Numerical Investigation of the Flow Structure and Acoustical Noise in a Suppressor

Abstract

The noise created when a firearm is fired has a lot of adverse effects on humans and the environment, so analyzing and attenuating this noise is essential. This study aimed to examine propellant flow and the sound generated by this flow using a hybrid computational fluid dynamics and computational aeroacoustics method. The compatibility of this numerical study was also validated by comparing it with the experimental result. The impact of critical parameters, such as the shape and number of baffles of the suppressor, was studied. Finally, the overpressure and acoustics results of different suppressors were compared with each other and with the unsuppressed condition. According to the result, the suppressor with curved baffles shows a better performance. When the exit pressure at the tip of suppressor compared to the initial inlet pressure to the suppressor the percentage drop in overpressure was 76.01%, 78.79% and 81.3% for the suppressor with one, three and five curved baffles, respectively. For condition without suppressor, 169.49[Formula: see text]dB of SPL was recorded. When using a suppressor without a baffle, this value was reduced to 162.13[Formula: see text]dB. For the suppressor with one, three and five curved baffles, the SPL value was 160.234[Formula: see text]dB, 159.43[Formula: see text]dB and 158.11[Formula: see text]dB, respectively. Generally, this study shows that the suppressor’s efficiency is directly proportional to its shape and number of baffles.