Abstract: A fuel-injection arrangement for a gas-turbine engine has distributed longitudinally along a pre-chamber portion of the combustion chamber a series of fuel-outlet holes configured such that a radial component of momentum of the fuel exiting the holes varies along the series of holes. To achieve this the holes are preferably differently sized along the trailing edge. Advantageously, the holes at the very upstream end of the pre-chamber portion have the smallest diameter, the size thereafter progressively increasing along the series. The size distribution may vary either continuously, or in stepped fashion. The direction of exit of the fuel from the outlets is preferably radial towards the central axis of the swirler. The variable-sized holes may be employed in a swirler upstream the main combustion chamber region and/or in an intermediate region between the swirler and the main chamber region.

Abstract: The combustor has three injection stages to supply fuel or a fuel/air mixture progressively to a pre-chamber or a main combustion chamber wherein the third injection stage comprises an elongated passage with an arrangement for introducing fuel into the passage. Preferably the passage extends alongside the combustion chamber and/or another passage for cooling air.

Abstract: A combustor for a gas-or liquid-fuelled turbine having a compressor to supply air to the combustor for combustion and cooling, comprises a radially inner member which defines a combustion chamber and a radially outer member, a passage for said air being defined between the inner member and the outer member so as to extend alongside the combustion chamber over at least part of the length thereof and a fuel/air mixer 14 being provided at the upstream end of the combustion chamber, the cross-sectional area of the passage between the two members increasing over at least part of the length of the passage in a direction from the downstream end to the upstream end of the combustion chamber, the passage having an inlet adjacent to the downstream end of the combustion chamber whereby air from the compressor enter the passage at the inlet, and flows in a direction toward the mixer.