EXPERIMENTAL INVESTIGATION INTO THE EFFECTS OF INTAKE SILENCER ON COMPRESSOR AERODYNAMIC NOISE REDUCTION

摘要

Compressor aerodynamic noise reduction has recently become a much more important topic in low noise marine diesel design, owing to its dominating position in high frequency noise in turbocharged diesel engine. This paper describes an intake silencer mounted to the compressor inlet pipeline to reduce compressor noise. First, compressor aerodynamic characteristics and the design of intake silencer are brief introduced. Then, a series of experiments perform to verify the intake silencer acoustic attenuation performance, including silencer static acoustic test, compressor aerodynamic noise test and turbocharger radiated noise test. The IL (insertion loss) measured in silencer static acoustic test is 25.7dB (A), meanwhile, the results in compressor aerodynamic noise test and turbocharger radiated noise test show that the silencer can reduce compressor high frequency noise effectively, the clear peak at BPF (blade passing frequency) nearly disappear with silencer installed. However, it also shows from the experimental results that besides significantly acoustic attenuation performance in high frequency, low and medium frequency noise components must take into account in silencer design.