Producing Mechanism on Flow Regeneration Noise from Muffler Element with Inserted Tube

Abstract

Structure parameters of muffler element with inserted tube are firstly determined, it is analyzed to the inserted length effecting on sound power of flow regeneration noise and frequency characteristic, and distribution feature of flow velocity and turbulence kinetic energy is explored by numerical computation of flow field. It is shown that flow regeneration noise of muffler element with inserted tube forms according to confined incomplete flow-inject, it presents wide frequency band, and its energy focus on middle and low frequency, especially it is about 600Hz, Strouhal Number is 0.5. When its structure parameters is constant, distribution feature of flow velocity and turbulence kinetic energy doesn’t change with flow velocity, and difference is numerical dimension, and turbulence kinetic energy distributes near inserted tube in wall, this is area occurring flow regeneration noise, so producing mechanism of flow regeneration noise from muffler element with inserted tube is achieved.