Shear flow
= Shear flow
A <shear flow> has a <velocity field> varying across adjacent <fluid> layers, giving a nonzero <shear rate>. A parallel example is $\mathbf u=U(z)\mathbf e_x$, with <vertical shear> $U'$. <Linear shear flow> has constant shear, while a <shear layer> concentrates the <velocity> change in a narrow region.