_dat <- Johnston_Flight_heights_SOSS %>%
      dplyr::filter(variable=="Gannet.est") %>%
      dplyr::select(height,prop)

 gen_fhd <- gen_fhd_dat$prop

 gen_fhd_at_rotor <-
    get_fhd_rotor(
      hub_height = 150,
      fhd = gen_fhd,
      rotor_radius = 120,
      tidal_offset = 2.5,
      yinc = 0.05)


 flux_fct <- get_flux_factor(
      n_turbines = 100,
      rotor_radius = 120,
      flight_speed = 13.1,
      bird_dens = c(1.19,0.85,1.05,1.45,1.41,1.45,1.12,1.45,0.93,0.902,1.06,1.23),
      daynight_hrs = Day_Length(52),
      noct_activity = 0.5
      )

turb_oper <- data.frame(
   month = month.abb,
   prop_oper = runif(12,0.5,0.8)
   )
turb_oper_month <- turb_oper$prop_oper

get_collisions_extended(
  rotor_grids = rotor_grids,
  d_y = gen_fhd_at_rotor, # ... with generic FHD = Option 3, with site FHD = Option 4
  rotor_radius = 120,
  blade_width = 5,
  rotor_speed = 15,
  blade_pitch = 15,
  flight_type = "flapping",
  wing_span = 1.01,
  flight_speed = 13.1,
  body_lt = 0.85,
  n_blades = 3,
  prop_upwind = 0.5,
  avoidance_rate = 0.981,
  flux_factor = flux_fct,
  mth_prop_oper = turb_oper_month,
  lac_factor = 0.9998299
  )