组合循环推进系统燃料消耗模型及优化分析

Optimal analysis of the fuel consumption of combined cycle propulsion systems

根据飞行任务要求,准确计算出飞行器所需的燃料消耗是推进系统设计的前提。该文针对火箭基组合循环动力(RBCC)推进方式,并以"地面起飞—巡航—滑翔着陆"的高超音速飞行器为研究对象,采用理论分析的方法建立了燃料消耗的计算模型,并提出一种以最小燃料消耗为目标的多参数优化方法。周期跳跃式巡航飞行器燃料消耗的研究结果表明:随着巡航初速度、爬升段航迹倾角、巡航轨迹角的增加,燃料消耗量增加;随着飞行动压的增加,燃料消耗量先减小后阶跃式增加。优化分析结果表明:对于起飞质量100t、2h全球到达的RBCC组合动力高超音速飞行器,在升阻比为4时巡航跳跃周期数为46,最小燃料消耗量约为32t。研究结果表明该燃料消耗分析方法合理、可行,为高超音速飞行器及组合循环动力推进系统的工程设计提供了依据。

The propulsion system fuel consumption must be accurately predided for aircraft missions. A theoretical analysis of a hypersonic aircraft with a ＂boost cruise glide＂ flight mission profile powered by a rocket based combined cycle （RBCC） engine is used to predict the fuel consumption of the aircraft and to optimize the fuel consumption. The fuel consumption analysis of periodic hypersonic cruise trajectories shows that the fuel consumption decreases with. increasing initial cruise velocity, larger flight-path angles and larger flight path angles for cruising. As the flight dynamic pressure increases, the fuel consumption first decreases but then increases wilh a step change. The optimization results show that the hypersonic cruise stage should have 46 skip-periods with a minimum fuel consumption of about 32 tons for a two hour global reaching hypersonic aircraft with an initial weight of 100 tons and a lift-drag ratio of 4. The optimal results show that the fuel consumptionprediction model is reasonable. The present study can guide the design of combined cycle propulsion systems.