What is the role of fluid viscosity in fluid flow?

Fluid viscosity affects fluid flow by creating resistance to motion and determining the fluid's ability to deform.

Viscosity is a measure of a fluid's resistance to flow. The higher the viscosity, the more resistant the fluid is to motion. This resistance creates frictional forces within the fluid, which can slow down fluid flow. Viscosity also affects the laminar or turbulent nature of fluid flow. In laminar flow, fluid particles move in parallel layers, while in turbulent flow, fluid particles mix chaotically. Viscosity can determine whether fluid flow is laminar or turbulent.

In addition to affecting fluid flow, viscosity also determines a fluid's ability to deform. A fluid with high viscosity is more resistant to deformation than a fluid with low viscosity. This means that a fluid with high viscosity will be more difficult to stir or mix, while a fluid with low viscosity will be easier to stir or mix.

Understanding the role of viscosity in fluid flow is important in many areas of physics, including fluid dynamics, aerodynamics, and hydrodynamics. By analysing the effects of viscosity on fluid flow, scientists and engineers can design more efficient systems for a wide range of applications, from aircraft design to oil drilling.