A POD APPROACH FOR TURBULENT FLOW CONTROL BY ELECTRO-HYDRODYNAMIC LARGE-SCALE STRUCTURES
Annotatsiya
With the aim of optimizing the electrostatic body force used to control a tur- bulent boundary-layer, a numerical reduced-order model is proposed for the turbulent flow field and the electric field. The reference configuration is a pressure-driven channel flow, in which the electrostatic body force is generated by ideal thin wires placed streamwise in the middle plane. As a first step, the current density field J, which governs the electrostatic force acting on the fluid, is parameterized by an approximate analytical field satisfying the same boundary conditions, to which an homogeneous representation based on proper or- thogonal decomposition (POD) is added. In this way, the optimization procedure operates with a reduced number of parameters, i.e. the approximate J and the coefficients of the retained POD modes. Then, a low-order model, again based on POD is proposed for the fluid dynamics, to obtain a simplified dynamical system in the form of a set of nonlinear ordinary differential equations. Finally, the procedure is completed by an inverse process that allows the electrostatic field to be recovered from the optimum current density dis- tribution. Accuracy and efficiency of each single step are evaluated by comparison with results given by standard numerical solvers.