Applications of Sound Intensity Measurements to Gas Turbine Engineering

Abstract

Recent advances in signal processing techniques have made the measurement of sound intensity a practical reality. The newly developed sound intensity meters can indicate both the magnitude and direction of sound. This is a major advantage over the traditional sound level meter which does not have such directional sensitivity. Sound intensity meters can, therefore, make accurate measurements under adverse conditions, such as onshore or offshore, where sound level meters may be unsuitable. This makes the detailed assessment of the sound power output of a gas turbine package, operating in the field, practicable. Individual components of a gas turbine train can be evaluated so that the dominant noise sources can be identified, thereby providing more cost effective solutions to onshore and offshore installations. This paper describes briefly the concepts of sound intensity, the current state of standards and some aspects of measurement technique. Case histories of the use of sound intensity instrumentation in a variety of situations, relevant to gas turbine engineering, will be described. This will include laboratory and field based investigations.