# Rate Of Shear

## Definition - What does Rate Of Shear mean?

Rate of Shear is the change of velocity when a fluid passes over adjacent layers. It is a simple test to check the viscometry of fluids. The velocity gradient is measured along the diameter of fluid flow channel. It can be calculated by the ratio of the velocity over distance. Apart from the viscosity of the substance, the Rate of Share is also dependent on the angular displacement of the material. However, when the Rate of Share of a cone is calculated it may increase if the gap between vertical lines begins to vary.

## Petropedia explains Rate Of Shear

Rate of Shear is of two types, i.e., constant shear rate and stepped shear rate. As it highly depends on viscosity thus its behavior fluctuates such that:

- If the viscosity increases, the Rate of Shear decreases
- If the viscosity decreases, the Rate of Shear increases
- If the viscosity remains constant, the Rate of Shear also remains constant

To portray the behavior of materials it forms four flow curves namely newtonian, shear thinning, shear thickening and bingham plastic. Moreover, when shear rate is multiplied with the viscosity it gives the value of shear stress. The units of Rate of Shear are denoted by the inverse of seconds.