US Patent 11834995 Air-to-air heat exchanger potential in gas turbine engines

An air-to-air heat exchanger in flow communication with a gas turbine engine is provided. The air-to-air heat exchanger has an air-to-air heat exchanger potential defined by a product raised to a half power, the product being a heat transfer surface area density associated with the air-to-air heat exchanger multiplied by an airflow conductance factor associated with the gas turbine engine. The air-to-air heat exchanger potential is between about 6.7 and 19.5 for a bypass ratio associated with the gas turbine engine between about 3 and 10 and the heat transfer surface area density being between about 3,000 m