Surface igniter cooling system

A torch igniter for a combustor of a gas turbine engine, the torch igniter comprising:

• a combustion chamber oriented about an axis, the combustion chamber having an axially upstream end and an axially downstream end defining a flow direction through the combustion chamber, along the axis;
• a cap defining the axially upstream end of the combustion chamber and oriented about the axis, wherein the cap is configured to receive a fuel injector and a glow plug;
• a tip defining the axially downstream end of the combustion chamber;
• an igniter wall extending annularly from the cap to the tip and defining a radial extent of the combustion chamber;
• a structural wall coaxial with and surrounding the igniter wall;
• an outlet passage defined in part by the igniter wall within the tip, wherein the outlet passage is fluidly connected to the combustion chamber;
• a glow plug housing configured to receive the glow plug and allow an innermost end of the glow plug to extend into the combustion chamber, the glow plug housing extending through the structural wall and the igniter wall at the cap;
• and
• a cooling system comprising:
• an air inlet formed within an exterior of the structural wall, the air inlet configured to intake a flow of air from a compressor section of the gas turbine engine;
• a first cooling channel extending between the structural wall and the igniter wall and fluidly connected to the air inlet;
• a second cooling channel extending through the structural wall at the glow plug housing and fluidly connected to the first cooling channel, the second cooling channel configured to accept the flow of air from the first cooling channel and direct the flow of air around the glow plug housing;
• and
• a third cooling channel fluidly connected to the second channel, the third cooling channel configured to accept the flow of air from the second cooling channel and direct the flow of air towards the axially upstream end of the cap before turning towards the axially downstream end and directing the air towards the combustion chamber through an air swirl hole extending through the igniter wall, transverse to the axis.