Abstract: In a method of forming a pattern, a first pattern is formed over an underlying layer, the first pattern including main patterns and a lateral protrusion having a thickness of less than 25% of a thickness of the main patterns, a hard mask layer is formed over the first pattern, a planarization operation is performed to expose the first pattern without exposing the lateral protrusion, a hard mask pattern is formed by removing the first pattern while the lateral protrusion being covered by the hard mask layer, and the underlying layer is patterned using the hard mask pattern as an etching mask.

Abstract: A fuel spray nozzle, for atomising liquid fuel in gas, including: an gas passage; a liquid fuel passage; a swirler provided in the gas passage and including vanes such that, when gas passes through the gas passage, the swirler produces a jet flow of gas from between adjacent vanes and a turbulent flow of gas in the wake of each vane; a prefilming surface for receiving liquid fuel from the liquid fuel passage, and gas from the gas passage, wherein the prefilming surface includes areas that receive jet flow of gas from the gas passage, in use; wherein the fuel spray nozzle is configured to direct the liquid fuel passing through the liquid fuel passage to the areas on the prefilming surface that receive a jet flow of gas from the gas passage.

Abstract: A lean burn fuel injector has a head which has a coaxial arrangement of an inner pilot air-blast fuel injector and an outer main air-blast fuel injector. The pilot fuel injector comprises coaxially arranged inner and outer air swirler passages. The main fuel injector comprises coaxially arranged inner and outer air swirler passages. A first splitter is arranged between the passages. The first splitter has a conical divergent downstream portion. A second splitter is arranged radially within and spaced from the first splitter. The second splitter has a conical convergent portion and a conical divergent downstream portion. The downstream end of the second splitter is upstream of the downstream end of the first splitter. A connecting member connects the downstream end of the second splitter and the downstream portion of the first splitter upstream of the downstream end of the first splitter to form a sharp edge.

Abstract: A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.

Abstract: A lean burn fuel injector has a head which has a coaxial arrangement of an inner pilot air-blast fuel injector and an outer main air-blast fuel injector. The pilot fuel injector comprises coaxially arranged inner and outer air swirler passages. The main fuel injector comprises coaxially arranged inner and outer air swirler passages. A first splitter is arranged between the passages. The first splitter has a conical divergent downstream portion. A second splitter is arranged radially within and spaced from the first splitter. The second splitter has a conical convergent portion and a conical divergent downstream portion. The downstream end of the second splitter is upstream of the downstream end of the first splitter. A connecting member connects the downstream end of the second splitter and the downstream portion of the first splitter upstream of the downstream end of the first splitter to form a sharp edge.

Abstract: A lean burn fuel injector comprises a fuel feed arm and a fuel injector head. The fuel feed arm has a single pilot fuel supply passage and a single main fuel supply passage extending there-through. The fuel injector head has a coaxial arrangement of an inner pilot air-blast fuel injector and a coaxially arranged outer main air-blast fuel injector. The inner pilot air-blast fuel injector comprises a coaxial arrangement of a pilot inner air swirler passage and a pilot outer air swirler passage. The outer main air-blast fuel injector comprises a coaxial arrangement of a main inner air swirler passage and a main outer air swirler passage. The single main fuel supply passage is arranged to supply main fuel to the main inner air swirler passage. The single pilot fuel supply passage is arranged to supply pilot fuel onto the pre-filming surfaces in the pilot inner and outer air swirler passages.

Abstract: A fuel spray nozzle, for atomising liquid fuel in gas, including: an gas passage; a liquid fuel passage; a swirler provided in the gas passage and including vanes such that, when gas passes through the gas passage, the swirler produces a jet flow of gas from between adjacent vanes and a turbulent flow of gas in the wake of each vane; a prefilming surface for receiving liquid fuel from the liquid fuel passage, and gas from the gas passage, wherein the prefilming surface includes areas that receive jet flow of gas from the gas passage, in use; wherein the fuel spray nozzle is configured to direct the liquid fuel passing through the liquid fuel passage to the areas on the prefilming surface that receive a jet flow of gas from the gas passage.

Abstract: A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.

Abstract: A combustion chamber arrangement including an outer annular wall and an inner annular wall spaced from the outer annular wall. The inner annular wall includes a plurality of tiles. At least one of the tiles is secured to the outer annular wall by at least one stud and a cooperating nut. Each stud includes a head and a threaded portion extending from the head. The threaded portions extend through an aperture in the tile and an aperture in the outer annular wall. The head includes a plurality of spacers to space the head from an inner surface of the tile. An associated washer either has an aperture extending radially there-through or a slot extending radially along one of the surfaces of the washer to supply coolant over the stud or the space between the inner annular wall and the outer annular wall is arranged to supply coolant over the stud.