旋转爆震冲压发动机总体性能分析

Performance Analysis of Rotating Detonation Ramjet Engine

关键词:  旋转爆震发动机  冲压发动机  性能分析  推力  燃料比冲

Key words:  Rotating detonation engine  Ramjet engine  Performance analysis  Thrust  Fuel specific impulse

摘要:

为了快速可靠地评估旋转爆震冲压发动机的总体性能，针对冲压模态下的旋转爆震发动机建立了性能分析模型。模型以飞行条件和冲压发动机关键几何参数作为输入参数，结合气体动力学和CJ爆震理论，获得旋转爆震燃烧室的流场参数分布以及发动机喷管排气参数，输出发动机推力以及燃料比冲，建立了基于连续旋转爆震的冲压发动机性能评估方法。模型参与反应的燃料和氧化剂分别为煤油以及空气，主要研究了燃料温度、喷管喉部面积、燃烧室环面面积、反应物当量比、飞行马赫数以及飞行高度对发动机燃料比冲、推力的影响趋势。研究结果表明，控制其它变量不变，发动机推力与燃料比冲随燃料温度上升而提高；随喷管喉部面积、燃烧室环面面积减小而增大；随飞行高度增加而降低；燃料比冲随当量比、马赫数增大而减小，而推力随当量比、马赫数增大而增大。在高度为25km，马赫数为4，当量比为0.6的工况下，发动机燃料比冲可达到1740s。分析结果表明，模型计算方法可靠，可快速计算出旋转爆震冲压发动机的推力性能。

Abstract:

In order to quickly and reliably predict the performance of a rotating detonation ramjet engine， a computational model of performance analysis was established. With the flight conditions and the key geometric parameters of the engine as inputs， distributions of the flow field parameters in rotating detonation combustion chamber and the exhaust parameters were obtained， combined with the gas dynamics and CJ detonation theory. The outputs are thrust and fuel specific impulse. The performance evaluation method of a continuous rotating detonation ramjet engine was established. The reactants are kerosene and air. The model mainly studies the relationship of fuel temperature， nozzle throat area， combustion chamber area， equivalence ratio， flight Mach number and flight height， with the fuel specific impulse and thrust of the engine. The results show that， controlling other variables unchanged， thrust and fuel specific impulse of the engine increase with the rise of the fuel temperature， and increase with the decrease of the nozzle throat area and combustion chamber area. In addition， thrust and fuel specific impulse decrease with the increase of the flight height. The fuel specific impulse decreases with the increase of equivalence ratio and Mach number， and the thrust increases with the increase of equivalence ratio and Mach number. The fuel specific impulse of the engine can reach 1740s at the Mach number of 4， an equivalent ratio of 0.6 and a height of 25km. The model can quickly and reliably calculate the propulsion performance of the engine.