Patent attributes
A fan blade (26) comprises a leading edge (44), a trailing edge (46), a concave wall portion (50) extending from the leading edge (44) to the trailing edge (46) and a convex wall portion (52) extending from the leading edge (44) to the trailing edge (46). A flexible wall (56) is arranged within the fan blade (26) to partially define a plurality of chambers (60) with an internal surface (54) of the convex wall portion (52). The flexible wall (56) is arranged substantially parallel to the internal surface (54) of the convex wall portion (52) and a plurality of walls (64) connect the internal surface (54) of the concave wall portion (50) and the flexible wall (56). The chambers (60) contain a fluid. The chambers (60) are interconnected by apertures (62) such that in operation deflection of the flexible wall (56) by vibrations of the fan blade (36) produce a flow of fluid between the chambers (60) through apertures (62), which is restricted by the apertures (62) to damp vibrations of the fan blade (26).
