For a Newtonian fluid
, the shear viscosity
is often termed simply viscosity
since in most situations it is the only one considered. It relates the shear components
of stress and those of rate of strain
at a point in the fluid by:
, the shear component of rate of strain
is defined as follows:
Corresponding relations hold for
is the component of stress acting in the
-direction on a plate normal to the
are the components of velocity.
PAC, 1979, 51, 1213
(Manual of symbols and terminology for physicochemical quantities and units. Appendix
II: Definitions, terminology and symbols in colloid and surface chemistry. Part 1.13.
Selected definitions, terminology and symbols for rheological properties)
on page 1216
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook