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

Need assistance in BC's for simulation of Vacuum cleaning nozzle

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 22, 2009, 14:56
Default Need assistance in BC's for simulation of Vacuum cleaning nozzle
  #1
Member
 
bruce
Join Date: May 2009
Location: Germany
Posts: 42
Rep Power: 16
bruce is on a distinguished road
Hello All

I am simulating vacuum cleaning nozzle (only half model) with density at inlet 25 degree Celsius, 70 litre/s fluid flow and outlet Pressure boundary.!

Here is my problem setup,

MESH:

Generated mesh in SnappyHexMesh-1.5.x
2.4 million cells


0/U:

....

inlet
{
type flowRateInletVelocity;
flowRate 0.07;
value uniform (0 0 0);
}

outlet
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}
symmetry
{
type symmetryPlane;
}


0/p:

....


outlet
{
type fixedValue;
value uniform 0;
}

inlet
{
type zeroGradient;
}

symmetry
{
type symmetryPlane;
}

But for some reason U & p getting exploding after 5-10 iterations.

PS:
-I have 1.5mm gap between the floor and the vacuum cleaning nozzle, is that the reason?

-Based on the outlet boundary area, i calculated the outlet velocity it comes to around 100m/s, is that realistic? is that the reason for divergence? it could be more near the nozzles and floor!!!

-I am using kEpsilon turbulence model with inlet k=0.0026 & epsilon=0.0002

Can anybody suggest me what is wrong, with the simulation. I will be glad to provide all information if necessary.

Thanks & kind Regards
bruce 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
subsonic nozzle flow, inlet-outlet BCs felix Main CFD Forum 3 May 15, 2006 11:37
compressible flow in a counterflow nozzle d.vamsidhar FLUENT 0 November 24, 2005 02:45
Need Assistance: BCs for k-e model implementation Dean Schrage Main CFD Forum 3 August 11, 2001 02:02


All times are GMT -4. The time now is 06:46.