Combustor for a gas turbine

A combustor for a gas turbine, the combustor extending along a centre axis (Y) and comprising a combustion chamber having an inlet;

• the combustion chamber inlet defined by a burner comprising:
• a pilot burner section centred on the centre axis (Y) and which defines a fuel delivery conduit having an inlet for fluid communication with a fuel source;
• and
• a fuel injector in fluid communication with the fuel delivery conduit;
• a swirler section comprising vanes which extend radially outwards from the pilot burner section;
• a main burner section which extends radially outwards from, and surrounds, the swirler section;
• the pilot burner section is spaced apart from the main burner section to define an annular swirl flow path extending therebetween, the annular swirl flow path comprises an upstream plane and an exit plane;
• the main burner section defining a plurality of pre-mixing flow passages which each extend from a pre-mixing flow passage inlet on an inlet face of the main burner section to a premixing flow passage outlet on an outlet face of the main burner section;
• the main burner section further comprising a fuel manifold, each of the pre-mixing flow passages being provided with a fuel injector in flow communication with the fuel manifold;
• the fuel manifold being in flow communication with the fuel delivery conduit in the pilot burner section via a fuel flow passage which extends through the swirler section;
• wherein the pre-mixing flow passages are grouped in rows which extend radially away from the centre axis (Y), with radially extending passages of the manifold extending between the rows, wherein fuel injectors of a first subset of the premixing flow passages are located at a first distance XI from the inlet face of the main burner section, and fuel injectors of a second subset of the pre-mixing flow passages are located at a second distance X2, greater than the first distance XI, from the inlet face of the main burner section,
• wherein the fuel injectors in radially inner pre-mixing flow passages are located at the first distance XI from the inlet face of the main burner section, wherein the fuel injectors in radially outer pre-mixing flow passages are provided the first distance XI from the inlet face of the main burner section;
• and wherein the fuel injectors in the pre-mixing flow passages between the radially inner pre-mixing flow passages and the radially outer pre-mixing flow passages are located at the second distance X2 from the inlet face of the main burner section.