Evaluation and Improvement of the Sound Quality of a Diesel Engine Based on Tests and Simulations

Abstract

Traditional acoustic evaluation of a diesel engine generally uses the A-weighted sound pressure level (AWSPL) and radiated sound power to assess the noise of an engine prototype present in an experiment. However, this cannot accurately and comprehensively reflect the auditory senses of human subjects during the simulation stage. To overcome such shortage, the Moore–Glasberg loudness and sharpness approach is applied to evaluate and improve the sound quality (SQ) of a 16 V-type marine diesel engine, and synthesizing noise audio files. Through finite element (FE) simulations, the modes of the engine’s block and the average vibrational velocity of the entire engine surface were calculated and compared with the test results. By further applying an automatically matched layer (AML) approach, the engine-radiated sound pressure level (SPL) and sound power contributions of all engine parts were obtained. By analyzing the Moore–Glasberg loudness and sharpness characteristics of three critical sound field points, an improvement strategy of the oil sump was then proposed. After improvement, both the loudness and sharpness decreased significantly. To verify the objective SQ evaluation results, ten noise audio clips of the diesel engine were then synthesized and tested. The subjective evaluation results were in accordance with the simulated analysis. Therefore, the proposed approach to analyze and improve the SQ of a diesel engine is reliable and effective.

A New Method of Identifying the Limit Condition of Injection Pump Wear in Self-Ignition Engines

“…Besides, the spectrum of generated acoustic emission pulses is strictly dependent on phenomena occurring in the macro and microstructure of the material (e.g., the fuel injection pump). The spectral analysis allows us to determine the correlation of signal functions with various frequencies [14,15]. In the case of high correlation (high correlation coefficients for sine or cosine) the occurrence of visible periodicity in the given frequency can be expected.…”

Warning Effect Evaluation and Control for Vehicle Turn Signal Sound

“…In recent years, vehicle sound quality has been extensively studied, such as vehicle interior noise, 1, 2 engine noise, 3,4 door closing sound, 5,6 vehicle suspension shock absorber rattling noise, 7 horn sound, 8 and warning of electric vehicle. [9][10][11] These studies include two major parts: subjective evaluation and objective evaluation.…”