Combustion section heat transfer system for a propulsion system

A propulsion system comprising:

• an annular inner wall and an annular outer wall, wherein the inner wall and the outer wall extend at least partially along a longitudinal direction and together define a combustion chamber therebetween, and wherein the inner wall and the outer wall together define, in part, a combustion chamber inlet and a combustion chamber outlet;
• a nozzle assembly disposed at the combustion chamber inlet, the nozzle assembly configured to provide a fuel and oxidizer mixture to the combustion chamber;
• a turbine nozzle coupled between the inner wall and the outer wall and positioned at the combustion chamber outlet, wherein the turbine nozzle defines a cooling circuit within the turbine nozzle;
• an inner casing disposed radially inward of the inner wall and an outer casing disposed radially outward of the outer wall, wherein each of the inner casing and the outer casing are coupled to the turbine nozzle;
• and
• a channel structure including a channel wall extending along the longitudinal direction and defining a first flowpath between the combustion chamber and the channel wall, wherein a second flowpath is defined between the channel structure the inner casing or the outer casing,
• wherein a primary flowpath is defined from the first flowpath to the cooling circuit to the second flowpath to the nozzle assembly then into the combustion chamber.