Acoustic liners of jet engines

Acoustic liners employing the Helmholtz resonator concept are commonly used in the intake duct of modern jet engines to reduce radiated noise. In response to reports of core failures, the possibility of acoustic loading as the source of these liner failures is investigated. Experimental data are used as input to a model for non-rigid cavity walls and the induced stresses analysed. An alternative, more robust, liner design utilizing viscous damping is proposed, and an analytical model developed and numerically validated against published data. A study of the key parameters leads to an improved configuration, the attenuating properties of which are compared to a typical liner.