simple systems

dibyadeep

hiii, i am new to numerical analysis, and am trying to solve some coupled, 3d , unsteady flow simulations. i was suggested by some people to use freefem, a software package, for pdes, but as far as i could understand it was able to handle only 2d equations, and if at all 3d had to be solve, it had to be axis-symmetric. so could you suggest some package preferably free, which can handle 3d, non-axis-symmetric, unsteady situations.