A simple algorithm of saddle-point method (SPM) in eN method was presented by using internal wave theory

and distribution of N was computed on a model made up of plate

cone and cylinder at the cases of 30-45 km altitudes

Mach number of 10

attack angles of 0° and 10°. The results and conclusions show that: as the altitude increases

the transition position moves downstream

and the transition area becomes smaller and even disappears. On the plate part (windward side)

the transition possibility in 10° attack angle cases is bigger than that in 0° attack angle cases

and the transition area is larger too. But on the cone part (leeward side)

the transition possibility in 10° attack angle cases is less

and the transition area is smaller

even inexistence. And the transition positions of these two series of cases are different.