Bleed assembly for a gas turbine engine
A bleed assembly for a gas turbine engine is provided. The assembly includes: a duct having an inlet and an outlet; a bleed valve that controls the flow of bleed fluid into the inlet; and a dome-shaped diffuser screen which covers the outlet. The diffuser screen has a plurality of through-holes for passage of the bleed fluid. Each through-hole has one or more nearest-neighbour through-holes at a nearest-neighbour spacing. At the periphery of the diffuser screen, the average nearest-neighbour spacing of the through-holes at a given radial distance from the centre of the diffuser screen increases with increasing radial distance.
1. A bleed assembly for a gas turbine engine, the assembly comprising:
a duct having an inlet and an outlet,
a bleed valve that controls the flow of bleed fluid into the inlet, and
a dome-shaped diffuser screen which covers the outlet, the diffuser screen having a plurality of through-holes for passage of the bleed fluid, each through-hole being adjacent one or more neighbouring through-holes,
wherein the through-holes are arranged in concentric rings around the centre of the diffuser screen, with the spacing between neighbouring through-holes being uniform within each ring,
wherein all of the through-holes have the same diameter, and
wherein, in a region of the diffuser screen near a periphery of the diffuser screen, for rings of successively greater diameter, the spacing between neighbouring through-holes within each ring is increased.
2. A bleed assembly according to claim 1 which bleeds fluid from a compressor of the engine.
3. A gas turbine engine having one or more bleed assemblies according to claim 1 .