Accurate model reduction of transient and forced wakes

Some applications of a precise method to model the transient dynamics of large scale structures in the laminar flow past a bluff body are presented. The flow is described using empirical eigenfunctions obtained by “proper orthogonal decomposition” and the models are constructed projecting the Navier–Stokes equations onto such eigenfunctions. The linear terms in the expansion coefficients as well as in the control inputs are adjusted to exactly mimic some reference solutions. Applications shown are relative to the development of flow instabilities leading to vortex shedding and the dynamics of the vortex wake under external actuation.