Nonnegative rank (linear algebra)

29 yr old Orthopaedic Surgeon Grippo from Saint-Paul, spends time with interests including model railways, top property developers in singapore developers in singapore and dolls. Finished a cruise ship experience that included passing by Runic Stones and Church.

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

This parameter is often used for characterizing polymer solutions.

Extensional viscosity can be measured using rheometers that apply extensional stress. Acoustic rheometer is one example of such devices.

${\eta }_e=\frac{{\sigma }_n}{\dot{\epsilon }}$

where

${\eta }_e$ is the extensional viscosity or elongational viscosity

${\sigma }_n$ is the normal stress: ${\sigma }_n=\frac{F}{A}$

$\dot{\epsilon }$ is the rate of strain: $\dot{\epsilon }=\frac{1}{L}\frac{dL}{dt}$

For a Newtonian Fluid, the elongational viscosity is three times the shear viscosity which can be derived using the continuity equation for incompressible fluids.

${\eta }_e=3\eta$

References

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

See also

• Rheology
• Viscosity
• Trouton's ratio

Template:Fluiddynamics-stub