Gas turbine combustor

A gas turbine combustor comprising:

• (a) an inner liner and an outer liner surrounding a center axis and that are concentric and cylindrical, and an end liner disposed between upstream ends of the inner liner and the outer liner, wherein the gas turbine combustor forms a combustion chamber that is an area surrounded by the inner liner, the outer liner, and the end liner,
• wherein the combustion chamber includes a primary combustion chamber disposed close to the end liner and a secondary combustion chamber disposed downstream of the primary combustion chamber, wherein the primary combustion chamber is annular and surrounds the center axis,
• and wherein an annular restrictor reducing the outer diameter of the primary combustion chamber is disposed between the primary combustion chamber and the secondary combustion chamber;
• (b) a swirling air flow forming device disposed to introduce combustion air into a vicinity of the end liner in the annular primary combustion chamber from outside and form a swirling air flow surrounding the center axis;
• (c) a fuel ejector disposed to eject fuel to the annular primary combustion chamber in the swirling direction of the swirling air flow to form a premixed swirling flow to form a tubular flame surface when ignited;
• and
• (d) an igniter disposed to ignite the premixed swirling flow of the swirling air flow and the fuel to form a tubular flame surface
• wherein the swirling air flow forming device includes
• an annular member disposed at an end close to the end liner in the inner surface of the outer liner to form the primary combustion chamber therein, wherein the annular member has a thickness greater than a thickness of the outer liner;
• and
• a combustion air hole penetrating an outer surface of the annular member in the swirling direction of the swirling air flow in the primary combustion chamber.