hi,I have an airfoil of chord 1 meter and a circle having a radius of 10 meters, but when I want to create a mesh for this face(circle-airfoil), gambit does not create a mesh completely, and I have some blank space in my mesh area, thus I have to decrease the ratio of the airfoil edge, and this causes inaccuracy in my solution, what should I do?

I remember having this problem some 5 or 6 years ago. I do not have gambit handy to confirm but I think there is a default for the max number of grid cells on one face. You can go to edit --> defaults and change that. The other solution ofcourse is to split your domain into more than one face and mesh the inner zone with a fine mesh and coarser for the outer since you don't really need a very fine mesh away. THis way you would have more control. Another way to do it would be to split your circle into 2 sections using edges that go out from your airfoil to the outer circle. Then mesh the edge with a gradually increasing progression. This should take care of your problem I think. Good luck