Turbulent vs Laminar Flow. Flow velocity profile

Not all fluids particles travel at the same speed within a pipe. the shape of the velocity curve depends

wether the flow is laminar or turbulent.

If the flow is laminar, the shape is of the curve is parabolical with maximum velocity at the center, which is twice

the velocity of the pipe wall. the velocity of the wall almost is zero.

in turbulent flow, the entire fluid flows at a given velocity, without that parabolic shape, an the velocity is less 
than laminar flow in the same pipe diameter.

see the picture.