Hi! everyone.

I am in developing a 2D FDM flow solver with multi-block grid capability. serially-linked or parallelly-link grids are solved with no difficulties.

But for grids with singularity, like backward-facing step cornder, I have a problem to appose boundary condtition at corner points.

I wrote a code that one boundary condition imposed at one boundary. And used ghost cell to interchage block-to-block information.

So, if backward-facing step problem is considered, I use 3-blocks grid. hence, there is one singularity corner point..... see the fllowing fig.

-----------------------------

1 | 2

| ------ (1)-------------------

| 3

|-----------------------

i meshed the problem like above fig. for block1,3, no-slip bc imposed at point (1). but, I don't know what bc is implemented at point (1) for block 2 computation.

please, give me a change to see the world of CFD..... thanks in advance.

Dear Hyun,

If I understand your prob. correctly, pl. do the following. First look at the figure:

~~~~~[1]~~~~~[2~~~~~Z~~~~~2]~~~~~[3]~~~~~

Take the blocks in this manner and I hope "ghosts" will not trouble you!! I mean, make the corners or step, represented by "Z", internal part of the block [2]. Which means, corners you will be handling in the same manner as we do in a single block grid. Kindly correct me if I am wrong. It was difficult to draw a good figure. I could not understand yours figure also!!!

GS