def alt2dynamic_viscosity(H, alt_units=default_alt_units,
dynamic_viscosity_units=default_dynamic_viscosity_units):
"""
Return dynamic viscosity given the altitude.
"""
T = alt2temp(H, alt_units=alt_units)
u = temp2dynamic_viscosity(T)
# add unit conversion for result
u = U.dynamic_viscosity_conv(u, 'Pa s', dynamic_viscosity_units)
return u
def temp2dynamic_viscosity(T, temp_units=default_temp_units,
dynamic_viscosity_units=default_dynamic_viscosity_units):
"""
Return dynamic viscosity given the air temperature.
Formula from US Standard Atmosphere, 1976 section 1.3.11 on page 19.
"""
T = U.temp_conv(T, temp_units, 'K')
u = 1.458e-6 * T**1.5 / (T + 110.4)
u = U.dynamic_viscosity_conv(u, 'Pa s', dynamic_viscosity_units)
return u
def alt2dynamic_viscosity(
H,
alt_units=default_alt_units,
dynamic_viscosity_units=default_dynamic_viscosity_units):
"""
Return dynamic viscosity given the altitude.
"""
T = alt2temp(H, alt_units=alt_units)
u = temp2dynamic_viscosity(T)
# add unit conversion for result
u = U.dynamic_viscosity_conv(u, 'Pa s', dynamic_viscosity_units)
return u
def kinematic_viscosity(density, dynamic_viscosity,
kinematic_viscosity_units=default_kinematic_viscosity_units,
density_units=default_density_units,
dynamic_viscosity_units=default_dynamic_viscosity_units):
"""
Return kinematic viscosity given density and dynamic viscosity.
"""
density = U.density_conv(density, density_units, 'kg/m**3')
dynamic_viscosity = U.dynamic_viscosity_conv(dynamic_viscosity, dynamic_viscosity_units, 'Pa s')
kinematic_viscosity = dynamic_viscosity / density
kinematic_viscosity = U.kinematic_viscosity_conv(kinematic_viscosity, 'm**2/s', kinematic_viscosity_units)
return kinematic_viscosity
def temp2dynamic_viscosity(
T,
temp_units=default_temp_units,
dynamic_viscosity_units=default_dynamic_viscosity_units):
"""
Return dynamic viscosity given the air temperature.
Formula from US Standard Atmosphere, 1976 section 1.3.11 on page 19.
"""
T = U.temp_conv(T, temp_units, 'K')
u = 1.458e-6 * T**1.5 / (T + 110.4)
u = U.dynamic_viscosity_conv(u, 'Pa s', dynamic_viscosity_units)
return u
def kinematic_viscosity(
density,
dynamic_viscosity,
kinematic_viscosity_units=default_kinematic_viscosity_units,
density_units=default_density_units,
dynamic_viscosity_units=default_dynamic_viscosity_units):
"""
Return kinematic viscosity given density and dynamic viscosity.
"""
density = U.density_conv(density, density_units, 'kg/m**3')
dynamic_viscosity = U.dynamic_viscosity_conv(dynamic_viscosity,
dynamic_viscosity_units,
'Pa s')
kinematic_viscosity = dynamic_viscosity / density
kinematic_viscosity = U.kinematic_viscosity_conv(
kinematic_viscosity, 'm**2/s', kinematic_viscosity_units)
return kinematic_viscosity
