分流气体对冲排气消声器气流再生噪声模型研究

Noise model of airflow regeneration in exhaust muffler with split-flow gas hedging

对分流气体对冲排气消声器气流再生噪声进行了数值计算,通过试验验证了计算方法的准确性。以气流再生噪声总声压级为响应值,使用Design-Expert软件设计了气流再生噪声试验,根据回归分析建立了总声压级与试验因素(内腔直径、对冲孔形状、对冲孔中心距、内腔分流单元锥角、气流速度)之间的数学模型,并检验了模型的显著性。深入分析了不同因素二阶交互作用对气流再生噪声的影响规律。结果表明:随着气流速度的增大气流再生噪声显著增大,斜率都超过了1;对冲孔形状和对冲孔中心距对气流再生噪声影响较显著,且当冲孔形状为矩形、对冲孔中心距为平均值时,气流再生噪声较小;内腔分流单元锥角和内腔直径对气流再生噪声影响较小。以气流再生噪声为优化指标,得到了最佳试验条件。

Numerical computation was performed for airflow regeneration noise in exhaust muffler with split-flow gas hedging,and the correctness of the computation method was verified with tests.Taking the total sound pressure level of airflow regeneration noise as the response value,the test for airflow regeneration noise was designed using the software Design-Expert.According to regression analysis,a mathematical model of total sound pressure level with test factors including diameter of internal cavity,shape and center distance of hedging hole,cone angle of internal cavity split-flow unit as well as airflow speed was established using Box-Behnken test design scheme,and the model’s significance was tested.Influence laws of second-order interaction of different factors on airflow regeneration noise were deeply analyzed.The results showed that with increase in airflow speed,airflow regeneration noise increases significantly,and its gradient is more than 1;shape and center distance of hedging hole have a significant impact on airflow regeneration noise,and when shape of hedging hole is rectangular and center distance of hedging hole is average value,airflow regeneration noise is smaller;cone angle of inner cavity split-flow unit and diameter of inner cavity have smaller influence on airflow regeneration noise;the optimal test conditions are obtained by taking airflow regeneration noise as the optimization index.