Recent advances in computational aeroacoustics

There are intrinsic differences between the characteristics and the objectives of aeroacoustics problems and typical fluid dynamics problems. These differences are not addressed by computational fluid dynamics (CFD). They form some of the major challenges to computational aeroacoustics (CAA). Recent advances in CAA methodologies to meet those challenges are reviewed. They include the development of high resolution CAA methods, artificial selective damping and high quality numerical boundary conditions. One unique development in CAA that has no counterpart in CFD is the wave number analysis approach. Wave number analysis not only can yield an absolute error incurred in the use of a discretized computational method but also offers a way to develop optimized computation schemes. It is indispensable in analyzing dispersion and dissipation errors associated with wave propagation computations. To illustrate the impact of CAA on aeroacoustics, an example of CAA application will be briefly discussed. As CAA application expands in scope, new challenges to CAA emerge. Some of the more pressing challenges that may well chart the future development of CAA methodology are elaborated.