单相发汗冷却对脉冲爆震燃烧传播的影响

Effects of single-phase transpiration cooling on pulse detonation propagation

关键词:  脉冲爆震  发汗冷却  多孔介质  爆震传播  火焰传播速度

Key words:  Pulse detonation  Transpiration cooling  Porous media  Detonation propagation  Flame propagation velocity

摘要:

作为一种先进推进系统，脉冲爆震发动机热端部件的热载荷随着工作频率和飞行马赫数的提高而大幅增加。发汗冷却具有很高的冷却效率和更低的冷却剂消耗，使其成为脉冲爆震发动机燃烧室壁面冷却的理想方案。开展发汗冷却与爆震燃烧耦合研究，是爆震发动机发汗冷却设计的理论基础。为了探索发汗冷却的固体和流体结构对爆震燃烧的影响规律，本文采用实验方法，研究了不同多孔介质结构和单相发汗冷却对充分发展爆震燃烧传播过程的影响。结果表明，爆震波在多孔介质壁面上传播时发生减速，但不会引起爆震波解耦。单相发汗冷却引发爆震燃烧失效的主要原因是冷却剂的稀释作用使得局部当量比低于燃料的可爆极限。当冷却剂注入率超过12.5%时，爆震燃烧解耦。

Abstract:

As an advanced propulsion system， the thermal load on the hot end components of a pulse detonation engine significantly increases with the rise in operating frequency and Mach numbers. Transpiration cooling has greater cooling efficiency and less coolant consumption， making it a promising cooling solution for the pulse detonation engines combustion chamber wall. Research on the coupling relationship between transpiration cooling and detonation propagation forms the theory foundation of transpiration cooling design for the pulse detonation engines. In order to explore the effects of solid and fluid structures on detonation combustion in transpiration cooling， an investigation into the propagation characteristics of full development of detonation with different porous media structures and single-phase transpiration cooling was conducted via an experimental method. The results indicate that the detonation wave decelerates as it propagates along the porous media wall but does not lead to detonation failure. The primary reason for detonation failure induced by single-phase transpiration cooling is the dilution of the coolant， resulting in local equivalence ratios below the explosive limit of the fuel. When the coolant injection ratio exceeds 12.5%， detonation combustion becomes decoupled.