Active flow control devices and applications received a lot of attention in the recent three decades. While synthetic jets were the preferred technique during the early stages of this practice, fluidic oscillators, also called sweeping jets actuators, were recently in the focus of several research and engineering projects. These actuators bring in the advantages of no-moving-parts and high amplitude signal. However, their control is not straight forward and many times the exact nature of their output is not fully comprehended.
A combined experimental and numerical-simulation study, towards improved understanding of the operation principles, control and output of such a device is currently conducted by US Army AFDD, Tel-Aviv University and Rafael. The current talk focuses on the simulation aspects of this effort.
The internal flow mechanism of a suction and blowing (SOAB) device wasnvestigated using Large Eddy Simulation. The necessity of this level of simulation was queried, followed by comparison with measurements. The simulation results were then utilized to construct a set of functional-fit velocity profiles, to be used as time-dependent boundary conditions for the oscillatory blowing.
Towards implementation of a bank of actuators in a turbulent boundary layer, the separated effects of the actuators output, like suction alone, were investigated within a laminar and turbulent boundary layers. Large eddy simulation was the tool employed for this task also, coupled with wind-tunnels measurements. Interesting aspects of shear enhancement, interaction between suction holes wakes and onset of turbulence were observed.