Study on the Combustion Noise Characteristic of Low Speed Diesel Engine

Abstract

In recent years, the Low speed two stroke diesel engines are widely used as the main power device of big ship for its so many advantages such as the high power, better economical efficiency and good maintenance. However, the problem of diesel strong vibration and noise becomes a more and more serious at the same time. Because of the Construction Features of marine two-stroke low-speed diesel engine, the structure has to be suffered different kind of forces when it runs. In considering the source of vibration, the whole noise can be divided into combustion noise、machinery noise and aerodynamic noise. The combustion noise caused by cylinder pressure is the most important part of diesel noise. In this paper, the cylinder pressure curves are tested. The internal combustion engine dynamics and the equivalent node load are used in the calculation procedure to achieve the real condition simulation. The loading program is made to simulate the change of cylinder pressure and the move of piston. The transient response of the diesel engine is calculated. The characteristics of diesel caused by cylinder pressure are analyzed.The response analysis can be used to the vibration control.

The Use of Denoising and Analysis of the Acoustic Signal Entropy in Diagnosing Engine Valve Clearance

“…In [33][34][35][36][37] the authors proposed the application of time and frequency domain signal processing methods for, inter alia, detecting combustion knocking. Methods of signal recording and processing are also used in studies which deal with pressure identification in the engine cylinder, and in the engine's noise assessment, which is discussed in [38][39][40][41]. In [10,[42][43][44] a broad master base scope, among others of point characteristics, was used for teaching artificial neural networks, which consequently enabled the diagnostics of damage to engine injection and other systems.…”