Acoustically tuned combustion for a gas turbine engine

A method of operating a turbine engine comprising:

• compressing a flow of air in a compressor section of the engine;
• directing a portion of the compressed air flow through an inlet into a fuel nozzle;
• injecting a flow of fuel through fuel jets into the compressed air flow passing through the fuel nozzle, wherein the fuel jets are formed at substantially the same axial position along the fuel nozzle;
• premixing the fuel flow and the compressed air flow in the fuel nozzle with a swirler positioned in the fuel nozzle that swirls at least the flow of compressed air passing through the fuel nozzle and with a mixing duct downstream of the swirler where the swirling air and fuel mix;
• passing the premixed fuel flow and compressed air flow out of the mixing duct and into a combustion chamber where the swirling air and fuel mixture is combusted, wherein the combustion process results in pressure waves that propagate upstream against the flow of swirling air and fuel mixture through the fuel nozzle and effect a time varying change in the flow rate of the compressed air flowing through the inlet and a time varying change in the flow rate of the fuel flowing through the fuel jets;
• and
• wherein the inlet and the fuel jets are positioned such that the time varying change in the flow rate of the compressed air flowing through the inlet and the time varying change in the flow rate of the fuel flowing through the fuel jets result in a substantially constant fuel/air ratio in the premixed fuel flow and air flow exiting the mixing duct.