Finite element method - number of elements

poornima

Hello,

I am using 2 dimensional finite element method to determine the temperature on a cylindrical wall in which fluid expands from inlet to outlet.

My solution is dependent on the number of grids (6-20). I understand that the accuracy of the solution depends on the number of grids, of course after a certain number the accuracy will not change.

But when i change the grids by 2 or 3, the solution is absurd, % error is more than 1000 sometimes.

How can I make my solution less sensitive on the number of grids?

Regards Poornima