抗性消声器插入损失的有限元法的探讨

摘要

As a main evaluation indicators of muffler,the advantage of insertion loss is intuit and utility.However, the insertion loss often depends on not only the performance of muffler itself, but also is related to the performance of the whole system device.Insertion loss is more closer to the actual in muffler performance prediction than transmission loss.Insertion loss of the reactive muffler with connection pipe is computed by applying four-parameter method and finite element method,which indicates that there are defects for one- dimensional wave theory in terms of muffler performance. The re fore an experimental model for simple muffler insertion loss measuring is established, and then the insertion loss of muffler is obtained through applying direct simulation method.The results show that insertion loss of muffler with connection pipe obtained by calculation of four-parameter method is coincidence with that by direct simulation.%插入损失作为消声器的主要评价指标,优点是比较直观、实用.不过插入损失往往不仅决定于消声器本身的性能,而且与系统总体装置的情况密切相关.插入损失对消声器性能的预测比传递损失更接近实际情况.应用四端子网络法与有限元相结合法对有连接管的抗性消声器的插入损失进行计算,说明了一维波动理论在消声器性能方面的缺陷.建立了简单抗性消声器的插入损失测量的试验模型,用直接模拟试验的方法,获得消声器的插入损失.结果表明,四端子法计算得到的加连接管的消声器插入损失与直接模拟试验方法所得的结果吻合良好.