空天机复合循环推进技术新概念研究——液化空气循环在其中的应用

CONCEPTUAL STUDY ON A COMBINED CYCLE OF PROPULSION FOR AEROSPACE PLANE——APPLICATION OF LACE

关键词:  混合式发动机  液体空气  分离  液氧  液氮

Key words:  Combined engine  Liquid air Separation  Liquid oxygen  Liquid nitrogen

摘要:

研究了空天机复合循环推进技术中的一个新概念——以液化空气循环为基础的SERJ组合发动机性能。计算了空气液化后分离为液氧和液氮后组合发动机在不同高度、不同飞行马赫数下的性能曲线,并考虑了液化空气量对组合发动机性能的影响。对计算结果的分析表明,液化空气循环虽然使组合发动机推力下降,但能使比冲有较大幅度的上升;液化空气量过大与过小均不利于进一步提高比冲性能,而是存在一个最佳值。

Abstract:

This paper investigates a new concept of combined cycle propulsion system for aerospace aircraft, i.e.the performance of SERJ combined cycle engine based LACE(liquid air cycle engine).The perfomance of the engine with liquefied nitrogen and oxygen separated from liquefied air at different flight altitude and Mach numbers is calculated, the conclusions can be obtained as follows.1) The application of LACE will significantly improve the specific impulse performance despite the occurence of thrust decrease.2) It can be seen from the computational results that there exists an optimal engine performance at certain flow rate of liquefied air.