Transient in cab noise investigation on a light duty diesel passenger vehicle

摘要

A diesel engine in cab sound quality for passenger car market is scrutinized more closelyrnthan in the mid to heavy duty diesel truck applications. This is obviously due to thernincreasing expectations from the customers for gasoline like sound quality. This paperrndeals with a sound quality issue recently investigated on a light duty diesel engine for arnpassenger van application. The objectionable noise complaint occurred during the vehiclerntransient operating conditions and was found to be caused by the change in the pilotrnquantity over a very short period of time. The root cause of the noise complaint wasrninvestigated on the noise complaint vehicle as well as simultaneously on a standalone enginernin the noise test cell. Several critical combustion and performance parameters werernrecorded for diagnosing the issue. In addition, various standard sound quality metrics werernemployed to differentiate the sound quality of the objectionable noise. The issue wasrnresolved and verified by making appropriate changes to the engine calibration withoutrnaffecting other key requirements such as emissions and fuel economy. Finally, the findingsrnfrom the experimental tests are summarized and appropriate conclusions are drawn withrnrespect to understanding, characterizing, and resolving this transient, combustion relatedrnimpulsive power train interior noise issue.