Sample profiles of surface shear stress against u for
Re= 1.0, Pr = 1.0 and S(u)= Cos(u) are shown in Fig. 11,
for selected values of viscosity-variation parameter and Reynolds
numbers. The increase in Reynolds Number and
decrease in viscosity-variation parameter increase the wall
shear-stress in u direction and on the other hand cause the
value of fluid velocity in this direction to approach its value
in inviscid flow, rapidly. In fact the increase in Reynolds number
and decrease in viscosity-variation parameter decrease the
thickness of the boundary layer.