Combined Effects of External and Nozzle Exit Flows on the Jet Acoustic Power Levels of Chevron Nozzles for Transonic Aircraft

The issue of jet noise pollution from major airports has become increasingly significant. Recent research has indicated that incorporating a geometry-optimized chevron nozzle can effectively reduce jet acoustic power levels. Herein, we conduct a diagnostic investigation into the acoustic power levels of four different chevron nozzles. In silico studies are performed using a validated steady three-dimensional density-based k-ε turbulence model. Our findings reveal that among the four chevron nozzles (sharp, square, flat, and round edge), the implementation of a round-edged chevron proves to be the most effective design choice for mitigating jet noise in transonic aircraft. This design reduces the acoustic power level by 10% when compared to the base model of a classical high-subsonic/transonic nozzle (without chevron), while still maintaining the benefits of momentum thrust. The results of this study contribute to advancements in aero-acoustic research and provide valuable insights for the design optimization of chevron nozzles for transonic aircraft.