Effect Factors Analysis of Flow Noise Generation from Perforated Duct Muffler Element

Flow noise regeneration from perforated tube muffler element was measured on the self-developing test bench, relationship model on total sound power of flow regeneration noise and structure parameters and work condition was established. Its model parameters were solved making use of hyper static least square method. Using the model effect factors of flow noise generation were discussed. Result shows that the reducing of the perforated diameter and the perforated part length is favor of the reduction of flow noise, and perforated ratio and expansion chamber diameter have less effect on flow noise. After analyzing spectrum structure of flow regeneration noise, it is displayed that with the increase of flow velocity projected peak value frequency has the trend of moving to middle and high, its intensity also becomes stronger, and sound energy in some the frequency accounts for about 60% of the total energy, Strophe number is the range of from 0.2 to 0.35.