ESDU 91025:2011

$163.80

Non-Newtonian Fluids: Frictional Pressure Loss Prediction for Fully-Developed Flow in Straight Pipes

Published By	Publication Date	Number of Pages
ESDU	2011-06	NA

Guaranteed Safe Checkout

Category: ESDU

If you have any questions, feel free to reach out to our online customer service team by clicking on the bottom right corner. We’re here to assist you 24/7.
Email:[email protected]

Description

ESDU 91025 discusses models used to describe the rheology of
time independent pseudohomogeneous non-Newtonian fluids (power-
law, Bingham, Herschel-Bulkley and a generalised model due to
Metzner and Reed); they are used to calculate the laminar flow
pressure drop (which is independent of pipe roughness in this
regime). Values of generalised critical Reynolds numbers are
suggested to define transitional and turbulent flow. For turbulent
flow in smooth pipes, pressure loss is estimated on the basis of an
experimentally determined flow curve using either the Dodge-Metzner
or Bowen approach depending on the available measurements. Bowen
requires results for at least two pipe diameters. The choice of
Dodge-Metzner when data are limited is discussed; seven possible
methods are assessed against five sets of experimental results
drawn from the literature. While it is suggested that transitional
flows should be avoided, if the regime is required the use of a
turbulent correlation is recommended because it will yield an
overestimate. Suggestions are made for the treatment of roughness
effects. Several worked examples illustrate the use of the methods.
Six additional estimation methods are provided for cases where the
flow curve has a complicated form that cannot be fitted to any of
the rheological models. Guidance on the experimental determination
of rheological data and the calculation of the flow curve is given
in ESDU 95012. Two programs are provided as executable files and
within ESDUview: ESDUpac A9125 implements the Dodge-Metzner method
and ESDUpac B9125 implements the method of Bowen.