Reduced noise fan exit guide vane configuration for turbofan engines

Abstract

In a turbofan engine, the fan exit guide vanes in the bypass duct have the radially outermost 5% to 50% of their leading edge swept either forward or rearward at an angle of between 10° and 60° to reduce broadband noise. No more than 50%, but at least 5% of the full vane span is swept in that manner. Because most of the broadband noise is generated at the radially outermost portion of the vane, sweeping of the full length of the vane is not necessary. This allows use of a vane that takes up less axial length within the bypass duct and may weigh less than prior art swept vanes.