Radar/infrared integrated stealth optimization design of helicopter engine intake and exhaust system

Abstract

Along with the diversification and sophisticated development of detection methods in modern warfare, helicopters are increasingly subject to unilateral or simultaneous threats from radar and infrared detectors. In order to improve the survivability and operational effectiveness of the helicopter, a comprehensive stealth approach based on Pareto solution is presented. Considering the geometric constraints and aerodynamic characteristics of the engine intake and exhaust system, the model of the system is established by the full factorial design, the internal, central and external flow fields are constructed, then the high-precision computational fluid dynamics method is used to simulate the total flow field under the rotor downwash airflow in hovering state. The radar cross section of the system is evaluated by the physical optics and physical theory of diffraction. Based on the Monte Carlo and ray tracking method, the infrared signature of the system is calculated and analyzed in detail. Under the comprehensive evaluation and selection of comprehensive stealth approach, the optimization model of the system is continuously established and updated. The ultimate design has achieved good results in both radar cross section reduction and infrared radiation suppression and the proposed method is effective and efficient for radar/infrared integrated stealth of helicopter engine intake and exhaust systems.