Sound Source Localization Analysis in the Combustion Cycle of ICE Powertrains
* Presenting author
Noise optimization of powertrains usually occurs in the late stages of their development cycle. This exposes the manufacturer to the risk of detecting non-optimized noise contributors, causing sound problems which are difficult to be solved when the design process is already too advanced. Sound source localization techniques, supported by advanced processing tools, enable to front-load the powertrain noise assessment, speeding up the development cycle. The application of a cyclic Wiener filter relying on reference cylinder pressure sensors, effectively breakdown the microphone array data into a combustion component, related to the thermal activity occurring in the Internal Combustion Engine cylinders, and a mechanical component originating mainly from auxiliary systems in the powertrain such as water pumps, air conditioning units, alternators, etc. Sound source localization on these separated components allows to identify the main sources related to combustion and mechanical noise contributors. The powertrain – mechanical and/or combustion - noise can also be analyzed in segments of the combustion cycle itself. This requires a pre-processing in the angle domain, first, after which sound source localization is applied on angular ranges. This paper describes these methodologies, their synergies and their application on engine test bench experimental data to prove their industrial exploitability.