Number of cells

Christian Holm

I have been wondering. When do you know that your model has enough cells? I mean, I know that the solution should be "grid independent", but in praxis there are not always time to re-calculate the case with an increase in cells and if the model is large/complicated a restriction in cell number is sometimes required due to calculation time.

I know that if you are looking for separation, the cell-density near the walls should be dense, i.e. the number of cells should be increased in areas where you expect large gradients. BUT….. When do you know when there are enough cells.

Christian

(Maybe the answer is: "When the solution looks as expected" or "Judge independently from case to case based on the physical design and expected flow pattern").