Noise contribution analysis of a vehicle passenger compartment

In this study, integration of acoustic source quantification (ASQ) and SEA methodologies is aimed to model the interior noise level inside the passenger compartment. The ASQ direct method, briefly explained in theory section, has been used to perform panel acoustic contribution analysis (PACA), in order to investigate regions with panels that contribute primarily to the interior noise level and to determine opportunities for refining the interior noise levels within vehicles. To determine the airborne contributions of engines, the ASQ indirect method, briefly explained in theory section, has been applied. By creating a contribution model using MATLAB (PACA and engine ASQ), the interior noise level of the vehicle has been calculated and correlated with the test results. By performing further analysis on the interior noise contribution model and focusing on the panel contributions, the regions with the most contributing panels have been determined and interior noise refining actions have been applied. By applying interventions, which are the refining outputs of the panel acoustic contribution analysis, an improvement in the A-weighted level of up to 3 dB for a few engine speed ranges has been obtained for the overall noise level of the vehicle. In addition to the panel contribution analysis, which is the primary focus of this study, thickness optimization of the inner dash isolator has been performed for a correlated SEA model, which confirms that no performance loss occurred in the acoustic transfer functions from the engine to the passenger compartment. The physical prototype of the optimized inner dash isolator has been assembled in the vehicle during the panel contribution analysis validation tests.