Viscosity - DiracDelta Science & Engineering Encyclopedia

Viscosity

That molecular property of a fluid which enables it to support tangential stresses for a finite time and thus to resist deformation; the ratio of shear stress divided by shearing strain. A measure of the internal friction within a fluid. The time required for a liquid to drain out of a capillary tube is directly proportional to its viscosity.

The tangential force, F, required to move a layer of fluid, with viscosity, μ and area, A, at a constant velocity, v, for a given perpendicular distance from an immovable surface, s, is given by:

Force required to move a layer of viscous fluid with a constant velocity

*Conversions*
1 P (poise)	=	0.1 Nsm^-1	1 P	=	1 gcm^-1s^-1
1 cP (centipoise)	=	10^-3 kgm^-1s^-1	1 cP	=	1 mNsm^-2
1 lb ft^-1 h^-1	=	0.4132 mNsm^-2	1 slug ft^-1s^-1	=	47.88 Nsm^-2
1 Reyn	=	1 lbf s in^-2	1 Reyn	=	6895 Nsm^-2

The kinematic viscosity of a fluid is the dynamic viscosity of a fluid divided by the fluid density.

where

ν = kinematic viscosity [m²s^-1]

μ = dynamic viscosity [Nsm^-2]

ρ = density [kgm^-3]

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Acetic Acid	0.001219	Nsm^-2	Clip
Acetone	0.000324	Nsm^-2	Clip
Acetylene	0.00000935	Nsm^-2	Clip
Ammonia	0.00000918	Nsm^-2	Clip
Argon	0.000021	Nsm^-2	Clip
Benzene	0.000647	Nsm^-2	Clip
Bromine	0.000993	Nsm^-2	Clip
Carbon Dioxide	0.000014	Nsm^-2	Clip
Carbon Disulphide	0.000375	Nsm^-2	Clip
Carbon Monoxide	0.0000166	Nsm^-2	Clip
Carbon Tetrachloride	0.000972	Nsm^-2	Clip
Chlorine	0.0000129	Nsm^-2	Clip
Chloroform	0.000569	Nsm^-2	Clip
Cyanogen	0.00000928	Nsm^-2	Clip
Ethylene	0.0000097	Nsm^-2	Clip
Glycerol	1.495	Nsm^-2	Clip
Helium	0.0000186	Nsm^-2	Clip
Hydrogen	0.00000835	Nsm^-2	Clip
Hydrogen Chloride	0.0000138	Nsm^-2	Clip
Hydrogen Sulphide	0.0000117	Nsm^-2	Clip
Mercury Hg	0.001552	Nsm^-2	Clip
Methane	0.0000103	Nsm^-2	Clip
Methyl Alcohol	0.000594	Nsm^-2	Clip
Nitric Oxide	0.0000178	Nsm^-2	Clip
Nitrobenzene	0.00203	Nsm^-2	Clip
Nitrous Oxide	0.0000135	Nsm^-2	Clip
Olive Oil	84	Nsm^-2	Clip
Oxygen	0.0000192	Nsm^-2	Clip
Paraffin Oil	1	Nsm^-2	Clip
Phenol	0.01274	Nsm^-2	Clip
Sulphur Dioxide	0.0000117	Nsm^-2	Clip
Toluene	0.000585	Nsm^-2	Clip
Turpentine	0.00149	Nsm^-2	Clip
Water	0.001	Nsm^-2	Clip

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