METHOD AND MIXER FOR REDUCING NOISE FROM TURBO-FAN ENGINE

摘要

PROBLEM TO BE SOLVED: To reduce noise by forming pairs of auxiliary lobes of sine shape at the peripheral parts on the radially outside of a plurality of main lobes circumferentially arranged and axially extended in a mixer for mixing concentric inner and outer flow in a turbo-fan engine. SOLUTION: In a turbo-fan engine with a nacelle, air flows in from the front part of a jet engine and passes a fan so as to be separated into main flow and bypass flow, and two flow stream are mixed by a mixer 7. The mixer 7 is a hollow duct and has a plurality of main lobes 8 and paired auxiliary lobes 9 provided radially outward of the respective main lobes 8. A space between a pair of auxiliary lobes 9 is formed into an auxiliary shoot 11, and part of fan flow 4 is turned in a center direction, while part of core flow 6 is turned to the outside. Both main shoots 10 and auxiliary sheets 11 act as pipes for making the fan flow 4 flow toward the center direction.