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Consequently, if a liquid has dynamic viscosity of n centiPoise, and its density is not too different from that of water, then its kinematic viscosity is around n centiStokes. For gas, the dynamic viscosity is usually in the range of 10 to 20 microPascal-seconds, or 0.01 to 0.02 centiPoise. The density is usually on the order of 0.5 to 5 kg/m^3.
Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. [1] For liquids, it corresponds to the informal concept of thickness; for example, syrup has a higher viscosity than water. [2]
A heavy liquid is a solution or liquid chemical substance with a high density and a relatively low viscosity. Heavy liquids are often used for determination of density in mineralogy, for density gradient centrifugation and for separating mixtures .
Mānuka honey is an example of a thixotropic material.. Thixotropy is a time-dependent shear thinning property. Certain gels or fluids that are thick or viscous under static conditions will flow (become thinner, less viscous) over time when shaken, agitated, shear-stressed, or otherwise stressed (time-dependent viscosity).
The value of η ∞ represents the lowest viscosity attainable and may be orders of magnitude lower than η 0, depending on the degree of shear thinning. Viscosity is plotted against shear rate in a log(η) vs. log( γ ˙ {\displaystyle {\dot {\gamma }}} ) plot, where the linear region is the shear-thinning regime and can be expressed using the ...
The viscosity of a shear thickening – i.e. dilatant – fluid appears to increase when the shear rate increases. Corn starch suspended in water ("oobleck", see below ) is a common example: when stirred slowly it looks milky, when stirred vigorously it feels like a very viscous liquid.
At temperatures above the lambda point, helium exists as a liquid exhibiting normal fluid dynamic behavior. Once it is cooled to below 2.2K it begins to exhibit quantum behavior. For example, at the lambda point there is a sharp increase in heat capacity, as it is continued to be cooled, the heat capacity begins to decrease with temperature. [ 14 ]
The dilute gas viscosity contribution to the total viscosity of a fluid will only be important when predicting the viscosity of vapors at low pressures or the viscosity of dense fluids at high temperatures. The viscosity model for dilute gas, that is shown above, is widely used throughout the industry and applied science communities.