Thermodynamic performance study of simplified precooled engine cycle with coupling power output

Horizontal takeoff and landing, reusable hypersonic vehicles have become one of hot spots of aviation field due to their high performance over all operating conditions. The propulsion system with high performance power output capability inside flight envelope is the key to conduct various missions. In order to meet the power demand of the vehicle systems, a coupled power output moderate pre-cooled cycle engine thermodynamic cycle based on closed-cycle supercritical helium was established. The sensitivity of propulsion system parameters and the overall performance of the design point of the thermodynamic cycle were analyzed. The influence law of the power extraction parameters was comparatively analyzed between the bleeding of high-pressure pre-combustion gas and expansion power from supercritical helium closed-cycle. According to the above results, a moderate precooled engine based on supercritical helium closed-cycle with power extraction was constructed. The results show that the scheme can achieve the performance of 109.6 kN thrust and 1,645 s specific impulse with 2 MW power extraction at 25.8 km, Ma5.0, which could provide a new idea for precooled engine scheme with power output.