ABSTRACT
Synthetic jet actuation is a very promising technique that demonstrates the great potential for separation control (Seifert et al. 1996; Crook et al. 1999), lift enhancement (Smith et al. 1998), heat transfer (Mahalingam and Glezer 2005), flow vectoring (Guo and Gary 2001), mixing enhancement (Chen et al. 1999), and transition delay (Rathnasingham and Breuer 1997b). The numerical simulation and optimization of synthetic jet flows have recently received considerable attention. The exact nature of any synthetic jet actuator can be determined (in principle) by simulating the precise three-dimensional (3-D) geometry, including all aspects of diaphragmmovement and deformation (see Chapter 5 for detailed
discussion of this approach). Note, however, that the full numerical simulation of both the cavity and exterior flowfields is extremely computationally expensive, which makes this approach impractical for analysis and optimization of synthetic jet flows. Indeed, the numerical solution of the cavity flow requires nearly the same number of grid points that are needed to solve the exterior flowfield. Furthermore, the Mach number in the problem varies from O(10-3) (near the diaphragm) to O(1) (in the exterior flow). The variation of the flow parameters from fully incompressible to fully compressible regimes and the presence of the moving boundary considerably increase the algorithm complexity. As a result, the computational cost associated with the 3-D unsteady Navier-Stokes model is generally too large,which indicates that reduced-ordermodelingof synthetic jets is critical, especially for design and optimization studies.
