Abstract:

ESDU 04005 is one of a group on the flow characteristics of non-Newtonian fluids. It contains a practical worked example that illustrates how to obtain, using a laboratory-scale tube viscometer, the relevant viscometric data necessary for frictional pressure loss estimation for full-scale pipeflow. Tube viscometers are the most reliable and widely used viscometric geometry.

The full range of tube viscometers is described in companion Data Item ESDU 95012, which also provides background guidance on non-Newtonian flow characterisation and viscometer selection. The behaviour of a flowing fluid can be characterised by its flow curve, which applies to the particular fluid in a particular state. The purpose of this Data Item is to guide the user, by way of example, through the various procedures needed to obtain the flow curve. These procedures ensure that the experimental data are corrected for end effects and wall slip whilst ensuring the viscometric data are obtained under laminar flow and isothermal conditions.

The methods of this Item are applicable to isothermal, fully-developed flow through straight pipes of circular cross-section, where flow properties are measured under steady-state shear conditions. These conditions are necessary in order to develop the flow curve, which can then be used to predict full-scale flow pressure drops in such fluids using the methods of ESDU 91025.