| Revision as of 01:32, 12 March 2002 edit212.250.215.13 (talk)No edit summary← Previous edit | Revision as of 04:41, 29 March 2002 edit undoTobias Hoevekamp (talk | contribs)Extended confirmed users2,321 edits added dynamic/kinematic and extended list of visocitiesNext edit → | ||
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| viscosity. | viscosity. | ||
| The viscosity of fluids is either given as dynamic viscosity η | |||
| ⚫ | Some viscosities of (newtonian) fluids are listed below |
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| (].] = ]/]/]) | |||
| or as kinematic viscosity ν (]^2/]). | |||
| Both terms are related via the ] ρ to each other: η = ν * ρ. | |||
| ⚫ | Some dynamic viscosities of (newtonian) ] are listed below: | ||
| :air 0.00001 Pa.s | |||
| :water 0.001 Pa.s | |||
| ] (at 0 ]): | |||
| :oil 100 Pa.s | |||
| :] 8.4*10<sup>-6</sup> Pa.s | |||
| :honey 10000 Pa.s | |||
| :] 17.4*10<sup>-6</sup> Pa.s | |||
| :] 21.2*10<sup>-6</sup> Pa.s | |||
| ] (at 20 ]): | |||
| :] 0.33*10<sup>-3</sup> Pa.s | |||
| :] 0.59*10<sup>-3</sup> Pa.s | |||
| :] 1.0*10<sup>-3</sup> Pa.s | |||
| :] 2.0*10<sup>-3</sup> Pa.s | |||
| :] 30*10<sup>-3</sup> Pa.s | |||
| :] 81*10<sup>-3</sup> Pa.s | |||
| :] 985*10<sup>-3</sup> Pa.s | |||
| :] 1485*10<sup>-3</sup> Pa.s | |||
| Contrary to many assertions, glass is an amorphous solid, not a liquid, and it does not flow. See the article on ] for more details on this. | Contrary to many assertions, glass is an amorphous solid, not a liquid, and it does not flow. See the article on ] for more details on this. | ||
| Many fluids like ] have a wide range of viscosity. | |||
Revision as of 04:41, 29 March 2002
Viscosity is a property of fluids describing its internal resitance to flow and may be thought of as fluid friction. If the viscosity of a fluid is constant (neglecting temperature and pressure effects) it is said to be a 'newtonian' fluid. Non-newtonian fluids exhibit a variation of viscosity depending on gradients within the flow field, the history that a fluid 'particle' experiences on its flow path, etc. If the viscosity of a fluid solely depends on the gradients within the flow field it is called generalized newtonian or purely newtonian. Rheology is the field of science that deals with viscosity.
The viscosity of fluids is either given as dynamic viscosity η (Pa.s = kg/m/s) or as kinematic viscosity ν (m^2/s). Both terms are related via the fluid density ρ to each other: η = ν * ρ.
Some dynamic viscosities of (newtonian) fluids are listed below:
- acetone 0.33*10 Pa.s
- methanol 0.59*10 Pa.s
- water 1.0*10 Pa.s
- nitrobenzol 2.0*10 Pa.s
- sulfuric acid 30*10 Pa.s
- olive oil 81*10 Pa.s
- ricinus oil 985*10 Pa.s
- glycerin 1485*10 Pa.s
Contrary to many assertions, glass is an amorphous solid, not a liquid, and it does not flow. See the article on glass for more details on this.
Many fluids like honey have a wide range of viscosity.