A suit of parameter design methods of double juxtaposition 3-D asymmetrical several-S-shaped nozzles based on CFD numerical simulation technology was estabished

and the exactitude and feasibility of the parameter design methods were approved primarily. The several-S-shaped centerline on the condition of Z direction eccentricity angle of 0: Y direction eccentricity angle and location parameter L of the first S curve are smallest

and the two parameters of the second S curve are biggest. The two parameters of the third S curve are between the biggest and the smallest of the pre two S curves. Every S curve uses the law which turns slowly at inlet

but quickly at outlet to favor controlling the airflow separation and turbulence of the leeward. The section uses the law which shrinkages quickly and turns slowly at inlet

but shrinkages slowly and turns quickly at outlet

and the aspect ratio and the side obliquity varies at the same rate at inlet and outlet. The side obliquity only distributes on the first S curve to favor stabilizing fluid flow and increasing stealth performance. Confluence implement uses wedge fundus/highness aspect ratio restriction

and it should not exceed 0.26.