Newton's Law of Viscosity describes the relationship between the shear stress and the shear rate in a fluid. It holds for Newtonian fluids and implies that the fluid's viscosity remains constant regardless of the stress applied. This law is crucial in determining how fluids flow under various forces.
Definitions
Definitions
Transport Phenomenon
The study of the movement of mass, momentum, and energy in physical systems.
Brownian Motion
The erratic, random movement of microscopic particles in a fluid as a result of continuous bombardment from molecules of the surrounding medium.
Diffusion
The net movement of molecules or atoms from a region of high concentration to a region of low concentration.
Viscosity
A measure of a fluid's resistance to deformation or the internal friction within the fluid.
Newtonian Fluid
Fluids that have a constant viscosity and follow Newton's law of viscosity, where the shear stress is linearly proportional to the shear rate.
Section 1: Transport Phenomenon
Newton’s Law
Brownian Motion
Brownian motion is observed in small particles suspended in a fluid, where they exhibit random and unpredictable movements. This phenomenon is critical in understanding diffusion processes and is used in calculating the diffusion coefficient through the Stokes-Einstein formula.
Diffusion and Diffusion Coefficient
Diffusion is a fundamental transport mechanism, and the diffusion coefficient quantifies the rate at which diffusion occurs under a concentration gradient. It is influenced by the medium's temperature, the particles' size, and the interaction between the particles and the fluid.
Stokes-Einstein Formula
The Stokes-Einstein formula relates the diffusion coefficient to temperature and viscosity, providing insights into particle mobility in a fluid:...
