Dynamic Viscosity¶

The dynamic viscosity is a property of the fluid, defining the resistance of the fluid to its own movement. The dynamic viscosity is calculated using the Sutherland formula (reference). The function can be found and is documented in util.dynamic_viscosity.py. It takes inputs of temperature, reference_viscosity, reference_temperature, and sutherland_constant. It returns a value for the dynamic viscosity at those variables. At default conditions (298.15 K and 101325 Pa), the dynamic viscosity is approximately 1.84e-5 kg/m/s. The Sutherland formula is

$$ \mu = \frac{\mu_{0}\, (T/T_{0})^{3/2}\, (T_{0} + C)}{C + T} $$

where $\mu$ is the dynamic viscosity, $\mu_{0}$ is the reference dynamic viscosity, $T$ is temperature, $T_{0}$ is the reference temperature, and $C$ is the Sutherland constant.

In [1]:

from particula.gas.properties import get_dynamic_viscosity

air_dynamic_viscosity = get_dynamic_viscosity(
    temperature=298.15
)  # will produce approx 1.84e-5 kg/m/s

print(f"Air dynamic viscosity at 298.15 K is {air_dynamic_viscosity:.2e} kg/m/s")

from particula.gas.properties import get_dynamic_viscosity air_dynamic_viscosity = get_dynamic_viscosity( temperature=298.15 ) # will produce approx 1.84e-5 kg/m/s print(f"Air dynamic viscosity at 298.15 K is {air_dynamic_viscosity:.2e} kg/m/s")

Air dynamic viscosity at 298.15 K is 1.84e-05 kg/m/s