Patent attributes
A turbofan engine includes a fan, a core turbine engine having one or more turbines and an exhaust section, and a hydrogen-exhaust gas heat exchanger in flow communication with the exhaust section and hydrogen flowing along a hydrogen supply line. The hydrogen-exhaust gas heat exchanger defines a load capacity factor determined by raising a product to a one-quarter power, the product being determined by multiplying a heat transfer surface area density associated with the hydrogen-exhaust gas heat exchanger by a process conductance parameter that relates characteristics of hydrogen, ambient air, and exhaust gas at takeoff, as well as a fan diameter of the fan and a number of turbine stages of the turbofan engine. The load capacity factor is between 4.37 and 28.65 for the fan diameter being between 0.5 and 3.5 meters and the heat transfer surface area density being between 500 m
