Having a difficulty in mergeing hexa-tetra
 

What I'm doing is to create tetra and hexa grids on each side of interface and merge them.

As many beside Simon said, I have exactly same interface from each side and have them in a single part, and use merge function in 'Edit Mesh - Merge nodes'.
After that, having both volume mesh in a part, I delete interface shell.

Sometime it does work, but for many times, it doesn't.

What I mean by 'doesn't work' is that, program prints 'could not include quad' and whenever I see that message, 'check mesh' finds 'Uncovered face', which means that I'm not supposed to delete the shell for that element.

What I do for this problem is just to guess the right ratio for hexa- tetra (I saw another post where Simon said 1.3:1 is the best for hexa-tetra) but for most times, it does reveal problems.


To deal with these 'Uncovered face' problem, I tried repair mesh functions, but they didn't work well.



My question is, is there any way I can have merged hexa-tetra mesh without 'uncovered mesh' problem?
I'm tired of doing 'try and error'.

Any suggestion will be appreciated..

you don't delete anything when you merge, why you want to delete ??

after merging
 

After merging hexa-tetra, you put both sides' domains in a part and delete shell to eliminate the wall between them, that's what I know so from threads here.

That's what I did, but sometimes it doesn't work that was my question.

But I somehow realized that putting both domains in a part to have a single domain and then deleting shell solve the above problem most times right after posting this thread. So, this seems no more of problem to me for now.

Thank you for your reply anyway. :)

just declare that as interior in the boundary condition setup !