旋转爆震发动机液态燃料预爆器设计及爆震燃烧特性研究

Investigation on Design and Detonation Combustion Characteristics of Liquid-Fuel Initiator for Rotating Detonation Engine

关键词:  旋转爆震发动机  预爆器  爆震燃烧特性

Key words:  Rotating detonation engine  Initiator  Detonation combustion characteristics

摘要:

为了解决液态燃料旋转爆震发动机点火起爆困难和结构紧凑等问题，进行了以液态航空煤油为燃料的预爆器设计，包括离心/预膜复合燃油雾化喷嘴、点火/传焰凹腔、三枝管预爆室等结构。以液态航空煤油/氧气为工作介质，进行了离心/预膜复合燃油雾化喷嘴雾化特性和预爆器爆震燃烧特性试验研究，获得了离心/预膜复合燃油雾化喷嘴雾化粒径变化规律，以及预爆器内爆震波压力、传播速度等变化规律。研究表明：离心/预膜复合燃油雾化喷嘴的雾化效果随气流流量和油压增加而改善，预爆器接近出口位置（PCB5处）爆震波峰值压力可超过3.80MPa，爆震波传播速度可达1800m/s；随着当量比增加，预爆器内过驱爆震位置提前，有利于缩短预爆器的长度。

Abstract:

To solve difficulties of ignition and compact structure in liquid-fuel rotating detonation engine, an initiator with liquid aviation kerosene as fuel was designed. It includes centrifugal/pre-film composite fuel atomizing injector, ignition/transmission flame concave cavity and three-branches pipe initiator chamber. The atomization characteristic of the centrifugal/pre-film composite fuel atomizing injector and detonation combustion characteristic of the initiator were experimentally studied with liquid aviation kerosene and pure oxygen. The change rules of atomized particle sizes behind the centrifugal/pre-film composite fuel atomizing injector were obtained. The detonation combustion characteristics such as pressure and flame propagation speed in the initiator were gained. The results show that, the atomization effect improves with increases in fuel pressures and airflow rate. Near the exit of the initiator (location of PCB5), the peak pressure of the detonation waves exceeds 3.80MPa and the maximum velocity reaches 1800m/s. With the increase of equivalence ratio, the positions of the overdriven detonation waves in the initiator are advanced, which are beneficial to shorten the length of the initiator. The research results provide ideas for the design of the initiator using liquid fuel.