Fluidic Oscillators in Impingement Jet Cooling: A Novel Configuration for Realizing Sweeping Jets

Abstract This study examines integrating fluidic oscillators into a multi-jet impingement cooling system for turbomachinery, aiming to enhance heat transfer while reducing coolant requirements. The investigated configuration features multiple in-line impingement jets within a square channel under self-induced cross-flow. Fluidic oscillators, placed downstream of select jets, induce sweeping motions to disrupt the thermal boundary layer. Both unsteady Reynolds-averaged Navier–Stokes simulations using DLR’s TRACE code and high-speed particle image velocimetry measurements capture the unsteady flow dynamics. Additional proper orthogonal decomposition-based analysis reveals how oscillators influence jet stabilization and cooling uniformity. Results show that a fluidic oscillator arranged on the hole plate stabilizes downstream jets without degrading overall heat transfer, while one placed on the target plate does not yield similar benefits. These findings offer new insights into optimizing impingement cooling via compact, passive fluidic devices.