Multi-objective optimization of a muzzle brake to enhance overall performance

The structure of a muzzle brake has a significant effect on the overall technical performance of an automatic weapon. This paper presents a multi-objective optimization of a muzzle brake that enhances the overall performance, that is, it increases the muzzle brake efficiency and simultaneously decreases the noise emanating from the rifle upon discharge. A standard impact-reaction muzzle brake was selected as the research object. The optimal values of four structural parameters were established through multi-objective optimization. The process consists of design of experiments, coupled computational fluid dynamics and computational acoustics calculations, an approximation model, and a multi-objective genetic algorithm. Based on the results, the correlation and sensitivity between the structural parameters and the objectives were investigated. Moreover, the reaction force and noise directivity of the optimized muzzle brake were compared with those of the original design. The results show that the disk angle of the side holes was the most sensitive design variable for both efficiency and noise. The optimized muzzle brake had a remarkable improvement in brake efficiency accompanied by only a small increase in the sound pressure level, so it showed better overall performance. The optimization method proposed in this paper is practical and effective for engineering design.