Collaborative optimization of two-dimensional convergent divergent exhaust system based on Kriging model

In order to enhance the performance of the two-dimensional exhaust system during high-speed cruising and enhance aircraft survivability against infrared-guided weaponry, this study undertakes a systematic optimization of the geometric and thermodynamic parameters governing the two-dimensional exhaust system. The optimization objectives encompass augmenting both the discharge coefficient and the thrust coefficient of the nozzle while concurrently mitigating the infrared radiation intensity emanating in the tail direction. Imposing limitations on the infrared radiation intensity across diverse detection angles, the study further imposes constraints on the thrust efficiency and deflection efficiency of the thrust vectoring nozzle subsequent to a 15° deflection. Such measures ensure the maintenance of optimal stealth capabilities across all detection angles while preserving the unhampered thrust vectoring performance of the nozzle. This study employs the optimal Latin hypercube method and Kriging surrogate models in conjunction with collaborative optimization techniques to address multidisciplinary design optimization challenges. Comparative analyses with the initial design revealed significant enhancements: up to a 2.88% increase in the discharge coefficient, a maximum 0.53% increase in the thrust coefficient, and a notable reduction of up to 17.09% in tail direction dimensionless infrared radiation intensity, validating the effectiveness of the optimized exhaust system design.