Combustor with a variable volume primary zone combustion chamber

A combustor for a gas turbine, the combustor comprising:

• a combustor liner including an outer liner and an inner liner, a combustion chamber being defined between the outer liner and the inner liner, the combustion chamber including a primary combustion zone defined between the outer liner and the inner liner at an upstream end of the combustion chamber;
• an outer liner expanded primary volume portion extending circumferentially about a combustor centerline axis;
• and
• a secondary outer liner portion extending circumferentially about the combustor centerline axis,
• wherein the secondary outer liner portion is movable to adjust a volume of the primary combustion zone by opening and closing access to the outer liner expanded primary volume portion so as to increase and to decrease the volume of the primary combustion zone.