A combustion section for a gas turbine engine , the combustion section defining a radial direction, a circumferential direction, a longitudinal centerline extended along a longitudinal direction, and a forward direction toward a downstream end and an aft direction toward an upstream end, the combustion section comprising: a combustor assembly comprising: an inner liner and an outer liner each extended at least partially along a lengthwise direction and at an acute angle relative to the longitudinal centerline; a dome assembly extended between the inner liner and the outer liner , wherein the dome assembly , the inner liner , and the outer liner together define a combustion chamber therebetween; and a bulkhead assembly defining a plurality of walls coupled to the inner liner and generally surrounding the outer liner and dome assembly , wherein at least a portion of the bulkhead assembly is extended at least partially along a forward direction and defines a plenum between the bulkhead assembly and the dome assembly ; an outer casing surrounding the combustor assembly , wherein the outer casing is extended at least partially co-directional to the combustor assembly ; a fuel injector assembly extended through the outer casing , the bulkhead assembly , and the dome assembly ; and an inner casing , wherein the outer casing , the inner casing , and the combustor assembly together define a primary flowpath in direct fluid communication with the combustion chamber , and wherein the primary flowpath is extended at least along a forward direction and an aft direction defined by inner casing , the outer casing , and the combustor assembly , and wherein an oxidizer flows through the primary flowpath in serial flow through the plenum and the fuel injector assembly into the combustion chamber . an inner liner and an outer liner each extended at least partially along a lengthwise direction and at an acute angle relative to the longitudinal centerline; a dome assembly extended between the inner liner and the outer liner , wherein the dome assembly , the inner liner , and the outer liner together define a combustion chamber therebetween; and a bulkhead assembly defining a plurality of walls coupled to the inner liner and generally surrounding the outer liner and dome assembly , wherein at least a portion of the bulkhead assembly is extended at least partially along a forward direction and defines a plenum between the bulkhead assembly and the dome assembly ; an outer casing surrounding the combustor assembly , wherein the outer casing is extended at least partially co-directional to the combustor assembly ; a fuel injector assembly extended through the outer casing , the bulkhead assembly , and the dome assembly ; and an inner casing , wherein the outer casing , the inner casing , and the combustor assembly together define a primary flowpath in direct fluid communication with the combustion chamber , and wherein the primary flowpath is extended at least along a forward direction and an aft direction defined by inner casing , the outer casing , and the combustor assembly , and wherein an oxidizer flows through the primary flowpath in serial flow through the plenum and the fuel injector assembly into the combustion chamber . <EOS>