viskoossusel

Viskoossus is a term that refers to the resistance of a fluid to flow. It is a measure of the internal friction within a fluid. Imagine trying to pour honey versus trying to pour water. Honey is much more viscous than water because its molecules are more attracted to each other, creating greater resistance to movement. This resistance arises from the cohesive forces between molecules and the transfer of momentum between adjacent layers of the fluid when they are in motion relative to each other. High viscosity fluids flow slowly, while low viscosity fluids flow easily.

The SI unit for dynamic viscosity is the Pascal-second (Pa·s). Another commonly used unit is the poise (P), where 1 Pa·s = 10 P. Kinematic viscosity, which is dynamic viscosity divided by density, measures how easily a fluid flows under gravity. Its SI unit is square meters per second (m²/s), and the corresponding non-SI unit is the stokes (St). Temperature significantly affects viscosity; for most liquids, viscosity decreases as temperature increases, while for gases, it generally increases with temperature. Viscosity is a critical property in many scientific and engineering applications, influencing processes like pumping, mixing, and lubrication.