Is is possible to create different element sizes in connected blocks?
 

If two blocks are stacked along x-axis and I want to give one block x divisions along y-axis and the other y, is it possible?
I have tried y as an integer multiple of x and it does not work. So is it not possible through blockMesh or are there methods to achieve so?

You need to make sure the two blocks are not automatically connected. Easiest way to do so is to define the shared points twice. now define an arbitrary mesh interface on the two shared faces.



The other option is to use stitchMesh after blockMesh. With option one you are interpolating from one block to the next, which leads to a (depending on setting maybe just slightly) lower accuracy. The other option creates triangles or wedges etc in between to connect them.


Otherwise there is no option to connect non matching cells.

There is another option, face merging. Again, you define block points twice, name both patches, then include them in mergePatchPairs. This is similar to stitchMesh.