Can ANSYS 10.0 model the sound attenuation of a muffler? I am not matching
the attached benchmark exactly.
Yes, ANSYS 10.0 can model the essential behavior of a muffler which produces attenuation due to cancellation with the reflection from the opening to the large diameter chamber. You are performing the benchmark as a harmonic analysis when the benchmark was done as a transient with just a pulse loading. This does not produce the resonance that you are seeing. "The velocity inlet has a time varying velocity imposed at the start of the solution in the form of a full period sinusoid with an amplitude of .05 m/s. After the sinusoid is complete, the velocity remains zero at the inlet for the remainder of the solution." To model that you should have done a transient with just a single period of applied flow and coupled pressure. Performing a harmonic analysis with an applied pressure could explain why you are getting a negative transmission loss for some frequencies (resonance in the inlet pipe.) |
||
|