回流型脉冲爆震燃烧室结构动态响应实验研究

Experimental investigation on dynamic response of reverse flow pulse detonation combustor

脉冲爆震燃烧室是脉冲爆震发动机的核心部件,工作过程中承受高温以及周期性高速移动的瞬态高压载荷,爆震室的强度和安全性是其工程应用的前提。本文针对一种新型的回流型爆震室,建立了台架工作环境的爆震室压力、温度、动态应变试验测试平台,初步开展了5 Hz工况下的气/热载荷与结构动态响应测试与分析。结果表明:爆震室空间内包含完整起爆过程以及压力反传,压力时空变化比爆震波理想传播模型更加复杂;爆震室结构表现出受高速冲击爆震压力载荷引起的瞬态响应的同时,压力在回流型结构内传播产生弯矩,将引起爆震室结构的低频弯曲振动;爆震室的低频响应包含50 Hz,173 Hz和224 Hz等频率成分,幅值分散性小,而高频成分主要分布在10~30 kHz,幅值分散性较大。

Pulse detonation combustor is the core component of pulse detonation engine(PDE).Under high temperature and periodic high-speed moving transient high-pressure load,the strength and safety of the PDE combustor is the premise of its engineering application.In this paper,a rig test platform of a novel reverse flow PDE combustor was established for pressure,temperature,and dynamic strain measurement.Preliminary test at 5 Hz were carried out and aerodynamic/thermal load and structural dynamic response were measured and analysed.The results indicate that the detonation combustor space contained a complete initiation process and pressure back propagation,of which the spatiotemporal pressure variation was more complex than the ideal model of detonation waves propagation.The PDE combustor exhibited the transient response caused by high-speed im⁃pact of detonation pressure load,while bending moments induced by pressure propagated within the reverse struc⁃ture,generating low-frequency bending vibration of the combustor structure.The low-frequency components of the detonation chamber contain 50 Hz,173 Hz and 224 Hz with the amplitude dispersion is small,while the high-frequency components are mainly distributed in 10~30 kHz with the amplitude dispersion is large.