Numerical Modeling and Validation of the Flow in a Fluidic Oscillator

Abstract

A fluidic actuator is a device, which only needs one fluid supply to generate a self-induced and self-sustaining oscillating jet at its outlets. The present study investigates numerically the flow dynamics of a fluidic oscillator operated with water. Simulation results are validated with experimental data obtained with PIV and time-resolved pressure measurements. The numerical simulations are based on unsteady Reynolds-averaged Navier-Stokes equations (URANS) considering a turbulent, incompressible, and isothermal flow. Beforehand, a sensitivity analysis regarding the turbulence closure, the spatial grid solution, and the outlet geometry was conducted. In addition, to gain a deeper understanding of the flow dynamics a modal analysis is provided. It was found that the two-dimensional simulation employing the SST was sufficient to describe the flow field and dynamics qualitatively as well as quantitatively. However, nonlinear effects could only be observed in the threedimensional computations.