Finite elements size control in PDE Tollbox

Hi

How can I set size of finite elements of the mesh having 2D geometry from edges? I know that I can set maximum size of elements in the mesh but I want to set very small size of elements matched to chosen edge from the geometry and much bigger size for further ones.

My first idea is to generate geometry consisted of high number of very short sections for chosen edges - elements of generated mesh should not be bigger than this sections.

Second idea is to divide domain of solution into areas and for each one generate mesh with different element size limits.

Does exist better way to generate mesh with high density of points in chosen areas (near to chosen edges) and with small density in other places? If not, which method of above ones needs less computational effort (in runned simulation).

Best regards

Mariusz

[Ekaterina Startseva]

Hi,

Did you solve this problem? I'm searching the way to control size of finite elements along the given axis of symmetry.

Ekaterina

[ADSW121365]

If you're using the generatemesh function or the 2D PDE Tool, I believe the mesh generation is limited to a graduation of 2 across the mesh, but you can vary it between 1 and 2 to have some control.

Your best approach - thought it will involve a learning curve - would probably be an external mesh generator. There are a bunch of free open-source meshers, my preference is gmsh. Depending on your geometry, there are numerous ways to controll mesh size in different regions from specifying specific element sizes at points, to fine boundary layers near domain-transitions etc.

GMSH comes with the added bonus of built in mesh-optimisation libraries which refine and optimise your FEM mesh vs MATLABs generate mesh which essentially just fills the region with elements.