Index of content:
Volume 125, Issue 4, April 2009
- AEROACOUSTICS, ATMOSPHERIC SOUND 
Finite difference time domain electroacoustic model for synthetic jet actuators including nonlinear flow resistance125(2009); http://dx.doi.org/10.1121/1.3081514View Description Hide Description
A lumped element electroacoustic model for a synthetic jet actuator is presented. The model includes the nonlinear flowresistance associated with flow separation and employs a finite difference scheme in the time domain. As opposed to more common analytical frequency domain electroacoustic models, in which the nonlinear resistance can only be considered as a constant, it allows the calculation of higher harmonics, i.e., distortion components, generated as a result of this nonlinear resistance.Model calculations for the time-averaged momentum flux of the synthetic jet as well as the radiated sound power spectrum are compared to experimental results for various configurations. It is shown that a significantly improved prediction of the momentum flux—and thus flow velocity—of the jet is obtained when including the nonlinear resistance. Here, the current model performs slightly better than an analytical model. For the power spectrum of radiated sound, a reasonable agreement is obtained when assuming a plausible slight asymmetry in the nonlinear resistance. However, results suggest that loudspeaker nonlinearities play a significant role as well in the generation of the first few higher harmonics.