Framework for linear benchmark problems in computational acoustics

Solutions to the partial differential equations that describe acoustic problems can be found by analytical, numerical and experimental techniques. Within arbitrary domains and for arbitrary initial and boundary conditions, all solution techniques require certain assumptions and simplifications. Mostly, it is difficult to estimate the precision of a solution technique. Due to the lack of a standardised process to quantify and report the performance of the solution technique, a variety of ways exists to discuss the results with the scientific community. Moreover, the absence of general reference results does hamper the development of validating newly developed techniques. Over the years, many researchers in the field of computational acoustics have therefore expressed the need and wish to have available common benchmark cases. This contribution is intended to be the start of a long term project, about creating benchmarks in the entire field of computational acoustics within the EAA community. A framework of classifying acoustic benchmark cases is suggested and as a first step, this paper is limited to the class of linear acoustic cases. Within these cases, different categories are defined as eigenvalue problems, time-domain problems and time-harmonic problems. Among the other categories to be distinguished within the linear cases are interior and exterior problems, 2d and 3d problems, and problems with scattering or radiating boundary conditions. Furthermore, a way of reporting on the used solution technique (as the number of operations, memory requirements and accessibility of the numerical code) and on reporting the results for the selected benchmark case, is suggested. Three problems have been defined and they will demonstrate how the benchmark cases are intended to be used.