Anti-aliasing for integrated LES-RANS computations

The increasing complexity of flow problems computed with numerical methods calls for the usage of hybrid approaches of Reynolds-averaged Navier Stokes (RANS) flow solvers and Large eddy Simulations (LES). Many flow solvers are developed using either RANS or LES. One possibility to combine these approaches is to let these separate flow solvers run simultaneously and exchange information at the interface. However, since the LES flow solver operates usually with a much smaller time-step, the data has to be sampled in order to provide data for the RANS flow solver. In the sampling process aliasing errors can occur. This study investigates possibilities in order to suppress aliasing errors while keeping the amplitude and phase of the long wave spectrum unharmed.