There are several main noise components of diesel generator sets

1. Low-frequency pulsating noise caused by periodic exhaust;

2. Gas column resonance noise in the exhaust pipe;

3. Helmholtz resonance noise of a cylinder;

4. Jet noise produced by high-speed air flow through the gap between the exhaust gate ring and zigzag pipe;

5. The eddy current noise, and the regenerative noise generated by the exhaust system under pressure wave excitation in the pipe form a 

continuous high-frequency noise spectrum;

the frequency is above 1000 Hz, and the frequency increases significantly with the increase in air velocity.