Computer-Aided Liner Optimization For Broadband Noise

In this article the attenuation of broadband noise in an acoustically-lined circular-section duct is investigated. The aim is to predict how an axially segmented liner in∞uences the attenuation of broadband noise in an aero-engine intake. The sound fleld is modelled using a multi-modal representation, assuming an ensemble of uncorrelated modes over a wide range of frequencies. An optimization procedure based on a Response Surface Model is used to investigate the optimum uniform and axially-segmented acoustic liner that maximizes the attenuation of broadband noise. An approximate calculation of the Perceived Noise Level (PNL) is used for the objective function. In this article the beneflt of using an axiallysegmented liner instead of a uniform liner to attenuate broadband noise is demonstrated.