Two-Dimensional Simulation of Multiple-Acoustic-Wave Scattering by a Human Body Model Inside an Acoustic Enclosed Space

This work presents the first study addressing two-dimensional numerical simulations of acoustic wave scattering involving a simplified human body model placed inside an enclosed cabin. The simulations utilise the µ-diff backscattering algorithm in MATLAB, which is suitable for modeling frequency-domain interactions with multiple scatterers under penetrable boundary conditions. The body is represented as a cluster of penetrable, tangent circular cylinders with acoustic properties mimicking muscle, fat, bone, and clothing layers. Hidden PVC cylinders are embedded to simulate concealed objects. Several configurations were examined, varying the number of PVC inclusions (two to four), the frequency range, and the presence of an absorbing cabin wall. Sound pressure level (SPL) distributions around the body and at a 1 m distance were analysed. Polar plots reveal distinct differences between the baseline body model and those incorporating PVC inclusions. The most pronounced effects occur near 160 Hz, where an absorbing wall is present within the acoustic enclosure. The presence of an absorbing wall modifies wave behaviour, producing enhanced directional attenuation. The results demonstrate how object composition, spatial arrangement, and enclosure geometry influence acoustic backscattered fields. These findings highlight the potential of wave-based numerical modelling for detecting concealed items on the human body in confined acoustic environments, supporting the development of non-invasive security screening technologies.