级间旋转爆震涡轴发动机热力过程及性能分析

Thermodynamic Process and Performance Analysis of Inter-Stage Turbine Rotating Detonation Turboshaft Engine

关键词:  涡轴发动机  级间旋转爆震  集总参数模型  性能分析  总体设计

Key words:  Turboshaft engine  Inter-Stage turbine rotating detonation  Lumped parameter model  Performance analysis  Overall design

摘要:

针对一种级间旋转爆震涡轴发动机概念建立了集总参数模型，研究了发动机内部温度、压力、流量分配及涡轮效率等参数随爆震燃烧特性的变化规律。研究结果表明：级间旋转爆震燃烧室的引入可实现对燃气的二次增温增压，能够较为明显地提升涡轴发动机单位功率，但同时也将改变发动机主流与冷却气流的流量分配比例，使得涡轮流量系数和级载荷系数变化、涡轮效率下降；T700涡轴发动机在引入级间旋转爆震燃烧室后，最优爆震燃烧温升为560K，单位功率增加36.9%，耗油率上升14.6%。相比于高热力循环参数发动机（压气机压比π_C=21，主燃烧室出口总温T₄^*=1900K），中、低热力循环参数发动机（π_C=13～17，T₄^*=1500～1700K）引入级间旋转爆震燃烧室后的性能提升更为明显。开展起飞阶段采用爆震大功率模式、巡航阶段采用常规发动机模式的级间旋转爆震变循环涡轴发动机研究，可在高热力循环参数的发展路线之外，为未来先进涡轴发动机的发展提供有益的技术支撑。

Abstract:

A lumped parameter model was established for the turboshaft engine based on the concept of inter-stage turbine rotating detonation. With different detonation combustion characteristics， change rules of engine parameters are investigated such as the internal temperature， pressure， the mass flow allocation and the turbine efficiency. The results indicate that introducing a rotating detonation combustor between turbine stages could reheat and recompress the gas， and then increase the specific power of the turboshaft engine significantly. Simultaneously， it will also change the distribution ratio between the engine mainstream flow and cooling flow， which influences the flow coefficient and the stage loading factor of turbine and decreases the turbine efficiency. For the T700 turboshaft engine assisted by the inter-stage turbine rotating detonation combustor， the optimal detonation temperature rise is 560K， the specific power of the engine increases by 36.9%， and the specific fuel consumption increases by 14.6%. Compared with the engine with high thermal-cycle parameters （compressor pressure ratio π_C=21， outlet total temperature of main combustion T₄^*=1900K）， the performance improvement of the engine with medium/low thermal-cycle parameters（π_C=13～17， T₄^*=1500～1700K）is more obvious after introducing the inter-stage turbine rotating detonation combustor. Different from the development route of high thermal-cycle parameters， the research of variable-cycle turboshaft engine that operates in the high-power detonation mode during the take-off phase and in the conventional engine mode during cruise will provide a useful technical support for the turboshaft engines development in the future.