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beginner March 12, 2002 20:24

[basic question]
what is the Newtonian, and Non-Newtonian flow ?

Jonas Larsson March 13, 2002 04:36

Re: [basic question]
In a Newtonian fluid the shear stress is proportional to the velocity gradient (Tau = mu * du/dx, where mu is the viscosity). Most normal fluids are Newtoninan (air, water, ...)

In non-Newtonian flows this linear relation between stress and strain is not valid - for example, many paints become more "fluent" (less viscosity) under shear (when you paint) and then "stiffens" when the shear dissapears. Many polymer flows are also non-Newtonian, blood flows also. In non-Newtonian flows there is a non-linear relation between the stress and the strain (strain changes the viscosity)

Non-Newtoninan flows are often difficult to simulate.

mukhopadhyay March 13, 2002 23:22

Re: [basic question]
Jonas, I have a suggestion. We are to encourage beginners and also ensure that the right message goes. So, why not we suggest text books for such beginners in place of giving kind of brief answers (because of limited space availability, etc.). They will be really enlightened I do believe.

Jonas Larsson March 14, 2002 04:32

Re: [basic question]
Sure, you're free to suggest a good book instead.

mukhopadhyay March 14, 2002 05:15

Re: [basic question]
Boundary layer theory by H Schlichting and Transport phenomena by Bird, Stewart and Lightfoot

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