What is Dynamic Viscosity?
Dynamic viscosity is a measure of molecular frictional resistance to flow of a fluid under some applied force. In the region of the fluid it can also be considered as the ratio of the stress to the mean rate of change of strain. The SI unit is pascal-seconds, so for a fluid of viscosity one pascal-second this means that in one second the fluid will move a distance equal to the thickness of the layer if it is placed between two plates and pushed by one plate sideways with a shear stress of one pascal. The viscosity of a fluid depends on the molecular forces or interactions between the different components of the mixture, and is a measure of the molecular transport or diffusion of momentum. Viscosity is high for fluids whose components have strong molecular interactions and is low if the molecular forces are weak. There are many factors which affect dynamic viscosity, including temperature. Usually an increase in temperature will result in a decrease in the viscosity and vice versa. Anot
