掺混空气对旋转爆震主燃烧室起爆性能对比试验

Comparative Experiments of Air Mixing on the Detonation Performance of the Rotating Detonation Main Combustion Chamber

为以工程化应用为基础研究旋转爆震燃烧室在涡轮发动机条件下旋转爆震波的传播特性,模拟某离心式涡喷发动机的工况,以常温煤油和496 K高温空气作为燃料和氧化剂,对基于外径为220 mm、环形宽度为40 mm的环形燃烧室和相同大小的含掺混结构的环形燃烧室开展对比试验。结果表明:在不同当量比工况下,观察到非稳定爆震模态、稳定双波旋转爆震模态和稳定3波旋转爆震模态。在封闭燃烧室中,当量比较低(低于0.8)或较高(高于1.1)时无法维持爆震波的稳定传播,呈现非稳定爆震模态;在当量比接近1时,呈现稳定双波旋转爆震模态。随着掺混结构的引入,燃烧室的工作范围得到拓宽(当量比为0.8~1.2),当当量比达到1.1时呈现稳定3波旋转爆震模态。在对应的工况范围内,掺混空气能显著提高旋转爆震波的传播稳定性。

In order to study the propagation characteristics of the detonation wave in the rotary detonation combustor under the condi⁃tion of turbine engines based on engineering applications,under simulated working conditions of a centrifugal turbojet engine by using nor⁃mal temperature kerosene and 496 K high-temperature air as fuel and oxidant,comparative experiments were conducted on a 220 mm out⁃er diameter annular combustor with a 40 mm flame tube height,and an annular combustor of the same size with mixing structure.The re⁃sults show that unstable detonation mode,stable two-wave rotating detonation mode,and stable three-wave rotating detonation mode are observed under different equivalent ratio conditions.For the closed combustion chamber,if the equivalence ratio is relatively low(below 0.8)or high(above 1.1),the detonation wave cannot be maintained,and unstable detonation mode occurs.If the equivalence ratio is close to 1,it exhibits a stable two-wave rotating detonation mode.With the introduction of the mixing structure,the working range of the combustion chamber is broadened(the equivalent ratio range is 0.8-1.2),and the stable three-wave rotating detonation mode appears at a higher equivalent ratio.In the range of working conditions corresponding to this study,mixing air can significantly improve the stable prop⁃agation of rotating detonation waves.