Poiseuille

For the physicist, seeJean Léonard Marie Poiseuille.For Poiseuille flow, seeHagen–Poiseuille equation.

Poiseuille
Unit of	viscosity
Symbol	Pl
Named after	Jean Léonard Marie Poiseuille
Dimension	${\mathsf {M}}{\mathsf {L}}^{-1}{\mathsf {T}}^{-1}$
Conversions
1 Plin...	... is equal to...
SI base units	1kg⋅m−1⋅s−1

Thepoiseuille(symbolPl) has been proposed as aderived SI unitofdynamic viscosity,named after the French physicistJean Léonard Marie Poiseuille(1797–1869).

In practice the unit has never been widely accepted and most international standards bodies do not include the poiseuille in their list of units. The third edition of theIUPAC Green Book,for example, lists Pa⋅s (pascal-second) as the SI-unit for dynamic viscosity, and does not mention the poiseuille.

The equivalent CGS unit, thepoise,symbol P, is most widely used when reporting viscosity measurements.

$1\ {\text{Pl}}=1\ {\text{Pa}}{\cdot }{\text{s}}=1{\text{kg}}/{\text{m}}{\cdot }{\text{s}}=1{\text{N}}{\cdot }{\text{s}}/{\text{m}}^{2}=10\ {\text{dyn}}{\cdot }{\text{s}}/{\text{cm}}^{2}=10\ {\text{P}}$

Liquid water has a viscosity of0.000890Plat 25 °C (77 °F) at a pressure of1atm(0.000890Pl=0.00890P=0.890 cP=0.890 mPa⋅s).

Bibliography

• François Cardarelli (2004).Encyclopaedia of Scientific Units, Weights and Measures.Springer-Verlag London Ltd.ISBN978-1852336820