# Dynamic viscosity of water

The dynamic viscosity (also called absolute viscosity) is used to calculate Reynolds Number to determine if a fluid flow is laminar, transient or turbulent.

The sources are:

• Values for seawater are taken from the engineering toolbox .
• Values for fresh water are taken from the engineering toolbox .
• Equations for seawater and fresh water are third-degree polynominal functions for the given values.

Symbol
$\eta_{w}$
Unit
Pa.s
Formulae
 $\nu_{w} \rho_{w}$ general equation $- 1.3333 \cdot 10^{-8} \theta_{w}^{3} + 1.2784 \cdot 10^{-6} \theta_{w}^{2} - 6.0181 \cdot 10^{-5} \theta_{w} + 0.001888$ seawater $- 1.2949 \cdot 10^{-8} \theta_{w}^{3} + 1.2858 \cdot 10^{-6} \theta_{w}^{2} - 6.0068 \cdot 10^{-5} \theta_{w} + 0.001791$ fresh water
Related
$\nu_{w}$
$\rho_{w}$
Density of water [kg/m$^3$]
$\theta_{w}$
Water temperature [$^{\circ}$C]
Used in
$\nu_{w}$
Choices
Liquid0.01$^{\circ}$C5$^{\circ}$C10$^{\circ}$C15$^{\circ}$C20$^{\circ}$C25$^{\circ}$C30$^{\circ}$C
Seawater0.001890.001610.001410.0012210.001090.000970.00087
Fresh water0.00179140.0013060.00100160.000890.0007972