Improvement of Acoustic Characteristics of Motor Vehicle Intake System Based on Calculation and Experimental Research

The article considers the technique and results of computational studies of the acoustic characteristics of the elements and the motor vehicle intake system. It describes the purpose and operation characteristics of the intake system. It is noted that the waves occurring in the intake tract, the nature of which depends on the geometry of the intake tract and the operating mode of the engine, determine the acoustic characteristics of the intake system and can improve or worsen the filling of the cylinders. Adding Helmholtz resonators to the manifolds improves the acoustic characteristics of the intake system depending on the engine speed and maximizes filling of cylinders for different speed modes. This allows to increase the power, economic, environmental performance of the engine and reduce the gas-dynamic noise emitted by the cutoff of the intake tract. A resonator was developed on the basis of finite element modeling to replace the connecting pipe of the air supply hose of hot air for improving the acoustic characteristics of motor vehicle intake system. The range of transmission loss (TL) of intake system has been calculated to evaluate the performance of the elements and the intake system in acoustical performance. The overall level of sound pressure at idling speed is determined by radiation in the frequency range 100–5000 Hz. In this range, in most one-third octave, the resonator lowers the sound pressure up to 5 dBA.