thank you Dr Amine. I just have 2 questions :
1/if i want to do them separately in one session(non conformal mesh), is it possible to put different element size in each part because i tried to change it and it changed for both of them.
2/in one session also,for a conformal mesh so conformal interface(by putting them in one part in design modeler ), should i use the same shape of mesh (tetra for both of them for example) or i can make tetra for the block and hex for the tubes ? and when i want to do a refinement on some curvatures on the surfaces of the tube should i make the same for the block at the same curvature (interface) when i'm working with conformal mesh?
thank you