Experimental and Computational Investigation of Using Passive Sweeping Mist Jet Film Cooling via Fluidic Oscillators in the Gas Turbine Application

As the energy industry transitions to cleaner fuels like hydrogen, the resulting higher flame temperatures pose significant challenges for gas turbine cooling. Mist-enhanced film cooling using sweeping jets, generated by passive fluidic oscillators, offers a promising solution by providing wider and more uniform coolant coverage. This study combines computational and experimental (using Particle Droplet Phase Analyzer) approaches to evaluate sweeping mist jet performance. Simulations were conducted under laboratory conditions to investigate the influence of droplet wall boundary conditions—reflect, trap, and wall-film—on cooling effectiveness and droplet dynamics. The wall-film model, motivated by observed liquid streaks, demonstrated the best agreement with experiments. Additional simulations at elevated pressures and temperatures assessed the viability of mist cooling under realistic turbine conditions. The results showed that liquid droplets coalesce inside fluidic oscillators, producing larger droplets and achieving more uniform and more extended downstream cooling.