Research On The Robust Design Technology Of Adjustable Frequency Band Gap

In the noise control process of an excavator, we found that the optimized exhaustmuffler could achieve good results to the prototype but not to other excavators of thesame batch. Because of the difference of the speed, the power and the displacementbetween different engines and the limitations of the pipeline process, it had frequencyoffset in different excavators. In response to this phenomenon, in this paper, the designmethods of adjustable frequency exhaust muffler are explored.The transmission of the muffler was calculated by test and simulation and the targetfrequency which needs to be optimized was found out. The effect was studied to findout how the cavity volume, the cross-sectional area and length of the connecting pipe,the cross-sectional area of the competent and temperature parameters affect on theresonant frequency and the transmission loss of the resonator. Several types of specialresonators were studied to find out an effective structure that can expand the bandwidthof the muffler. In reference to the structure and size of the original muffler, anadjustable frequency exhaust muffler was designed, and the transmission loss and flowfield of the muffler were analyzed by simulation.Several controllable size of the muffler had conducted a parametric design and thepreferred value of those parameters was checked out. The tolerance design of themuffler was done by experimental design and the analysis of variance to ensure that itcan’t has a huge impact on the silencer value of the target frequency when it hasfluctuation in the manufacturing process of the muffler.