Analysis of High-frequency Combustion Noise Generation Mechanism in Pre-chamber Jet Combustion Gasoline Engine

- Analysis of Acoustic Resonance Modes in Combustion Chambers -

Abstract

In the development of a pre-chamber jet combustion gasoline engine that improves thermal efficiency by realizing rapid combustion, an increase in high-frequency combustion noise in the 6-9 kHz band has become an issue. Such combustion noise is often an issue in the development of diesel engines, not gasoline engines, and is known to be caused by acoustic resonances in the combustion chamber. Therefore, the resonance modes of the combustion chamber of this engine were analyzed through calculations using finite element models and experimental modal analyses. As a result, it became clear that changes in the resonance frequencies occurring in conjunction with changes in combustion chamber volume affect the characteristics of the in-cylinder pressure, which is the cause of the combustion noise described above.