The continued development of quiet engines is now giving rise to situations where airframe noise is comparable with engine noise at approach. The landing gear is a major contributor to airframe noise, and this paper outlines the development of a prediction model for these components. The fundamental scaling laws for aerodynamic noise generated by solid bodies in a flow are well understood and so the essence of the new model is to refine the geometrical description of the landing gear and to take better account of such factors as the local flow velocity over individual components. The prediction model comprise four fundamental sources for various types of components on the landing gear, and included a number of directivity effects. It was used to predict flyover data for the A320 and A340 aircraft. The accuracy of both predictions was excellent around the overhead position, but was significantly reduced in the far forward and rearward arcs. This discrepancy arose from significant differences in the directivity of the flyover and wind tunnel data sets, the source of which is still unclear.
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