直接式火药固钉器消声结构设计及仿真分析

Design and Simulation Analysis of the Silencing Structure of a Direct Gunpowder Nail Fixer

针对直接式火药固钉器射钉过程中膛口噪声过大问题,在其内部设计了开孔式消声结构。基于LS-DYNA与Fluent联合仿真,分析消声结构的孔径和孔距对射钉威力和膛口噪声的影响。在LS-DYNA中基于爆轰理论选用ALE流固耦合算法,对炸药在膛内爆炸射钉侵彻靶板过程进行仿真分析,分析孔径和孔距对射钉威力的影响。提取炸药爆炸瞬间膛内压力值作为膛口噪声分析的初始压力值,以射钉侵彻靶板的速度作为边界条件,基于动网格技术,采用Fluent软件分析了射钉过程中的流场和噪声,并与噪声试验结果进行了对比。结果显示,随着孔径的增加,射钉侵彻深度近似呈线性下降;随着孔距增加,越靠近爆炸中心位置,侵彻深度呈非线性下降。在保证满足射钉威力的前提下,孔径和孔距最佳设计值分别为1.75 mm和23 mm,相对无消声结构可降低噪声约10%。

In response to the problem of excessive muzzle noise during the nail shooting process of the direct gunpowder nail fixing device,a perforated silencing structure has been designed inside it.Based on the joint simulation of LS-DYNA and Fluent,we analyzed the impact of the aperture and hole spacing of the silencing structure on the nail power and muzzle noise.In LS-DYNA,ALE fluid solid coupling algorithm is selected based on detonation theory.The process of explosive penetration into the target plate was simulated during the explosion of the nail in the bore,and the influence of aperture and hole spacing on the power of the nail shooting was analyzed.Extracting the pressure value in the chamber at the moment of explosion as the initial pressure value for muzzle noise analysis,using the velocity of the nail penetrating the target plate as the boundary condition,the flow field and noise during the nail shooting process was analyzed with Fluent software based on dynamic grid technology.The results were compared with the noise test results.The results show that as the aperture increases,the penetration depth decreases approximately linearly.As the hole spacing increases,the penetration depth decreases nonlinearly as it approaches the center of the explosion.On the premise of ensuring power,the total noise pressure level is 109.1dB when the aperture is 1.75mm and the hole spacing is 23mm,10%lower than that without silencing structure.