Performance study of infrared suppression devices with efficient air mixing using streamlined horn-shaped deflector

This study proposes the installation of a streamlined horn-shaped deflector (STD) within the infrared suppression (IRS) system to enhance the infrared suppression performance and air entrainment capability of naval exhaust systems while reducing energy consumption . Computational fluid dynamics (CFD) is used to systematically analyze the impact of different deflector structures on the flow field, temperature field , and thermodynamic performance. The focus of this research is to evaluate the effects of three dimensionless parameters—penetration length into the mixing tube of the deflector (L/D nz ), height of the deflector (H/D nz ) and diameter of the deflector (D/D nz ) on system performance . Initially, a single-factor analysis is conducted to explore the influence of each parameter on the evaluation metrics. Subsequently, a multi-objective analysis is performed, employing the CRITIC weighting method for comprehensive optimization. The results indicate that, compared to traditional designs, STD significantly enhances air entrainment rate and reduces system temperature while maintaining low pressure loss. Among the parameters, L/D nz has the greatest impact on performance. Compared to the baseline configuration , the optimal configuration improves the average temperature of mixing tube wall ( T mt,ave ), air entrainment rate ( η ), average outlet temperature ( T out,ave ) and pressure loss ( P ) by 2.47 %, 4.65 %, 1.13 %, and 0.18 %, respectively. • This design moves beyond traditional petal configurations, using a streamlined deflector that is more feasible to produce, despite challenges. It improves wall and outlet temperatures by reducing the high-temperature mainstream's impact on the wall, enhancing thermal efficiency. • Unlike traditional IRS devices, the deflector aims to achieve lower pressure loss, addressing the typical trade-off of deflectors causing pressure increases. This approach aligns better with practical engineering needs. • Through orthogonal experiments and multi-objective analysis, the optimization of parameters is made more comprehensive, thereby providing valuable guidance for practical applications.