Abstract
The usual approach to the characterisation of exhaust systems, based on acoustic pressure measurements in different position along the exhaust line, is not always adequate as it has proved to be sensitive to the measuring position. Consequently, an experimental technique has been developed to measure acoustic intensity and power in ducts with a gas flow.
Pressure measurements taken in two adjacent positions have been processed, taking into account the mean flow velocity, to obtain progressive, regressive and total acoustic intensity. This paper describes this technique as well as its application on mufflers, exhaust lines mounted on Pulsatore and exhaust lines excited by firing engine.