Three-Dimensional Active Flow Control Drag Reduction Studies Over a Bluff Body Using a Coupled Lattice Boltzmann-Navier-Stokes Methodology

Abstract

A coupled Lattice Boltzmann – Navier-Stokes methodology in three dimensions is implemented for modeling flow control phenomena. A one cell overlap between the Lattice Boltzmann (LB) and Navier-Stokes (NS) grids is used to exchange information between the two solvers. Flow over a circular cylinder has been chosen as the case study for the present drag reduction studies. A comparison of the baseline flow over a two-dimensional and threedimensional cylinder has been performed. The difference in the flow phenomena between the two cases has been examined. The coupled methodology has subsequently been applied to the flow over a 3-D circular cylinder with a synthetic jet device for drag reduction. The LB solver is used to resolve the flow physics at the small length scales in the synthetic jet region and the NS solver is used to model the rest of the flow domain. A drag reduction of 8.5 percent is observed in the synthetic jet case compared to the baseline case without active flow control.