CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

DPMFoam Overestimates Turbulent Dissipation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 28, 2020, 07:55
Default DPMFoam Overestimates Turbulent Dissipation
  #1
Member
 
Sereff
Join Date: Jan 2019
Posts: 49
Rep Power: 7
Sereff is on a distinguished road
Hello everyone,

I was trying to evaluate the turbulence modulation of particles in boundary flow. Eveything runs smoothly for pimpleFoam and DPMFoam and I was able to get some interesting result. But then I tried to compare the result between pimpleFoam and DPMFoam without particle injection ( "active", "coupled", "transient" all set to "false;" in kinematicCloudProperties) just to prove the modulation was indeed due to the particle injection instead of different solver, thus making my concludion more robust. But I failed to do so. It seems that even without the particle injection, the turbulence in DPMFoam simulation was dissipated much faster than the turbulence in pimpleFoam.

Does anyone have some ideas? Thanks in advance for any suggestion.



Kind regards,
Sereff is offline   Reply With Quote

Old   April 28, 2020, 12:30
Default
  #2
HPE
Senior Member
 
HPE's Avatar
 
Herpes Free Engineer
Join Date: Sep 2019
Location: The Home Under The Ground with the Lost Boys
Posts: 931
Rep Power: 13
HPE is on a distinguished road
could you please refer to the link at the bottom, if possible?

thanks.
HPE is offline   Reply With Quote

Old   May 5, 2020, 08:58
Default
  #3
Member
 
Sereff
Join Date: Jan 2019
Posts: 49
Rep Power: 7
Sereff is on a distinguished road
after some digging. it seems to be caused by line 9, which increases the robustness of the solver while introducing extra diffusivity, of pEqn.H from DPMFoam:
Code:
    surfaceScalarField phiHbyA
    (
        "phiHbyA",
        (
           fvc::flux(HbyA)
         + alphacf*rAUcf*fvc::ddtCorr(Uc, phic) // <------- THIS LINE!
        )
    );
kind regards,
Sereff is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
CFX Treatment of Laminar and Turbulent Flows Jade M CFX 18 September 15, 2022 08:08
VISCOUS DISSIPATION ROBERT Main CFD Forum 30 May 29, 2019 05:21
Turbulent kinetic energy and energy dissipation at boundary mshotm2000 FLOW-3D 4 December 12, 2016 10:44
Value of Epsilon (turbulent dissipation)? Yuby OpenFOAM Pre-Processing 10 February 24, 2015 18:37
Turbulent dissipation rate in UDF John Deas FLUENT 0 February 20, 2009 13:27


All times are GMT -4. The time now is 12:33.