Force Field Estimation with Data Assimilation Techniques

Abstract

Plasma actuators (PA) generate an electrohydrodynamic force density in the air near an electrically insulating surface where electrodes are located. This actuation produces a spatiotemporal force distribution that induces mean and fluctuating velocity fields in the surrounding fluid media. To obtain these force fields, it appears beneficial to develop tools that can utilize experimental velocity field data. To this end, we propose a new force estimation process based on a data assimilation technique implemented with a Direct Numerical Simulation (DNS) code. The proposed method is tested using synthetic velocity flow field data produced by a computational fluid dynamics code. The proposed optimization method starts with an initial estimate of the force field derived from velocity data and an approximation of the Navier-Stokes equations. Through an iterative process, the considered strategy reduces the discrepancy between experimental and simulated vorticity data. The results obtained demonstrate that the data assimilation approach proves to be a quite satisfactory tool for recovering the dynamics of the force density produced by the actuator.