Near-field sound radiation of fan tones from an installed turbofan aero-engine

Fan Flow Deflection for Supersonic Turbofan Engines

We present an initial parametric investigation of fan flow deflectors for suppressing noise from supersonic turbofan engines. Realistic exhaust geometry and flow conditions for bypass ratio 2.7 were simulated in a subscale experiment. The study encompassed acoustic measurement and mean velocity surveys. The deflectors comprised internal vanes with both symmetric and cambered airfoil sections an...

Sound Radiation Analysis of Automobile Engine Covers

A methodology to study the sound radiation of engine valve covers is presented. The analysis process uses a nonlinear static simulation followed by a steady state dynamics simulation to determine the sound pressure field due to the vibration of the engine cover. The effects of assembly loads are included. The methodology is demonstrated with two representative engine valve covers using acoustic...

Fan Flow Deflection in Simulated Turbofan Exhaust

Fan flow deflection for jet noise reduction was applied to subscale nozzles simulating the geometry and exhaust conditions of separate-flow turbofan engines. Two types of deflectors were tested, one comprising two pairs of vanes internal to the fan duct and the other consisting of a wedge positioned outside the fan duct. The noise reduction achieved by the vanes was strong in the downward direc...

Future Aero Engine Designs: An Evolving Vision

Optimization of Fan Flow Deflection for Supersonic Turbofan Engines

This study involves the application of fan flow deflectors for suppression of jet noise from low-bypass turbofan engines for next-generation supersonic aircraft. Experiments using canonical vane deflectors seek to establish correlations between aerodynamics, distortion of the mean velocity field in the jet plume, and noise reduction. The maximum radial velocity gradient, as a function of axial ...