DEFINE VISCOSITY

Viscous mainly highlights the opposition to the flow where the reciprocal of the term is also termed as fluidity, which is the calculation of flow ease. It is also determined as one of the crucial factors in order to demonstrate the external forces that are necessary to get resolved when fluids are utilized in “the lubrication” and then it is shifted in pipelines. There are mainly two types of viscosity, such as “Kinematic” viscosity and “Dynamic” viscosity. “Kinematic Viscosity (ν) = μ/ρ” is the formula of “Kinematic” viscosity, and “Dynamic viscosity (μ) = τ/γ” where τ is shear stress and γ is shear strain rate   the formula of “Dynamic” viscosity.

Concept of viscosity and viscous

Viscosity is mentioned as the resistance of the gas or liquid to a transformation in the movement or shape of the neighbouring portions that are related to the other. Viscous is the noun form of viscosity that demonstrates the thickness or the calculation of the force that is tending to let the flow of the fluid. Viscosity reflects the opposition to the flow where the reciprocal of the term is also termed as fluidity, which is the calculation of flow ease. Consider the instance of molasses, which possess higher viscosity as compared to the water. It is because the fluid part is forced to shift along to particular extent parts that are adjacent. In this context, viscosity or Viscous can be regarded as the internal friction between the molecules. Viscosity is regarded as the crucial factor in demonstrating the forces that are needed to get resolved when fluids are utilised in “lubrication” and then it is shifted in pipelines.

Viscosity theory

• Molecular theory

The molecular theory is mentioned as one of the theories of viscosity that has attempted to correlate with the major two factors. The first factor is known as the segregation of the nearest molecules that are surrounded by provided molecules whereas the other possesses the potential of intermolecular between the molecules pairs. The tiny molecules in the fluid are gradually coupled to the other by the attraction of intermolecular. Hence, every molecule has the tendency to drag each other due to the attraction intermolecular if the two adjacent fluid layers move with distinct velocities. Due to this factor, the drag is going to dissipate the gradient of velocity within the liquid. Because of the exertion of drag on the other by molecules in fluid layers that are rotating with distinct velocities, the structure of molecules of the fluid is easily deformed.

• Rate process theory

It is one of the theories of Viscosity or Viscous, which is the same and very familiar rate theory that helps in governing the chemical kinetic reactions. The main component of this theory is that the molecule has to go through the potential obstruction in terms of flowing. According to this theory, the major consequence is the identification that liquid viscosity is demonstrated by the concentration of the molecule in the walls of shallow potential energy from where the molecules are activated and preferentially recruited.

Types of viscosity

Kinematic and Dynamic are the types of viscosity that help in calculating the propensity of the fluid to flow. Kinematic viscosity is mentioned as the connection between internal forces and viscous in the fluid. This type of viscosity calculates the ratio of the force of viscosity that is analogous to the diffusivity of the heat and mass and the momentum diffusivity. On the other hand, dynamic viscosity is referred to as the connection between “shear rate” and “shear stress “in the fluid. Both the types of viscosity are different from the parts as Kinematic viscosity helps in calculating the velocity whereas dynamic viscosity is the calculation of force. Formulas of both types are mentioned below:

“Dynamic viscosity (μ) = τ/γ”

“Kinematic Viscosity (ν) = μ/ρ”

Conclusion

Viscosity is determined as the internal friction among the molecules of a material. There are two important theories of viscosity such as the molecular theory and rate process theory. The dynamic viscosity is referred to as the resistance state to the movement of a single fluid layer over another fluid layer, and the “dynamic viscosity” formula can be denoted as “Dynamic viscosity (μ) = τ/γ”. Kinematic viscosity is mentioned as the connection between internal forces and viscosity in the fluid, and its formula can be written as “Kinematic Viscosity (ν) = μ/ρ”.