Three-dimensional computation of a synthetic jet in quiescent air

An unsteady Reynolds-averaged Navier-Stokes solver, WIND, is employed to capture the flowfield features of a synthetic jet pulsing into the quiescent air, case 1 of NASA Langley Research Center Workshop: "CFD validation of synthetic jets and turbulent separation control," held at Williamsburg, Virginia in March 2004. Both 2-D and 3-D simulations of this case have been performed by employing the appropriate boundary conditions at diaphragm of the actuator. It should be noted that the computations reported in this paper strictly follow the guidelines of the workshop in terms of all the parameters and modeling issues such as grid resolution, time step, boundary conditions, turbulence modeling, etc. Furthermore, to authors' knowledge, this is the only paper among the workshop participants reporting the 3-D simulations for this case. Comparisons are made with the experimental data; fair agreement is obtained. It is shown that the unsteady Reynolds-averaged Navier-Stokes simulations are capable of predicting the overall features of the oscillatory synthetic jet flowfield; however, noticeable discrepancies remain between the computations and the experimental data.