wrote:
sir,
i am working on flight dynamics in iit madras. in my project i
need fly the aircraft from angle attack 0 to 90 deg. and get all the
stability derivatives.
so which soft ware i prefer x plane or MSFS ?

Please don't take my reply as an ultimate one, or even remotely a
professional advice. I am not a pilot, nor an expert. I am really an
aviation enthusiast and an avid MSFS user.

If you only need to perform casual experiences, any of those simulator
will be fine. If you need the best simulator in regards to flight
dynamics, I was told that x-plane was slightly more realistic in that
regards, although I have never tried that one myself.

If you ever go with MSFS, I would recommend that you also buy at least
one payware aircraft, or at least get a really good freeware, since many
of them include better flight dynamics than those included in the box.
Again do some research. You may want to join
alt.games.microsoft.flight-sim where me an others will be happy to help.

You might also want to check out (read 'research') Flight Gear, an open
source flight simulator which was originally developed around some
flight dynamic simulator. It is not as advanced when compared with MSFS
or X-Plane, but possibly will be better regarding flight dynamics. But
again, do some research to see what others think of it, I did not have
an occasion to try it out yet, although I plan to soon.

By the way, your aircraft will have stalled long before you ever get an
angle of attack of 90 degrees, but that you probably already know

Hope this helps,

Tom