Search results
Results From The WOW.Com Content Network
Ketchup is a shear-thinning material, viscous when at rest, but flowing at speed when agitated by squeezing, shaking, or striking the bottle. [11] Whipped cream is also a shear-thinning material. [6] When whipped cream is sprayed out of its canister, it flows out smoothly from the nozzle due to the low viscosity at high flow rate.
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). They then take a fixed time to return to a more viscous state. [1]
Plot of shear rate as a function of the shear stress. Dilatants in green. A dilatant (/ d aɪ ˈ l eɪ t ə n t /, / d ɪ-/) (also termed shear thickening [1]) material is one in which viscosity increases with the rate of shear strain. Such a shear thickening fluid, also known by the initialism STF, is an example of a non-Newtonian fluid.
In a Newtonian fluid, the relation between the shear stress and the shear rate is linear, passing through the origin, the constant of proportionality being the coefficient of viscosity. In a non-Newtonian fluid, the relation between the shear stress and the shear rate is different. The fluid can even exhibit time-dependent viscosity. Therefore ...
The viscosity of xanthan gum solutions decreases with higher shear rates. This is called shear thinning or pseudoplasticity. This means that a product subjected to shear, whether from mixing, shaking or chewing, will thin. This is similar to the behaviour of tomato ketchup. When the shear forces are removed, the food will thicken again.
Nonlinear viscoelasticity also elucidates observed phenomena such as normal stresses, shear thinning, and extensional thickening in viscoelastic fluids. [ 3 ] An anelastic material is a special case of a viscoelastic material: an anelastic material will fully recover to its original state on the removal of load.
A common feature of greases is that they possess high initial viscosities, which upon the application of shear, drop to give the effect of an oil-lubricated bearing of approximately the same viscosity as the base oil used in the grease. This change in viscosity is called shear thinning. Grease is sometimes used to describe lubricating materials ...
Figure 1. Bingham Plastic flow as described by Bingham. Figure 1 shows a graph of the behaviour of an ordinary viscous (or Newtonian) fluid in red, for example in a pipe. If the pressure at one end of a pipe is increased this produces a stress on the fluid tending to make it move (called the shear stress) and the volumetric flow rate increases proportionally.