The function estimates the Grashof Number, which describes the ability of a parcel of fluid warmer or colder than the surrounding fluid to rise against or fall with the attractive force of gravity (Gates 1980) . The Grashof Number is estimated as the ratio of a buoyant force times an inertial force to the square of a viscous force.
Grashof_number_Gates(T_a, T_g, beta, D, nu)numeric Air temperature (C).
numeric Ground (surface) temperature (C).
numeric coefficient of volumetric thermal expansion, beta = 3.67 x 10-3 C-1 in air and 41.9 x 10-4 C-1 in water.
numeric is characteristic dimension (e.g., body diameter) (m)
numeric is the kinematic viscosity, the ratio of dynamic viscosity to density of the fluid (m2 s-1); can calculate from DRYAIR or WETAIR.
numeric Grashof number.
Gates DM (1980). Biophysical Ecology. Springer-Verlag, New York, NY, USA.
Other biophysical models:
Grashof_number(),
Nusselt_from_Grashof(),
Nusselt_from_Reynolds(),
Nusselt_number(),
Prandtl_number(),
Qconduction_animal(),
Qconduction_substrate(),
Qconvection(),
Qemitted_thermal_radiation(),
Qevaporation(),
Qmetabolism_from_mass_temp(),
Qmetabolism_from_mass(),
Qnet_Gates(),
Qradiation_absorbed(),
Qthermal_radiation_absorbed(),
Reynolds_number(),
T_sky(),
Tb_CampbellNorman(),
Tb_Gates2(),
Tb_Gates(),
Tb_butterfly(),
Tb_grasshopper(),
Tb_limpetBH(),
Tb_limpet(),
Tb_lizard_Fei(),
Tb_lizard(),
Tb_mussel(),
Tb_salamander_humid(),
Tb_snail(),
Tbed_mussel(),
Tsoil(),
actual_vapor_pressure(),
boundary_layer_resistance(),
external_resistance_to_water_vapor_transfer(),
free_or_forced_convection(),
heat_transfer_coefficient_approximation(),
heat_transfer_coefficient_simple(),
heat_transfer_coefficient(),
saturation_vapor_pressure(),
saturation_water_vapor_pressure()
Grashof_number_Gates(T_a = 30,
T_g = 35,
beta = 0.00367,
D = 0.001,
nu = 1.2)
#> [1] 1.248819e-10