Exhaust noise - A new novel in-situ measurement technology in duct

• The noise emission from large internal combustion engines, from 500 kW to 20 MW, is inherently difficult to predict with a high degree of confidence. How the actual noise field propagates within a complex exhaust gas system and how to measure exhaust noise where the gas flow in the duct could be as high as 40 m/s and temperature about 350 degree. This translates to increased cost for silencer over-sizing or added costs associated with an exhaust gas system that fails to meet the required noise signature. This paper deals with a new and verified hot gas (< 600 C) in-situ noise measurement technology called SESaM. It makes it possible to accurately measure source strength and specific insertion loss of the various components in the exhaust train behind large 2 or 4 stroke diesels and power plant gas turbine, also under field conditions. When designing an exhaust system for diesel engine it is most important to have a correct source spectrum for the engine and the noise requirement raised by the final customer in order to do the precision design for the attenuation in the system. In the past the source spectrum of diesel engines always has been an issue of large uncertainty due to the fact that no general reliable measurement procedure exists. The paper presents the practical induct SESaM technology and discusses measurement results versus the time consuming and less accurate classic method.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Publication and Content Type

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