Inverted upstream and high bypass ratio turbojet engine with a downstream fan

摘要

PURPOSE: To reduce a cross-sectional area as well as overall dimensions while obtaining a high by-pass ratio by providing two separate overlapped channels for cold air. CONSTITUTION: An engine is furnished with two separate overlapped channels for cold air. A first cold air channel has an air intake port E1 common with a first air current through an upstream fan 1 and to a gas generator and two crescent/outlets S1 set on the outside sideward of an outlet S2 from a downstream fan 12. Additionally, a second cold air channel has two crescent air intake ports E2 set on the outside sideward of the air intake port E1, a ring passage 27 starting from the air intake port E2 and in which the downstream fan 12 is set and an outlet S2 from the downstream fan 12. The upstream fan 1 and the downstream fan 12 have a high by-pass ratio by the two channels. Additionally, as a part of the two channels is formed in a nacelle structural body, it is possible to reduce overall dimensions and a cross-sectional area of the engine.