CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Non-Newtonaian Turbulent Flows

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   August 30, 2009, 15:46
Cool Non-Newtonaian Turbulent Flows
New Member
Robert Meroney
Join Date: Aug 2009
Posts: 2
Rep Power: 0
meroney is on a distinguished road
Fluent provides an option to solve various turbulence models while simultaneously specifying non-Newtonian fluid properties (Eg. power law, Carreau, Cross, Herschel-Bulkley, etc.). This model has recently been used to calculate flow around mixers in anaerobic digesters in the reviewed literature. I would like to convince myself that this is a viable model; hence, I have attempted to validate the protocol by reproducing various experimental and DNS data for non-Newtonian power law fluids flowing in pipes. The experimentalists report velocity profiles, turbulence components, pressure drops, shear, etc.

First, I succesfully reproduced Laufer's turbulent pipe flow Newtonian fluid data using the RMS model to convince myself I was using Fluent properly. Results were VERY good in all respects. Then I have attempted to replicate the DNS study by Rudman (2004) J. Non-Newtonian Fluid Mech, 118, pp 33-48 where they predicted velocities and turbulence using DNS and compared to shear-thinning CMC solution data. I used their specifications for viscous properties, RMS and ke-realizable models, very fine grids near the wall (similar to earlier Laufer y+~O(1)), and iterated to residuals below 10^-4.

The results produced too high pressure drops, too large wall shears, and inappropriate u', v', and w' behavior. I then attempted to replicate the laser-doppler measurements of Pinho and Whitelaw (1990), J. Non-Newtonian Fluid Mech, 34, 129-144. Results were similarly dismal.

Has anyone had a better experience? Can you share details? Can you suggest what my problem might be if you have had better success?

meroney is offline   Reply With Quote


non-newtonian, turbulent pipe flow

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
time step for turbulent flows vishnu FLUENT 0 December 13, 2006 02:28
Turbulent Decay in Strongly Accelerated Flows Jonas Larsson Main CFD Forum 3 April 29, 2003 06:32
About low Re number turbulent flows gorka Main CFD Forum 13 April 2, 2003 05:19
calculating recirculating turbulent flows with k-e Abhijeet Vaidya Main CFD Forum 10 November 18, 2002 09:21
CFD of turbulent flows raj calay Main CFD Forum 23 April 23, 1999 05:03

All times are GMT -4. The time now is 21:43.