Shear-thinning liquids – as the shear strain rate decreases, it decreases.

Shear thickening liquids or dilatant – as shear strain rate increases, viscosity increases.Those fluids are termed non-Newtonian fluids. However, some fluids do not abide by this principle. Liquids like water and gases are considered Newtonian fluids because they are independent of strain rate. Measuring the resistance of the fluid passing through a medium when an external force is applied.Įven though it is not nature’s fundamental law, Newton’s laws describe and define the phenomenon and its related concepts. Measure the resistance of the flow of fluid on account of gravity or gravitational force. Other units include Pascal second (Pa-s) and newton-second per metre square (N s m⁻²). A high viscous fluid resists motion, while a low viscous fluid doesn’t. The resistance arises due to the internal friction between the fluid layers. It can be defined as a measure of a fluid’s resistance when it flows. On the contrary, low viscous fluid has fewer intermolecular forces, giving less internal friction for layers to slide past one another. A highly viscous fluid has greater intermolecular forces that give it a lot of internal friction for the layers to slide past one another. It arises due to the internal frictions between the two layers of the fluid when it flows.Ī fluid with an excellent viscosity can resist motion, while a fluid with a low viscosity can easily pass or seep through objects. It can also be thought of as a fluid’s resistance to objects or a measure of the fluid’s thickness when it passes through it. It arises due to the relative motions between two layers of that respective fluid. Fluids, when flowing, offer specific resistance or hindrance.

Viscosity definition