Effect of Perforating an Intake Pipe on the Interior Noise of a Passenger Car

The intake pipes designed by some experienced engineers have small holes. However, the role of these small holes is yet to be fully understood by most engineers. At present, the only research on this issue is also controversial. This work aims to reveal the effect of perforating an intake pipe on the interior noise and provide some suggestions to automotive engineers when applying this method. First, the effect of these small holes on the source strength of the intake nozzle and perforated region is theoretically analyzed. Thereafter, the noise transfer functions of the intake nozzle and perforated region to the target response point in the cab are measured on the basis of the reciprocity principle. Finally, the effect of perforating the intake pipe on the interior noise is studied by simulating the intake noise of the experimental car with an external sound source. Results show that perforating the intake pipe can increase the order noise component of the intake noise and reduce the mid-high frequency noise in the cab, thereby improving the powerful sound quality and reducing the feeling of noisy.