This paper deals with the prediction of noise scattered by moving bodies. The objective is the understanding of the differences among predictions provided by the scattering formulations based on the integration of the wave equation for the velocity potential, the Lighthill equation, and the Ffowcs Williams and Hawkings equation for the pressure disturbance, when the scatterer is not at rest. Observing that these are all based on the same flow modelling assumptions, the discrepancies reside in the different influence of the nonlinear terms, typically neglected. Here, the focus is on the velocity potential-based approach. Extracting the first-order contributions from the nonlinear terms, a boundary-field frequency-domain formulation for the scattered potential is developed, as enhancement of the standard linear boundary integral approach. The influence of the additional field contributions is examined for different scatterer velocities, with the aim of assessing the domain of validity of the fully linear formulation and the rate of grow of the field contributions with increase of velocity, as well as to confirm that their inclusion tends to decrease the discrepancies with the alternative linear formulations. Specifically, the numerical investigation concerns the noise scattered by a moving, nonlifting wing, when impinged by an acoustic disturbance generated by a co-moving source.
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