Patent ID: 8152934

Claim:
A method for washing an aerofoil of a gas turbine engine having a principal and rotational axis using a multi-nozzle dispenser, the aerofoil comprising: a fan blade, a compressor blade or vane, or an outlet guide vane, the aerofoil having a suction surface and a pressure surface, the suction and pressure surfaces having a curve between a leading edge and a trailing edge and a twist between a blade tip and a blade root region, the multi-nozzle dispenser comprising: an elongated hollow body defining a fluid gallery within the hollow body, the hollow body having an axis extending a length of the hollow body; a plurality of nozzles located along the length of the hollow body connected to the fluid gallery so that washing fluid can flow through the fluid gallery and then into the nozzles during use; and at least a first nozzle and a second nozzle being angled at different angles about the hollow body axis and being arranged to eject a washing fluid at different angles relative to said rotational axis and, in use, each nozzle ejects said washing fluid onto different parts of the pressure surface or suction surface, wherein the first nozzle is angled such that a washing fluid jet impinges upon the pressure surface or the suction surface at more than 75 degrees to the surface, and the second nozzle is angled such that a washing fluid jet impinges upon the same pressure surface or suction surface as the first nozzle and at more than 75 degrees to the pressure surface or suction surface, wherein the hollow body comprising a plurality of segments, at least two of the segments having at least one nozzle mounted thereon and being rotatably mounted so that the rotatable segments can each be independently rotated and so that the rotatable segments can be rotated to change the angles of the first and second nozzles about the hollow body axis; said method comprising: locating said multi-nozzle dispenser into said gas turbine engine; angling the first nozzle and supplying washing fluid to the first nozzle so that the washing fluid jet impinges upon the pressure surface or suction surface at more than 75 degrees to the pressure surface or suction surface; and angling the second nozzle and supplying washing fluid to the second nozzle so that the washing fluid jet from the second nozzle is ejected onto a different part of the same pressure surface or suction surface than the washing fluid jet ejected from the first nozzle impinges and at more than 75 degrees to the pressure surface or suction surface.