open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,
I'm generating mesh over a 10m long channel. I tried creating a mesh with Default Edge Length 0.03m. When choosing Edge growth ratio, the default value is set to 1.2. The resultant mesh is shown in figure "mesh2". In this, when I measure the length of an element with ruler option, the length is around 0.03m. But, when I change the edge growth ratio to 1, the average edge length in the generated mesh becomes 0.1m when measured (figure "mesh1"). Could you please explain why this is happening?

Also, in mesh 2, why is there a mesh of different element size on the side as highlighted?

Many thanks!

Hello,
Edge growth ratio is the allowable proportion a mesh element can grow from its neighbor starting from the boundary. If the ratio is 1, it means elements are not allowed to grow and has no practical use.
Bear in mind that if elements do not need to grow (i.e. constant density) they won't, no matter how large the edge growth ratio is.
In your post, it is not clear what is you are trying to accomplish. If you elaborate, maybe we can provide more help.
Costas

Hi Costas,

Thanks for the clarification.

I want to generate a mesh with constant density and element size of 3cm in a 10m long channel. I tried generating the mesh with two values of edge growth ratio, as explained above, 1 and 1.2. I was not sure why there is difference in element size generated in the mesh with different edge growth ratio values as shown in the above two pictures.

Ananth.

Hi Ananth,
Setting 'Default Edge Length' = 0.03 should enough to accomplish your aim. Make sure you have not unchecked 'Resample Outline'.
You can also play with T3 Channel Mesher that will produce more appropriate meshes for channels, but your case is simple anyway.
Costas

Many thanks Costas! not unchecking 'Resample outline' solved this.