Computational Analyses of Offset-Stream Nozzles for Noise Reduction

摘要

Reynolds-averaged Navier-Stokes calculations were performed on two offset-stream-nozzle concepts for jet noise reduction. The first concept used an S-duct to direct the secondary stream to the lower side of the nozzle. The second concept used vanes to turn the secondary flow downward. The analyses were completed in preparation for a series of experimental tests in which noise and flowfield measurements would be made. The offset-stream nozzles demonstrated good performance and reduced the amount of turbulence on the lower side of the jet plume. The computer analyses proved instrumental in guiding the development of the final test configurations and giving insight into the flow mechanics of offset-stream nozzles. The computational predictions were compared with flowfield results from the jet-rig testing and showed excellent agreement.