Keyur Kanade
Ansys Employee

Viscosity is the measure of the fluid resistance to deformation. When fluids move they tend to deform continuously. This is due to some internal forces (or better stresses) that we can call shear stresses. For some fluids, the deformation is proportional to the magnitude of the shear stresses. These fluids are known as 'Newtonian Fluids'. The SI units of viscosity are kg / (m s) or (Pa s).

Have a look at our Ansys Innovation Courses. In particular you check out these two courses that discuss about viscosity:

What Are Fluids? | Ansys Innovation Courses
What are fluids? Get the answer in this free course by examining the physical properties of fluids and defining the many types of fluid flows.

Exploring the Physics of Drag | Ansys Innovation Courses
This fun and engaging course will teach you about the basics of aerodynamics, the phenomenon known as drag, and how airplanes stay up in the air.