Research on Experimental Method for Obtaining Independent Combustion Noise of Internal Combustion Engine

Table 3

Empirical parameters of engine body structure attenuation.

Center frequency (Hz)	Transfer function value (dB)	Center frequency (Hz)	Transfer function value (dB)
100	−143.0	1000	−96.5
125	−137.5	1250	−93.3
160	−132.4	1600	−90.8
200	−127.8	2000	−89.7
250	−122.3	2500	−89.5
315	−117.2	3150	−90.6
400	−112.3	4000	−94.2
500	−108.2	5000	−99.2
630	−103.8	6300	−105.6
800	−100.0	8000	−116.0