Understanding Viscosity: Newtonian Fluids

This lecture delves into the concept of viscosity, focusing on Newtonian fluids. The instructor explains how viscosity relates to shear stress and shear strain rate, introducing the idea of dynamic and kinematic viscosity. The discussion covers the no-slip condition, shear stress-strain rate relationship, and the distinction between Newtonian and non-Newtonian fluids. Various examples, such as cornstarch and paint, illustrate shear thickening and shear thinning behaviors. The lecture also touches on the compressibility of fluids, introducing the bulk modulus as a measure of compressibility. The importance of understanding these concepts for fluid dynamics and making simplifying assumptions is emphasized.