Non-Newtonian Fluids

Non-Newtonian Flow

Goals

Describe key differences between a Newtonian and non-Newtonian fluid

Identify examples of Bingham plastics (BP) and power law (PL) fluids

Write basic equations describing shear stress and velocities of non-Newtonian fluids

Calculate frictional losses in a non-Newtonian flow system

Non-Newtonian Fluids

η – Apparent Viscosity

Non-Newtonian Fluids

Modeling Power Law Fluids

Modeling Bingham Plastics

Frictional Losses
Non-Newtonian Fluids

Laminar Flow

MEB (contd)

Momentum Balance

Power Law Fluid

Velocity Profile of Power Law Fluid
Circular Conduit

Power Law (contd)

Laminar Flow Friction Factor
Power Law Fluid

Turbulent Flow Friction Factor
Power Law Fluid (Smooth Pipe)

Power Law Fluid Example

A coal slurry is to be transported by horizontal pipeline. It has been determined that the slurry may be described by the power law model with a flow index of 0.4, an apparent viscosity of 50 cP at a shear rate of 100 /s, and a density of 90 lb/ft3. What horsepower would be required to pump the slurry at a rate of 900 GPM through an 8 in. Schedule 40 pipe that is 50 miles long ?

Friction Factor (Power Law Fluid)

Bingham Plastics

Bingham Plastics

Laminar Bingham Plastic Flow

Turbulent Bingham Plastic Flow

Drilling Rig Fundamentals

Bingham Plastic Example

Drilling mud has to be pumped down into an oil well that is 8000 ft deep. The mud is to be pumped at a rate of 50 GPM to the bottom of the well and back to the surface through a pipe having an effective diameter of 4 in. The pressure at the bottom of the well is 4500 psi.  What pump head is required to pump the mud to the bottom of the drill string ? The drilling mud has the properties of a Bingham plastic with a yield stress of 100 dyn/cm2, a limiting (plastic) viscosity of 35 cP, and a density of 1.2 g/cm3.

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