algorithm to find boundary and wall cells
 

Hello Everybody
Guys could you please help me with the algorithm to separate the wall and boundary cells. How would the program decide whether a cell is on the wall or the boundary?

Need help !


Shah

Do you mean internal walls and boundaries that are present in some form of bounding box?

Is the question perhaps related to reading CAD geometry?

Please provide more information.

Of course ! Reading the CAD geometry. For example if airfoil were to be the wall where the wall cells surround it, and at the far field being the boun dary cells. If we only have the cell and node data , how would we sort out cells based on their location.

Shah

I would try to flag the nodes on various boundaries and use that marker to structure the domain.

If you only have cell and node data then I imagine that it is difficult since you are trying to impose conditions not defined during geometry creation. I imagine the problem is not finding surface nodes, but rather to distinguish between the exterior boundary and the interior ones. If you assume that the exterior boundary has a certain structure (e.g. a box or a sphere) then you could check for that structure. If you like to have an efficient sorting/searching algorithm then the book by Löhner is a good starting point.

http://eu.wiley.com/WileyCDA/WileyTi...ctCd-EE33.html

so you mean to say, It is for the grid generator to tell based on CAD geometry , as to where the cells are located i.e. wall, inner ones, boundary etc.
Thank you very much for clarifying. It helped me def.