Dynamic viscosityUnits Type ⤴

The dynamic (shear) viscosity of a fluid expresses its resistance to shearing flows, where adjacent layers move parallel to each other with different speeds. Both the physical unit of dynamic viscosity in SI Poiseuille (Pl) and the cgs units Poise (P) come from Jean Léonard Marie Poiseuille. The poiseuille, which is never used, is equivalent to the pascal-second (Pa·s), or (N·s)/m2, or kg/(m·s).