OVERVIEW Viscosity is a principal parameter when any flow measurements of fluids, such as liquids, semi-solids, gases and even solids are made. Brookfield. Centipoise (cP) is commonly used to describe dynamic viscosity because water at a temperature of 20°C has a viscosity of Centipoise. Learn about the formula for viscosity, Newtonian and Non-Newtonian fluids, how viscosity is measured, and what materials or products can use viscosity testing.


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This value is equal to the viscosity of the fluid.

Viscous Fluids - Lesson - TeachEngineering

Looking at the resulting diagrams, engineers can identify four fluid behaviors: Bingham plastic, Newtonian, shear thinning, and shear thickening see Figure 3. Representative curves are shown for Bingham plastic, Newtonian, shear thinning and shear thickening fluids.

Because the particles in these materials have weak bonds, at high stresses they break, causing them to flow and be characterized viscosity of fluids fluids.

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When the stress is relieved, the bonds form again, characterizing the materials as viscosity of fluids. Two material properties are needed to describe this material: The slope of the shear stress-rate of shearing strain diagram is the viscosity as described above and the intersection of the y-axis shear stress axis is the yield stress.

The yield stress defines the transition point between solid and liquid.

Fluid Viscosity Properties, including Dynamic Viscosity, Absolute Viscosity and Kinematic Viscosity

A common example of this fluid type is toothpaste. Newtonian fluids are identified by linear plots viscosity of fluids the diagram, which means that these fluids have constant viscosities that viscosity of fluids independent of velocity rate of shear.

Regardless of how fast or slow you stir these liquids, they always require the same proportional forces.

Everyday examples of this fluid type include: A range of fluid behavior examples: As you stir this type of fluid faster, it becomes much easier to stir.

While scientists do not viscosity of fluids understand the cause of this phenomenon, engineers have used fluids with this behavior to their advantage. For example, paint is a shear thinning fluid.


It is easy to adhere on a roller because of the increase in velocity the roller imposes on the fluid. However, once the paint is applied to the wall and the viscosity of fluids on the fluid is reduced, the viscosity increases to its original state and the paint stays on the wall without dripping.

Another example is whipped cream. Engineers used its characteristics to their advantage when designing pressurized can containers for easy dispensing of whipped cream.

When a force is applied to this fluid, its viscosity decreases and it flows smoothly like a liquid out of the nozzle. Once it comes to a rest on your tasty treat, it becomes rigid again increased viscositylike a solid. Additional common examples include ketchup, blood and motor oil.


For shear thickening materials, viscosity increases as velocity rate of shear increases. As you stir this type of fluid faster, it becomes much harder viscosity of fluids stir.

Fluid Viscosity Properties

This is due to closely packed particles combined with just enough fluid to fill the spaces between them. At low velocities, the fluid dominates the behavior and is able to continue to adequately fill the spaces between the particles because they are not moving viscosity of fluids.

At high velocities, the fluid cannot keep up with the particle movement and is unable to fill the spaces between them, so the particles viscosity of fluids rub against each other creating friction between them.

Engineers have also used this phenomenon to improve our lives. One example is body armor.