Shear stress and frictional drag on the plane immersed surface

1 Shear stress and frictional drag on the plane immersed surface 

As seen above, the shear stress in the fluid at the smface (y = 0) is given by  

Substitution for S from equation (7.17) and with slight re-arrangement  

Equation (7.21b) gives the local value of the shearing stress on the plate which can be averaged over the length of the plate to obtain a mean value, t  

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