Pa·s
pascal second
Dynamic viscosityexact by definition
The pascal second is the coherent SI unit of dynamic (absolute) viscosity, the ratio of shear stress to shear rate. Its factor is 1 by construction. It is a large unit for ordinary liquids: water at 20 °C is about 0.001 Pa·s, while honey is a few Pa·s.
Watch out: Dynamic viscosity (Pa·s) and kinematic viscosity (m²/s) are different quantities related by the density: \(\nu = \mu/\rho\). Reynolds number can be computed with either, using the matching form of the equation, but substituting one value for the other is a genuinely common and consequential error.
| 1 Pa·s | 1 Pa·s |
Solvers that use dynamic viscosity