Numerical Investigation of a Shielded Chevron Nozzle

[摘要] Reynolds-Averaged Navier-Stokes simulations have been performed on a three-stream invertedvelocity profile nozzle with and without various configurations of chevrons attached.The nozzle was mounted on a planform to imitate an engine mounted above a wing, shieldingground observers from engine noise. Several chevron designs intended to aggressively mix thejet and move noise sources upstream for shielding were examined to investigate their effects onnoise and thrust. Numerical results for the baseline nozzle and one chevron configuration werecompared with far-field noise and particle image velocimetry data obtained in NASA GlennResearch Center’s Aero-Acoustic Propulsion Laboratory. A configuration in which chevronsalternate penetration into the primary stream and tertiary fan stream was explored using theModern Design of Experiments approach. Short, high-penetration chevrons demonstrated asignificant noise reduction for a relatively small thrust penalty.

[发布日期] 2019-01-07

[学科分类] 声学和超声波

[关键词] AEROACOUSTICS;AERODYNAMIC NOISE;DRAG REDUCTION;EFFECTIVE PERCEIVED NOISE LEVELS;ENGINE NOISE;JET AIRCRAFT NOISE;NAVIER-STOKES EQUATION;NOISE INTENSITY;NOISE REDUCTION;PARTICLE IMAGE VELOCIMETRY;PENETRATION;REYNOLDS AVERAGING;SHIELDING;SUPERSONIC TRANSPORTS;VELOCITY DISTRIBUTION