METHOD FOR IMPROVING THE PERFORMANCE OF A BYPASS TURBOJET ENGINE

摘要

The engine has a cooling air nozzle (T) with a throat arranged before a cooling air outlet orifice (6). An annular section of the throat has a nominal area fixed by thermodynamic cycle of the engine and lower than an area of the orifice such that a convergent-divergent nozzle (15) is formed at a rear part of an annular cooling air channel (12). The area of the orifice is adapted to a reference value of an expansion ratio of cooling air (9) comprised between extreme values of expansion ratios respectively corresponding to starting and ending of a cruising phase. An independent claim is also included for a method for improving performances of a ducted fan turbine engine that is mounted on an aircraft before accomplishing a determined flight mission.