viscosity coefficient

Perzyna, in 1963, introduced a viscosity coefficient that is temperature and time dependent.

The viscosity coefficient is a property of a Newtonian material that, by definition, does not depend otherwise on or .

The volume viscosity coefficient is relevant when the fluid's compressibility cannot be ignored, such as in the case of ultrasound in water.

Maxwell's calculations show that the viscosity coefficient is proportional to the density, the mean free path, and the mean velocity of the atoms.

In this sense, solids undergoing plastic deformation is a fluid, although no viscosity coefficient is associated with this flow.

If there is a lack of equilibrium between these degrees of freedom, then the rate of equilibration will be determined by the rotational viscosity coefficient.

This modified form is not only more akin to the physics it represents but it also has the advantage of being dependent on only one viscosity coefficient.

Synovial fluid exhibits non-Newtonian flow characteristics; the viscosity coefficient is not a constant and the fluid is not linearly viscous.

For a given velocity u and viscosity coefficient , the general form of Burgers' equation (also known as viscous Burgers' equation) is:

Extensional viscosity (also known as elongational viscosity) is a viscosity coefficient when applied stress is extensional stress.

If the flow is homogeneous within the region, we can set the product of the vertical gradient of the mean horizontal flow and the eddy viscosity coefficient equal to :

A liquid, forced to flow in this way by a shearing force σ, experiences a viscous resistance expressed by where v is the velocity of flow along a tube of radius x, so that is the velocity gradient or shear rate γ, and η is the viscosity coefficient of the liquid.

In an isotropic Newtonian fluid, in particular, the viscous stress is a linear function of the rate of strain, defined by two coefficients, one relating to the expansion rate (the bulk viscosity coefficient) and one relating to the shear rate (the "ordinary" viscosity coefficient).