This paper puts forth several closure models for the proper orthogonal decomposition (POD) reduced order modeling of fluid flows. These new closure models, together with other
standard closure models, are investigated in the numerical simulation of the Burgers equation.
This simplified setting represents just the first step in the investigation of the new closure models.
It allows a thorough assessment of the performance of the new models, including a parameter
sensitivity study. Two challenging test problems displaying moving shock waves are chosen in the
numerical investigation. The closure models and a standard Galerkin POD reduced order model
are benchmarked against the fine resolution numerical simulation. Both numerical accuracy and
computational effciency are used to assess the performance of the models.