Auxiliary torch ignition

A gas turbine combustor assembly, comprising:

• a primary combustion chamber in fluid communication with a primary fuel injector and a primary air inlet;
• and
• a torch igniter coupled to the primary combustion chamber, the torch igniter comprising:
• an auxiliary fuel injector;
• an ignition source;
• and
• an igniter body carrying the auxiliary fuel injector and the ignition source, the igniter body comprising:
• an auxiliary combustion chamber having a side wall extending axially from a first end wall to a second end wall defining a fluid outlet leading to an outlet tube in fluid communication with the primary combustion chamber wherein a premixing cup resides in the auxiliary combustion chamber,
• an outer shell comprising a fluid inlet coaxially aligned with the outlet tube, and
• a fluid annulus defined by an inner surface of the shell and an outer surface of the auxiliary combustion chamber, the annulus directing an upstream fluid flow from the fluid inlet towards the first end wall,
• wherein at least a portion of the outlet tube comprises a distributed pattern of dilution apertures configured to route a first portion of the upstream fluid flow from the fluid annulus into a downstream flow of heated gas exiting the auxiliary combustion chamber through the outlet tube, and
• wherein at least a portion of the side wall comprises a distributed pattern of cooling apertures, with each of the cooling apertures extending obliquely through the side wall of the auxiliary combustion chamber, so as to cause a second portion of the upstream fluid flow entering an interior cavity of the auxiliary combustion chamber from the fluid annulus through the coding apertures to form a fluid film along an inner surface of the side wall.