Patent ID: 6546731
Filing Date: 2003-04-15
Classification: F23R

Abstract:
A combustion chamber for a gas turbine engine, the combustion chamber comprising:a) upstream and downstream ends relative to a direction of combustion gas flow therethrough, b) an inner wall, c) an outer wall spaced apart from the inner wall such that confronting surfaces of the outer and inner walls do not abut each other, thereby to define a cavity between the walls, d) the outer wall having a plurality of impingement cooling holes therethrough connecting with the cavity, whereby, during operation of the engine, compressed air surrounding the chamber passes through the impingement holes to impinge on the inner wall, e) the inner wall having a plurality of effusion holes therethrough, whereby air effuses from the cavity between the inner and outer walls into the combustion chamber, there being a greater number of effusion holes than impingement holes, and f) the effusion holes being arranged in groups, each group comprising a plurality of the effusion holes substantially equally spaced apart from each other around a central effusion hole, each group of effusion holes having an impingement hole located in the outer wall such that air passing through the impingement hole impinges on the inner wall at a predetermined position offset relative to the central effusion hole within a boundary defined by the group of effusion holes, said impingement within the boundary being a first contact of the air with the inner wall after the air has passed through the impingement hole.