I don't know much about numerical aerodynamics, but assume that you are interested in a finite element solver. I googled a bit and found the following projects. The first is a 2d finite element solver for python. The second is a 2d finite element solver without python.
http://ellipt2d.sourceforge.net/ http://www-rocq1.inria.fr/gamma/cdrom/www/freefem/eng.htm You can probably find more libraries by looking at http://netlib.org. -- http://mail.python.org/mailman/listinfo/python-list