Research on the sharpness of combustion noise of three-cylinder GDI engine based on adaptive cyclic Wiener filter method

Abstract

In order to analyze the sharpness of combustion noise of the gasoline direct injection (GDI) engine, the in-cylinder pressure and noise of different loads and speeds of a three-cylinder GDI engine are measured. An adaptive cycle Wiener filter method is proposed to separate the combustion noise. The result indicated that the proposed method can overcome the drawbacks of the original Wiener filter method and is able to separate high-frequency combustion noise components more accurately and effectively. The sharpness of the combustion noise is calculated by the Zwicker method and Aures method, and the comparison results show that the Aures method is more suitable for evaluating combustion noise. The influence of different loads and speeds on the sharpness of combustion noise is investigated by the proposed method systematically. The results indicated that at low speed (1500 r/min), the combustion noise and sharpness will increase with the load while at medium (3000 r/min) and high (5500 r/min) speeds, the combustion noise under half load (50%) has the highest sharpness. Excessive high load (100%) and too low load (0%) both suppress the generation of combustion noise. As for the same engine load, a higher engine speed will lead to higher combustion noise and sharpness.