A Novel Virtual Approach of Air Intake System Acoustic Sensitivity Study for Passenger Vehicle

Modern day customer awareness on noise and comfort is extremely increasing, which demands OEM manufacturers to focus on NVH attributes and to meet environmental legislative requirements. Noise generation mechanism in Air Intake System (AIS) is one of the major sources for vehicle interior noise and it occurs mainly because of air column oscillation by sharp pressure pulsation from opening and closing of valves in engine cylinders. Air intake system designer has immense challenges to attenuate intake noise during design stage, in order to meet the vehicle interior noise requirements by using multiple resonators to tune the desired broad band frequencies and to choose the optimum number of resonators. The placement of resonator on both the clean duct and dirty sides is also a key challenge for better noise reduction from air intake system. Transmission loss (TL) is the property of acoustic system to evaluate NVH performance of air intake system during system level design development stage. This paper describes about the three dimensional (3D) analysis approaches using commercial tool, which are used to compare the acoustic characteristics of AIS using resonators, effect of AIS elements such as manifold, and air filter element for better noise attenuation. Repositioning of resonator in the air clean side duct region is proposed for noise improvement in the AIS. The effect of snorkel design in the engine compartment on vehicle interior noise performance is also studied through transfer function at dash panel region. The level of correlation in transmission loss performance between physical test and simulation results achieved at system level is also highlighted in this paper.