CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > ANSYS Meshing & Geometry

[ANSYS Meshing] Uneven mesh

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 24, 2016, 19:46
Default Uneven mesh
  #1
New Member
 
Antoine Aad
Join Date: Apr 2011
Posts: 7
Rep Power: 7
rocketeer is on a distinguished road
Hi!
I am simulating a non-premixed combustion with DPM on a rocket engine using Ansys fluent. I only enabled the flow and turbulence (in the solution controls), to simulate the cold flow before proceeding with the final simulation. The residuals (continuity, x,y and z) are fluctuating and nowhere near convergence.
I think I might have a problem with the mesh!
I have a negative pressure gradient on the throat as depicted in the figure below. So I am refining the mesh at the throat.
My problem is that I have an uneven mesh at the walls and at the exit of the geometry as shown in the figure below. So how can I solve this problem?
Attached Images
File Type: jpg Untitled.jpg (55.6 KB, 18 views)
File Type: jpg Untitled1.jpg (191.8 KB, 15 views)
rocketeer is offline   Reply With Quote

Old   February 25, 2016, 23:45
Default
  #2
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
This looks like a problem related to geometry . make sure you have a clean surface, no divided edge . can post a screenshot of your geometry . from desigbmodeler maybe?
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   February 26, 2016, 08:38
Default Geometry/DesignModeler
  #3
New Member
 
Antoine Aad
Join Date: Apr 2011
Posts: 7
Rep Power: 7
rocketeer is on a distinguished road
Here's the images showing the back and front of the rocket engine, and on the left (the details view) and the tree outline.
Is there something I should modify in the properties on the left pane?
Attached Images
File Type: jpg Untitled2.jpg (89.2 KB, 11 views)
File Type: jpg Untitled3.jpg (85.8 KB, 11 views)
rocketeer is offline   Reply With Quote

Old   February 26, 2016, 12:06
Default
  #4
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
can you try hexa mesh for this geometry?
Far is offline   Reply With Quote

Old   February 26, 2016, 13:07
Default tetrahedron mesh
  #5
New Member
 
Antoine Aad
Join Date: Apr 2011
Posts: 7
Rep Power: 7
rocketeer is on a distinguished road
I'm using a tetrahedron element with advanced size function of "proximity and curvature", and went up from 1,700,000 elements to 7,269,391 elements (in a 20 cm long geometry). Do you think that hexahedral mesh will solve the problem? take a look at the new mesh.
Attached Images
File Type: jpg Untitled4.jpg (177.8 KB, 5 views)
rocketeer is offline   Reply With Quote

Old   February 26, 2016, 13:24
Default
  #6
pkp
New Member
 
Presteina
Join Date: Feb 2016
Location: Canada
Posts: 16
Rep Power: 2
pkp is on a distinguished road
Hi,
Your works seems to be so good with DPM spray.
I am also working on DPM. Can you help me out with the Spray modeling in non premixed combustion model ?
I am not able to get the spray in the form of droplets which also interacts with the continuous.

Thanks a lot in advance.
pkp is offline   Reply With Quote

Reply

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
Star CCM Overset Mesh Error (Rotating Turbine) thezack CD-adapco 7 October 12, 2016 11:14
[ICEM] surface mesh merging problem everest ANSYS Meshing & Geometry 44 April 14, 2016 06:41
sliding mesh problem in CFX Saima CFX 45 September 22, 2015 10:53
[ICEM] Problem making structural mesh on a surface froztbear ANSYS Meshing & Geometry 1 November 10, 2011 09:52
snappyHexMesh won't work - zeros everywhere! sc298 OpenFOAM Native Meshers: snappyHexMesh and Others 2 March 27, 2011 21:11


All times are GMT -4. The time now is 18:18.