The Effects of Compressibility on the Performance and Modal Structures of a Sweeping Jet Emitted from Various Scales of a Fluidic Oscillator

Investigations of fluidic oscillators, or sweeping jet actuators, have primarily been conducted within the incompressible flow regime, which limits accuracy estimating oscillator performance for compressible flows. The objective this study was to evaluate effects gas compressibility on a oscillator. A commonly used geometry (the Bray geometry) scaled five different sizes, 3D printed, and tested over range air rates. High-speed Schlieren images captured exiting custom MATLAB algorithms were calculate oscillation frequencies angles. spectral proper orthogonal decomposition (SPOD) method identify compare mode structures fields. All results compared using dimensionless parameters observe trends. showed that directly proportional rate, while angles inversely regardless scale size. angular velocities not rate size exhibited maxima evaluated ranges. For all symmetric across centerlines oscillators extended further beyond at higher These enable prediction performance, can significantly improve design process an application where may be used, such as aerospace applications, power generation, heat exchangers, medical devices.