wall shear stress
 

hi
I am trying to find the wall shear stress in a rectangular channel for the dimension 100mm*20mm (2D analysis) using wall flux then wall shear stress section in fluent.

Though ansys gives a result which when I try to validate analytically using the formula for shear stress between two parallel plates.

shear stress = (-1/2)*(del p / del x)*(t)

where
(del p / del x) is pressure variation along x direction i.e. the flow direction
and
t is the thickness of the channel

this does not give satisfactory results.

little help plz.

proficiency level - started a week back