CFD Online Logo CFD Online URL
Home > Forums > General Forums > Main CFD Forum

Issue with arbitrary Lagrangian-Eulerian method and mesh optimization

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

LinkBack Thread Tools Search this Thread Display Modes
Old   August 16, 2014, 16:50
Question Issue with arbitrary Lagrangian-Eulerian method and mesh optimization
New Member
Shing Chan
Join Date: Aug 2014
Posts: 1
Rep Power: 0
mikolchon is on a distinguished road
I hope someone can help me with this. I implemented a mesh optimizer following an Ansys paper "An Approach to Combined Laplacian and Optimization-Based Smoothing for Triangular, Quadrilateral, and Quad-Dominant Meshes (1998)" by Scott Canann, Joseph Tristano & Matt Staten. The optimizer works really well to correct any mesh. What I did next is to try to use it to correct the triangle deformations caused by the big displacements that happen in a moving body simulation with ALE method.

First of all, I'm new to CFD and I'm not sure if the optimizer is suitable for this task. From the paper it seems that it is meant to be used after mesh generation/remeshing only. But anyways, the implementation was done and it has an issue concerning the mesh velocity & displacement discontinuity that resulted from the optimizer corrections.

Given a displacement of the boundary points of the moving object, we propagate this displacement to the rest of the mesh points via spring analogy. This would naturally result in a smooth displacement field of the mesh, ranging from the displacements on the moving boundary to zero on the mesh fixed boundaries; and hence a smooth mesh velocity too. But when a triangle drops below a given quality tolerance, the optimizer is called and corrects the triangle (and maybe the neighboring triangles as well), messing up the smoothness of the mesh displacement & velocity field. Also, the correction displacements made by the optimizer are often too big compared to the average displacements (x10e5 ~ x10e7), which is good in terms of optimizing the mesh alone (it optimizes in few steps), but results in nodes with extremely high mesh velocities. One idea in mind is to adjust the step size so that the correction displacement has to be near the same size of the original displacement, but even though I'm not sure if this is the correct tool for the job. Any opinions are welcome. Thanks!
mikolchon is offline   Reply With Quote


ale, mesh optimization, smoothing

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
[ICEM] Problem with using the Delaunay volume mesh method manahara ANSYS Meshing & Geometry 12 December 25, 2014 22:54
Arbitrary Lagrangian-Eulerian (ALE) Method tikes Main CFD Forum 11 October 1, 2013 06:05
3D Hybrid Mesh Errors DarrenC ANSYS Meshing & Geometry 11 August 5, 2013 07:42
[snappyHexMesh] Layers:problem with curvature giulio.topazio OpenFOAM Meshing & Mesh Conversion 10 August 22, 2012 10:03
Icemcfd 11: Loss of mesh from surface mesh option? Joe CFX 2 March 26, 2007 19:10

All times are GMT -4. The time now is 14:13.