ARE VISCOUS STRESS IS SHEAR STRESS OR NOT?

Question

I am talking about fluid flow with respect to friction behaviour for fluids.

Answer 1

Yeah, "shear stress" (taw :T ) is sometimes referred to as "viscous stress" both are one parameter.

However, "viscosity"  ( meu : u ) is a separate parameter, it is related the shear stess as in the realtion :

shear stress ( or viscous stress) = viscosity * velocity gradient

                                       T       =       u     *    ( dv / dy )

where,

shear stress ( or viscous stress) : T

viscosity : u

velocity gradient : ( dv / dy ) = change in velocity with elevation of fluid.

.

Answer 2

Yes. It is a shear stress