GiD forum

Hi,

I read in the help document that the mesh size (as it is shown in Mesh->Draw->Sizes) is defined as the average edge length. I am performing adaptive mesh refinement using GiD background meshes and would like to make sure I have the exact definition since I need to recalculate mesh sizes in kratos.

For the example of a triangle with edge lengths l1,l2,l3 is it

(l1 + l2 + l3) / 3 ?

Or

sqrt[ (l1*l1 + l2*l2 + l3*l3) / 3 ] ?

Thank you

The meaning of the sentence 'the mesh size is an averaged edge lenght' must not be considered strictly mathematically.

This size represent the value of the edge size that the user wants for the next element to be generated, but probably won't be exactly reached.

For example with an 'advancing front meshing algorithm' the element (e.g a triangle) has a first staring boundary edge fixed, and to create the element only the new to edges are relatively free to be set by the mesher: growing or decreasing from the first edge size to try to be close to the 'user wanted size', but the change of edge size is limited by the 'unstructured size transitions' factor and other facts (other close nodes, etc.)

Thanks for your reply. I needed to compute the mesh size on an existing mesh, rescale it based on some solution information and then pass it to GiD via the background mesh feature to generate a new mesh. I was not concerned about GiD exactly satisfying my given mesh size, but rather that by using a slightly different definition of mesh size I would introduce some unwanted scaling effects. In any case, it seems to be working with the definition I have tested.

Thanks,
Mike