Ducting arrangement with injector assemblies configured to form a shielding flow of air injected into a combustion stage in a gas turbine engine

A ducting arrangement comprising:

• a combustor wall in a combustion stage of a combustion turbine engine, the combustion stage fluidly coupled to receive a cross-flow of combustion products;
• an injector assembly disposed in the combustor wall, the injector assembly comprising a reactant-guiding structure comprising an inner wall and an outer wall, the reactant-guiding structure arranged to convey a flow of fuel/air mixture to admix with the cross-flow of combustion products, wherein the injector assembly includes a passageway defined between the inner wall and the outer wall, the passageway comprising an inlet side and an outlet side, the inner wall circumferentially wrapping around the outer wall at the inlet side, the passageway configured to inject a flow of air arranged for conditioning interaction of the flow of fuel/air mixture with the cross-flow of combustion products, the interaction conditioning based on a boundary formed by the flow of air that surrounds the flow of fuel/air mixture and is effective to provide an ignition delay to the flow of fuel/air mixture injected into the combustion stage.