Insonorisation of a car air conditionning system: application of an active/passive absorber

摘要

this work is part of a project examining the implementation of active noise control in a car air conditionning system. In our system, a part of the problem is related to the flow itself. Indeed, the more the duct system geometry is complex, the more the internal flow is disturbed, leading to a high degree of turbulence. So the signal spectrum recorded by the microphone is the sum of this uncorrelated turbulent signal and the true noise signal. Taking into account these considerations, the purpose of the present work is to find the best strategy in order to cancel the noise coming from a centrifugal fan using active noise control on a real air conditionning system. Some real time tests in the car air conditionning system are finally presented.