DYNAMICAL MODELING OF LARGE SCALE COHERENT STRUCTURES IN THE WAKE OF A WALL MOUNTED FINITE CYLINDER

The Extended Proper Orthogonal Decomposition (EPOD) was used to estimate the coherent structures in the wake of a wall mounted finite cylinder from the surface fluctuating pressure. To show the surface pressure is actually a good indicator, the method was first applied to the Large Eddy Simulation (LES) results, from which the instantaneous velocity and pressure data were available in the whole domain. Subsequently, the method was applied to planar Particle Image Velocimetry (PIV) measurements for which only the pressure at discrete points at the cylinder side faces were taken. Even though a part of the correlation is lost due to the experimental limitations, the amplitude modulations and base flow variations around the average limit cycle were recovered and great improvements were achieved over the traditional phase averaging approach.