viscosity_of_water

lumicks.pylake.viscosity_of_water

viscosity_of_water(temperature, molarity_nacl=None, pressure=None)

Computes the viscosity of water in [Pa*s] at a particular temperature, molality of NaCl and pressure.

These equations come from section 3.7 from [1]. When pressure and/or molality of NaCl are provided, equations from [2] are used. Note that the latter model has a slightly smaller valid temperature range.

Parameters:

• temperature (array_like) – Temperature [Celsius]. Should be between -20°C and 110°C

• molarity_nacl (float) – Molarity NaCl [mol/L].

• pressure (float, optional) – Pressure (default: 0.101325) [MPa].

Returns:

Viscosity of water [Pa*s]

Return type:

array_like

Raises:

• ValueError – If no molality or pressure is provided and the requested temperature is outside the valid range of -20°C <= T < 110°C.

• ValueError – When molality and/or pressure are also provided and the provided values are outside the valid range of this model. The valid ranges are: Temperature (20°C <= T < 150°C), pressure <= 35 MPa and molality <= 6 mol/kg.

References

[1]

Huber, M. L., Perkins, R. A., Laesecke, A., Friend, D. G., Sengers, J. V., Assael, M. J., & Miyagawa, K. (2009). New international formulation for the viscosity of H2O. Journal of Physical and Chemical Reference Data, 38(2), 101-125.

[2]

Kestin, J., Khalifa, H. E., & Correia, R. J. (1981). Tables of the dynamic and kinematic viscosity of aqueous NaCl solutions in the temperature range 20–150 C and the pressure range 0.1–35 MPa. Journal of physical and chemical reference data, 10(1), 71-88.