Spatial Filtering for Reduced Order Modeling
For researchers in computational fluid dynamics, this work offers an incremental improvement to regularized ROMs by introducing a new filter variant.
This paper numerically investigates spatial filtering for reduced order models, proposing a new ROM differential filter and testing it on flow past a cylinder at Re=760, showing improved accuracy over standard methods.
Spatial filtering has been central in the development of large eddy simulation reduced order models (LES-ROMs) and regularized reduced order models (Reg-ROMs), In this paper, we perform a numerical investigation of spatial filtering. To this end, we consider one of the simplest Reg-ROMs, the Leray ROM (L-ROM), which uses ROM spatial filtering to smooth the flow variables and decreases the amount of energy aliased to the lower index ROM basis functions. We also propose a new form of ROM differential filter and use it as a spatial filter for the L-ROM. We investigate the performance of this new form of ROM differential filter in the numerical simulation of a flow past a circular cylinder at a Reynolds number $Re=760$.