Correlation Study of Low Frequency Engine Order Noise Prediction at Compressor Inlet for a PHEV and Resonator Tuning

Sound Pollution has become one of the major environmental concerns for global automotive industry in the current era. Air Induction System (AIS) plays an important role in engine performance and vehicle noise. An ideal design of AIS provides debris free air for combustion and reduces the engine noise heard at snorkel. The objective of this work is to correlate low frequency engine order noise prediction at compressor inlet and snorkel inlet for a 2.0L I4 turbo engine of a Plug-in hybrid vehicle (PHEV) for better acoustic performance without compromising on engine performance. Commercial 1D simulation software GT-POWER, Simcenter 3D and Hypermesh is used for this work. Transmission loss results with respect to frequency of air-box with ducts and intake manifold with charge air cooler are plotted from 0 to 1000 Hz. The air intake system shows good correlation between 3D and 1D till 600 Hz. Compressor and snorkel noise results, especially the firing order and its harmonic orders are compared with measurements from 1500 to 5000 rpm. Helmholtz resonators are deployed on the clean side duct (CSD) to attenuate the snorkel noise. The optimized design shows better acoustic performance than the original design. Deployment of advanced software and experimental methods leads to First Time Right product development by effectively reducing valuable design cycle time and can be further used in the field of research for future vehicle programs.