  Vortex shedding around circular cylinders is a well known and studied
phenomenon that appears in many engineering fields. A Reduced Order Model (ROM)
of the incompressible flow around a circular cylinder is presented in this
work. The ROM is built performing a Galerkin projection of the governing
equations onto a lower dimensional space. The reduced basis space is generated
using a Proper Orthogonal Decomposition (POD) approach. In particular the focus
is into (i) the correct reproduction of the pressure field, that in case of the
vortex shedding phenomenon, is of primary importance for the calculation of the
drag and lift coefficients; (ii) the projection of the Governing equations
(momentum equation and Poisson equation for pressure) performed onto different
reduced basis space for velocity and pressure, respectively; (iii) all the
relevant modifications necessary to adapt standard finite element POD-Galerkin
methods to a finite volume framework. The accuracy of the reduced order model
is assessed against full order results.
