Title: Ray-tracing semiclassical low frequency acoustic modeling with local and extended reaction boundaries,
Abstract: The recently introduced acoustic ray-tracing semiclassical (RTS) method is
validated for a set of practically relevant boundary conditions. RTS is a
frequency domain geometrical method which directly reproduces the acoustic
Green's function. As previously demonstrated for a rectangular room and weakly
absorbing boundaries with a real and frequency-independent impedance, RTS is
capable of modeling also the lowest modes of such a room, which makes it a
useful method for low frequency sound field modeling in enclosures. In
practice, rooms are furnished with diverse types of materials and acoustic
elements, resulting in a frequency-dependent, phase-modifying
absorption/reflection. In a realistic setting, we test the RTS method with two
additional boundary conditions: a local reaction boundary simulating a
resonating membrane absorber and an extended reaction boundary representing a
porous layer backed by a rigid boundary described within the Delany-Bazley-Miki
model, as well as a combination thereof. The RTS-modeled spatially dependent
pressure response and octave band decay curves with the corresponding
reverberation times are compared to those obtained by the finite element
method.