Active flow control becomes more and more important in many aerospace applications to
meet future economic and environmental requirements. Fluidic oscillators used for flowcontrol
are already introduced to the scientific community and their stable and robust operation is
very well known. The unsteady excitation effects up to frequencies of several kHz and the
reduced mass flow requirements are beneficial compared to steady blowing concepts. The
object of investigation is the well-known oscillator design developed at the Institute of Jet
Propulsion. The working principle of this actuator is based on two feedback loops and two
outlet holes perpendicular to the oscillator plane, generating a high frequency pulsed blowing.
This concept features a stable and predictable operation as well as the integration into thin
geometries, for instance turbomachinery blades. The scope of this paper are experimental
investigations of selected geometric design parameters and their influence on the oscillator
performance. The parameters examined in detail are the width of the actuator’s inlet nozzle,
oscillator’s channel height, feedback loop length, and linear scaling of the entire geometry. The
experiments were carried out at different ambient pressures levels, to cover the full pressure
spectrum of turbomachinery operation and flight applications. Depending on the parameter
variation and operating point, the range of one actuator is between 2 to 400 mg/s in mass
flow, covering pressure ratios from little above 1 to 8, and showing maximum frequencies
up to 14 kHz. The ambient pressure level is varied between atmosphere (950hPa) and 50hPa
absolute pressure. With the presented results a target-oriented design for a specific flow control
application in terms of mass flow rate, pressure ratio, and frequency spectrum can be derived.
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