CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Dynamic mesh viscosity ratio limitation problem

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 20, 2021, 05:23
Default Dynamic mesh viscosity ratio limitation problem
  #1
New Member
 
Join Date: Mar 2021
Posts: 18
Rep Power: 5
jojoFD is on a distinguished road
Hi,

I am simulating a closed tank of air at 200 bar pressure and 293K temperature with a small cylinder moving inside at a velocity 1m/s, using a dynamic mesh (smoothing diffusion and remeshing method).

At 1 atm pressure, my case works fine. But at 200 bar, I get a "turbulent viscosity limited to viscosity ratio of 1.000000e+05 in (a lot of) cells" warning that won't go away for the whole simulation, which is making me doubt the physics of my results. The Reynolds number is about 2e6 so highly turbulent.

I read a lot on the subject so here are a few infos:
- my mesh quality is normally not the problem
- there is no inlet boundary condition values for turbulence to correct as my domain is fully closed
- I use a coupled scheme with second order scheme
- I reduced my under relaxation factors to 0.6, and set a low turbulence intensity (0.01) and viscosity ratio (2) for the initialization as the fluid is starting the simulation fully at rest.
- I am using a k-omega SSt model with TKE outer : 1.176 / inner 1 and SDR inner 2 / outer 1.168.

I really don't know what else to do/change so if you have an idea, that would be awesome

Thanks a lot
jojoFD is offline   Reply With Quote

Reply

Tags
dynamic-mesh, k-w sst, pressure, viscosity ratio

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
decomposePar problem: Cell 0contains face labels out of range vaina74 OpenFOAM Pre-Processing 37 July 20, 2020 05:38
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
spring-based dynamic mesh problem uhhaha2157 FLUENT 0 January 1, 2014 07:38
[ANSYS Meshing] dynamic mesh problem colopolo ANSYS Meshing & Geometry 8 August 16, 2011 18:26
[mesh manipulation] Dynamic Mesh Diffusivity Problem dancfd OpenFOAM Meshing & Mesh Conversion 0 August 29, 2010 11:50


All times are GMT -4. The time now is 07:56.