前置涡轮组合脉冲爆震发动机性能分析

Performance Analysis of Pre-Turbine Hybrid Pulse Detonation Engine

为解决纯脉冲爆震发动机地面启动问题,并提升其低马赫数下的性能优势,提出了一种利用外涵中爆震室头部压力驱动内涵中涡轮转动部件的前置涡轮组合脉冲爆震发动机,建立了相应的性能分析方法,并对其部件特性及整机性能进行了计算研究。结果表明,近似稳态的涡轮总温总压进口条件可以在该组合发动机中实现,同时随着爆震室头部侧向开孔面积与爆震室面积之比(即驱动面积比)增大,流入发动机内涵驱动涡轮的气体流量增大,而涡轮前总温、总压及涡轮落压比减小,组合发动机整机推进性能增大;通过改变驱动面积比的大小,可以获得不同的压气机增压比以适于不同的飞行马赫数,进而实现发动机宽广的工作范围。

The pressure ahead of detonation chamber in bypass is utilized to drive a fore turbine combined with pulsed detonation engine. A performance model is established to study the components characteristics and propulsive performance of the engine. The calculation results show that a quasi-stable inlet condition of total temperature and total pressure can be realized in this combined PDE. The increase in the area ratio of side hole to detonation tube section （drive area ratio） leads to the increase in flow flux inpouring the turbine. But the total turbine inlet temperature,total turbine inlet pressure and blow - down ratio of turbine decrease as increasing drive area ratio. Contrast with conventional engine based on constant - pressure combustion, the turbine inlet temperature of combined PDE with drive area ratio 1 is 80K lower than the former under the same pressure ratio and fuel-gas ratio. In another words, increase in drive area ratio may improve the performance of combined PDE. Pressure ratio can be changed by changing in drive area ratio to adapt varied flight Mach number, which induces the enlargement of operating range.