RANS Analyses of Turbofan Nozzles With Internal Wedge Deflectors for Noise Reduction

摘要: Computational fluid dynamics (CFD) was used to evaluate the flow field and thrust performance of a promising concept for reducing noise at take-off dual-stream turbofan nozzles. The concept, offset stream technology, reduces jet observed on ground by diverting (offsetting) portion fan below core flow, thickening lengthening this layer between high-velocity observers. In study wedge placed in internal is as diverter. Wind, Reynolds averaged Navier–Stokes (RANS) code, analyze exhaust plume calculate nozzle performance. Results showed that diverts all lower side nozzle, turbulent kinetic energy observer reduced. This reduction should correspond noise. However, because diverted, upper exposed freestream, increased, creating an unintended source. blockage due mass proportional its blockage, overall consequently CFD predictions are very good agreement with experimental data, demonstrating RANS can accurately predict velocity fields. While initial design large scale did not meet or goals, identified areas improvement demonstrated be improve concept.