I am working on a project which involves air nozzles. I am interested in estimating the time it takes for air particles after they leave the nozzle to reach a particular distance away. I have the following information--- a converging nozzle, the speed with which it is coming out of the nozzle (I know when the air is choked it comes out at Mach number). I am aware that this problem is complex and would be very difficult to solve it precisely without intensive Mathematical Models. I just want a rough idea/guideline. Any help will be appreciated.
http://postimg.org/image/cw53jnibx/
Above is a profile of the nozzle