自燃推进剂液流自适应高频脉冲爆轰波形成机理研究

The detonation of hypergolic propellants is a new topic in the field of detonation propulsion, and how to form a reliable and effective pulse detonation wave with hypergolic propellants is an important problem. This project focused on the study of the pulse detonation wave formation mechanism with MMH/NTO propellants. To reveal the influences of propellant droplet size and its distribution, the structure and size of detonation combustion chambers and other factors on the detonation wave formation processes of hypergolic propellants, the simplified model for the reaction kinetic mechanism of detonation with MMH/NTO propellants was constructed, and the deflagration to detonation transition processes of hypergolic propellants were investigated by combining with the high pressure evaporation theory and the CFD simulation technology under the cold environment. To discover the coupling mechanism of the hypergolic propellants pulse detonation waves between the cold and hot environments, the detonation wave formation processes of hypergolic propellants under the hot environment were studied numerically with the boundary conditions, which acquired from the transient measurements of propellants atomization parameters under the disturbances of the simulated detonation waves by using TR-PIV and TR-PDS methods. To show the flame propagation and the complex wave structures during the formation processes of the pulse detonation waves with hypergolic propellants, the experimental studies on the pulse detonation processes of hypergolic propellants were accomplished by using the high-speed camera and schlieren technique. The research results will not only enrich the detonation mechanism connotation of the hypergolic propellants, but also will promote the development of the new power technology, which is represented by the pulse detonation engine.

自燃推进剂的爆轰是爆轰推进领域的新课题，而如何可靠形成有效的自燃推进剂脉冲爆轰波是其中的重要难题。本项目专注于研究MMH/NTO自燃推进剂脉冲爆轰波形成机理。通过构建MMH/NTO自燃推进剂爆轰反应动力学简化机理模型，结合高压蒸发理论与CFD仿真技术，研究冷环境下自燃推进剂燃烧转爆轰过程，揭示推进剂液滴粒径及其分布、爆轰燃烧室结构尺寸等因素对自燃推进剂爆轰波形成过程的影响规律；利用TR-PIV与TR-PDS方法获得模拟爆轰波扰动效应下推进剂喷注雾化的瞬态参数，并将其作为数值计算边界条件，研究热环境下自燃推进剂爆轰波的形成过程，揭示冷、热环境下自燃推进剂脉冲爆轰波的耦合机制；利用高速照相与纹影技术，实验研究自燃推进剂脉冲爆轰过程，揭示自燃推进剂脉冲爆轰波形成过程中的火焰传播过程与复杂波系结构。研究结果不仅将丰富自燃推进剂爆轰机理的内涵，同时还将促进以脉冲爆轰发动机为代表的新型动力技术发展。

对自燃推进剂爆轰过程的研究，是认识自燃推进剂爆轰特性，支撑自燃推进剂爆轰发动机工程应用研究的重要方面。本项目以自燃推进剂爆轰问题为主线，开展了MMH/NTO自燃推进剂反应机理、爆轰流场仿真与爆轰实验研究。完成了自燃推进剂详细反应机理及其简化、总包反应机理研究，构建了13组分7反应的MMH-NTO总包反应机理。在爆轰波形成过程的典型压力与温度范围内（温度270K-900K、压力0.1MPa-5MPa、氧燃比1.4-2.6），该总包机理的计算精度与详细机理计算的着火延迟时间和绝热火焰温度的误差不超过2%。该总包机理可用于自燃推进剂反应流的大规模工程计算。建立了环形爆轰燃烧室下自燃推进剂爆轰的理论模型，数值实现了自燃推进剂爆轰波周期性传播过程，分析了周期性爆轰波传播模态。通过压力云图、反应锋面等计算结果分析，揭示了混合比影响爆轰波传播模态转变的作用机理。该结果有助于深入认识自燃推进剂爆轰波的周期性传播过程，能够为工程设计提供定性设计依据。完成了模拟爆轰波对推进剂喷注雾化过程影响的试验，证实了模拟爆轰波周期性作用对推进剂喷雾分布的周期性影响。完成了MMH/NTO自燃推进剂爆轰过程的试验研究，利用高速摄影技术成功获得了周期性旋转爆轰波传播过程的火焰图像，直观的呈现了自燃推进剂从缓燃到爆轰波形成的演变过程。通过对宽范围流量与混合比条件下的MMH/NTO自燃推进剂爆轰实验，累积了自燃推进剂爆轰的大量试验数据。基于数据分析，获得了自燃推进剂爆轰波周期性稳定传播的临界条件。通过对自燃推进剂爆轰的特征速度分析，试验证实了自燃推进剂爆轰的特征速度相比缓燃燃烧提高了4%~10%。这些试验数据和分析结果，对爆轰发动机的工程应用研究具有重要的参考意义。