A control framework for wavepackets in turbulent jets using time-domain transfer functions

Resumo

© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.The mechanism of sound generation in the downstream direction of jets is often associated with large-scale structures, or wavepackets. These are often modelled using frequency-domain models based on the linearisation of the Navier-Stokes system. A closed-loop control formulation requires a time-domain model in order to calculate appropriate gains between sensors and actuators so as to minimise a given objective. In the present work, we address how such a control scheme can be developed using time-domain transfer functions, derived from corresponding frequency-domain models. We first exemplify the application of the present technique for a simplified 1D problem based on the nonlinear Burgers’ equation. The proposed method is then applied for time-domain transfer functions obtained using wave-packet models for jets, as an attempt to control large-scale structures in such flows and consequently reduce their sound radiation.