Performance evaluation and optimization for a novel supersonic precooled engine based on hydrogen production technology from ammonia cracking

Abstract

Precooling technology is a widely used method for increasing the flight speed of turbojet engines. To solve the problems of oversized fuel tank and engine performance degradation caused by the low density of hydrogen fuel, a new precooled engine cycle based on hydrogen production technology from ammonia cracking is proposed. To evaluate the engine performances, a thermodynamic model and a test platform are established. The study shows that the test heat sink of ammonia is 4.12 MJ at 620.5 °C, and the upper boundaries of heat sink and hydrogen production rate of ammonia are higher than other chemical fuels. Besides, the optimized fuel ratio is set to 2.0, and the best compressor pressure ratio could be obtained at the point with the highest engine performances Further, the maximum flight Mach number of precooled engine is Ma4.69, and compared with GE90 and J-58 engines, the carbon emission of precooled engine could be reduced by 94.15% and 72.95% respectively. Moreover, by increasing the cold storage degree, the engine performance can be further improved especially at high pressure ratio. Overall, the research of this paper is hopeful to provide a new idea and necessary theoretical support for the development of high-performance supersonic aero-engine.