On non-reflective boundaries for outdoor sound propagation using the discontinuous galerkin method

In environmental acoustics, sound propagates in open air and can be mathematically modelled in terms of a semiinfinite domain. The calculations for accurate numerical
solutions for outdoor acoustics are computationally heavy when the chosen computation domain is large enough to fulfil the Sommerfeld radiation condition. To lower the
computational cost, the domain must therefore be truncated to not significantly impact the numerical solution inside the domain and allow outgoing acoustic waves to leave the domain undisturbed. Various radiation conditions (sometimes considering the wind) have been developed to achieve this goal such as the Perfectly Matched Layer method. The aim of this study is to compare the accuracy of different non-reflecting boundaries using the high-order nodal discontinuous Galerkin finite element method (DG-FEM) for the case of an acoustic pulse propagating in a static and moving medium in an unstructured mesh. For each boundary treatment, the tunable parameters of the methods are defined to balance accuracy and computational cost.