BAKER HUGHES - Drilling Fluids Reference Manual

Baker Hughes Drilling Fluids
Figure 1-4
Two Dimensional Velocity Profiles of Laminar Flow for a Non-Newtonian Fluid
The two dimensional velocity profile of a non-Newtonian fluid in laminar flow depends upon the
relationship between the shear stress and shear rate. Several examples of the velocity profile are
shown in Figure 1-4.
Turbulent Flow
Turbulent flow occurs when a fluid is subject to random, chaotic shearing motions that result in local
fluctuations of velocity and direction, while maintaining a mean velocity parallel to the direction of
flow. Only near the walls does a thin layer of orderly shear exist. Thus the velocity profile is very
steep near the walls, but essentially flat elsewhere as shown in Figure 1-5.
Transitional Flow
Transitional flow occurs when the flow of a fluid is neither completely laminar nor completely
turbulent. In other words, there is no abrupt transition from one flow regime to another.
Figure 1-5
Two-Dimensional Velocity Profile of Turbulent Flow in a Pipe for a Newtonian Fluid
Baker Hughes Drilling Fluids
Reference Manual
Revised 2006 1-9