斜爆轰波系在受限空间内的演变及其临界条件的数值研究

Numerical Study on Structural Evolution and Transitional Criteria of Oblique Detonation Waves in Confined Space

关键词:  斜爆轰发动机  波系结构  临界条件  受限空间  激波反射

Key words:  Oblique detonation engine  Wave structure  Critical condition  Confined space  Shock reflection

摘要:

针对斜爆轰发动机简化模型，采用多组分基元化学反应流动数值模拟技术，数值分析了斜爆轰波系在受限空间内的宏观结构特征及其演变，并进一步分析了爆轰波系结构转变的临界条件。研究结果发现，随着楔面角度的增加，依次出现四种结构：激波诱导燃烧、斜爆轰波双规则反射、回流区马赫反射、楔面燃烧。对于稳定的波系结构，楔面压缩角同时存在下临界、亚临界以及超临界三种极限条件，在波系演变过程还伴随激波规则反射和马赫反射的转变。

Abstract:

Numerical techniques for multi-species chemical reacting flows are applied to study the macrostructures of oblique detonation waves in confined space. The key features， the evolution of the overall wave structure， and the transitional criteria are analysed. The results show that with the increase of wedge angle， four structures appear in turn： shock-induced combustion， oblique detonation double regular reflection， Mach reflection in reflux zone， and wedge combustion. The simulations reveal three critical conditions of the compression angle for the maintenance of stable wave structures， i.e.， lower-critical， sub-critical， and upper critical conditions. In addition， the transition between regular and Mach reflections occurs during the evolution process of the macro wave structure.