Design and thermo-structural analysis of 2D exhaust nozzle with multiple composite layers

The IR(Infrared) signature generated by hot sections of the aircraft results in severely reducing aircraft survivability during the mission because this signature increases potential to be traced by IR detection system. This article deals with the novel 2D exhaust nozzle for reducing IR signature, and design process by thermo-structural analysis for satisfying thermal and structural requirements. The novel 2D exhaust nozzle is adopted as multiple composite layers with variable elliptical cross-sections for dispersing high temperature core gas flow and enhancing mixing performance with bypass air flows. Also, this study defines 1D thermo-structural model based analytical method for calculating initial performances of the 2D exhaust nozzle. In addition, initial design parameters are firstly determined by the proposed 1D thermo-structural model. Furthermore, detailed thermo-structural characteristics of the 2D exhaust nozzle are investigated by the finite element method (ABAQUS). Based on the database, the minimum thickness of the insulator layer can be determined to maintain structural rigidity and suppress increase of temperature at the outermost surface of the nozzle. Consequently, we review thermo-structural stability of the 2D exhaust nozzle by comparison of the finite element analysis and engine application tests.