Chapter 2, Problem 2.1PP

Define shear stress as it applies to a moving fluid.

To determine

Shear stress as it applies to a moving fluid.

Explanation of Solution

Shear pressure is most ordinarily connected to solids. Shear powers acting extraneously to a surface of a strong body cause disfigurement. As opposed to solids that can oppose miss happening, fluids do not have this capacity, and stream under the activity of the power. At the point when the liquid is in movement, shear stresses are created because of the particles in the liquid moving in respect to each other.

For a liquid streaming in a pipe, liquid speed will be zero at the pipe divider. Speed will increase while moving towards the focal point of the pipe. Shear powers are regularly present on the grounds that adjoining layers of the liquid move with various speeds contrast with one another.

By thinking about the speed of this relative movement, shear rate, $\gamma$, can be determined. Shear rate is characterized as a proportion of the degree or rate of relative movement between nearby layers of the moving liquid. Shear rate for the liquid streaming between two parallel plates, one moving at a consistent speed, and one is stationary is controlled by:

   $\gamma =\frac{u}{y}$

Where, $\frac{u}{y}$ is the velocity gradient and can be written in the differential form as $\frac{du}{dy}$