Abstract: For a better understanding of the performance of heat exchange pre-cooling engine, a heat exchanger in which the tubes were mounted by staggered arrangement is designed firstly. Then, the pre-cooling characteristics of the heat exchanger are simulated numerically. Finally, the performance of the heat exchanger enhanced engine is analyzed theoretically. The simulation results confirm a favorable characteristics of the heat exchanger. On the condition that the mass flow ratio of hydrogen and air is 0.03-0.09 and the flight Mach number is 2.5-4.0, the total temperature of the incoming air can be cooled by 90.6-471.2 K through the heat exchange pre-cooler, the temperature of low-temperature hydrogen arises by 266.1-455.3 K. Analyses show that the heat exchange pre-cooling technology expands the flight envelope to Ma 4.0 for the conventional turbine engine, reaching the connecting speed range of scramjet. Compared with the conventional turbine engine, the thrust with afterburning can be recovered to as high as the thrust of designed point as the mass flow ratio of hydrogen and air is 0.03. While the mass flow ratio of hydrogen and air rises to 0.09, the thrust with afterburning can be improved to approximately two times the thrust of the designed point. Furthermore, the specific impulse and specific fuel consumption (only including the hydrogen for combustion) can be promoted slightly when the flight velocity is slower than Ma 2.6, whereas when the flight velocity exceeds Ma 2.6, pre-cooling will not effectively restrain the rapid deterioration of specific impulse and specific fuel consumption any more.

Key words: heat exchange pre-cooler, pre-cooling characteristics, pre-cooling engine, engine performance, Turbine Based Combined Cycle (TBCC)