CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Mesh adaptation methodology (capturing the shock)

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 22, 2016, 02:48
Default Mesh adaptation methodology (capturing the shock)
  #1
Member
 
Join Date: Nov 2015
Posts: 57
Rep Power: 10
taillanm is on a distinguished road
Hello!
I am modeling a case of a sphere-cylinder body (like a bullet) (2D axissymmetric). My ultimate goal is to make studies about transition.

My case: Mach of 1.5, coupled flow, free stream inlet, pressure outlet. I have no problems about the physics (as I refined manually along the shock with volumetric controls and ran the case, no problems... very time consuming to make manual mesh controls for the shock)
I followed step by step the methodology to adapt (refine) my mesh ("automatically") near the shockwave in front of my body, from this tutorial: https://steve.cd-adapco.com/articles...pturing-shocks

But I didnt succeed..

My mesh settings: polygonal + prism layers (20, at 1e-6 first cell, 3mm thick) I am working with absolute values for mesh sizes. Default: Target surface size: 0.01m Minimum surface size: 1e-5m Surface growth rate: 1.2 I have one volumetric control to refine around my body (5e-3m).

My field functions:
0-CellWidth : pow(${Volume}, 1/3)
0-DenGrad : mag(grad(${Density}))*CellWidth
0-Refine : (${WallDistance} < 0.04) ? 0 : (${Dengrad} > 0.05) ? ${CellWidth}/2 : 0)


The condition of wall distance is there because density gradients are also present near the boundary layer and I don't need refinement there..
I checked while the simulation is running, the cells supposed to be divided by two in length are highlighted, but when I remesh (after extracting my table), the refinement doesn't appear..
Am I wrong somewhere.. ?
taillanm is offline   Reply With Quote

Old   May 3, 2016, 05:56
Default
  #2
Member
 
Join Date: Nov 2015
Posts: 57
Rep Power: 10
taillanm is on a distinguished road
the field function for the cell width is not valid, it should ressemble

some constant * pow(Volume/Position[1], (1/2))

but the problem still persists
taillanm is offline   Reply With Quote

Reply

Tags
field function refinement, mesh adaptation, shock

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
[snappyHexMesh] Add Mesh Layers doesnt work on the whole surface Kryo OpenFOAM Meshing & Mesh Conversion 13 February 17, 2022 07:34
Shock capturing in 2D/3D Abhishekd18 Main CFD Forum 2 June 27, 2014 11:42
[snappyHexMesh] Layers:problem with curvature giulio.topazio OpenFOAM Meshing & Mesh Conversion 10 August 22, 2012 09:03
[Gmsh] 2D Mesh Generation Tutorial for GMSH aeroslacker OpenFOAM Meshing & Mesh Conversion 12 January 19, 2012 03:52
Convergence moving mesh lr103476 OpenFOAM Running, Solving & CFD 30 November 19, 2007 14:09


All times are GMT -4. The time now is 21:28.