초록 ▼

A swept fan blade design for the low pressure compressor rotor or fan rotor stage of a ducted fan gas turbine engine has a leading edge swept forward near the hub up to a first radial height, then rearward up to second radial height and finally is swept forward again up to the blade tip. The aerodyn

A swept fan blade design for the low pressure compressor rotor or fan rotor stage of a ducted fan gas turbine engine has a leading edge swept forward near the hub up to a first radial height, then rearward up to second radial height and finally is swept forward again up to the blade tip. The aerodynamic effect is to produce a mid-height bias to the airflow enabling the tip region to be given increased twist and to possess increased resistance to foreign object damage. The design also provides a rear radial blade stacking axis to help reduce internal stresses due to centrifugal forces.

대표청구항 ▼

[ What is claimed is:] [1.] A fan stage of a ducted fan gas turbine engine, comprisinga fan casing having an inner duct wall which in a fan rotor region is convergent in the downstream direction; anda fan rotor including a multiplicity of swept fan blades spaced apart around a hub mounted concentric

[ What is claimed is:] [1.] A fan stage of a ducted fan gas turbine engine, comprisinga fan casing having an inner duct wall which in a fan rotor region is convergent in the downstream direction; anda fan rotor including a multiplicity of swept fan blades spaced apart around a hub mounted concentrically with respect to the fan duct, each of said swept fan blades having a tip profile which in revolution is convergent so as to substantially correspond to the convergent duct wall, a leading edge of variable sweep angle which varies with increasing blade height or distance from the axis of rotation, said sweep angle having a forward sweep angle in a first height region between the root and a first intermediate radius, a rearward sweep angle in an intermediate height region between the first intermediate radius and a second intermediate radius, a forward sweep angle in a third height region between the second intermediate radius and the tip of the blade, a stagger angle which increases progressively with blade height.