镁基燃料水冲压发动机的热声振荡特性研究

发布时间：2018-04-11 07:31

本文选题：金属基燃料 + 热声振荡　；参考：《推进技术》2016年04期

【摘要】：为了探究金属基燃料发动机内的燃烧不稳定性问题,以镁基燃料水冲压发动机为背景,从理论上开展了热声振荡机理及特征频率特性的研究。通过Mg/H2O燃烧化学反应动力学分析,证实了高温环境中水的热分解特性是引起燃烧反应热释放波动的原因,结合不稳定燃烧中的声压振荡,合理解释了热声振荡的发生机理。进一步考虑平均流作用,建立了一维热声振荡计算模型,基于自行开发的热力计算程序,获得了三种选定镁基燃料一次燃烧产物的热力学性质及燃烧水燃比的上限2.0,2.4,2.6,同时结合边界条件、守恒条件求解了声压传播方程,获得了不同工况下的复频特性,实部均在700Hz以内属低频振荡,镁基燃料质量组分配比、进水口位置及水燃比均对特征频率虚部有较大影响,对于既定的燃烧室结构构型及镁基燃料,可通过调节进水量来主动干预热声振荡的发展趋势。
[Abstract]:In order to investigate the combustion instability in metal-based fuel engine, the thermoacoustic oscillation mechanism and characteristic frequency characteristics of magnesium based fuel water ramjet are studied theoretically.Through the kinetic analysis of Mg/H2O combustion chemical reaction, it is proved that the thermal decomposition of water in high temperature environment is the cause of the fluctuation of combustion reaction heat release, and the occurrence mechanism of thermoacoustic oscillation is explained reasonably by combining the acoustic pressure oscillation in unstable combustion.Considering the effect of average flow further, a one-dimensional thermoacoustic oscillation model is established, based on the self-developed thermodynamic calculation program.The thermodynamic properties of the primary combustion products of three selected Mg-based fuels and the upper limit of the water-fuel ratio of combustion are obtained. At the same time, the acoustic pressure propagation equation is solved by combining the boundary conditions and the conservation conditions, and the complex frequency characteristics under different operating conditions are obtained.All the real parts are low frequency oscillations within 700Hz. The distribution ratio of magnesium based fuel mass, the position of intake and the ratio of water to fuel have great influence on the imaginary part of characteristic frequency, and it has great influence on the structure configuration of combustion chamber and the magnesium based fuel.The development trend of thermoacoustic oscillation can be actively interfered by adjusting the influent amount.
【作者单位】：西安交通大学航天学院机械结构强度与振动国家重点实验室;
【基金】：国家自然科学基金(11102151) 高等学校博士学科点专项科研基金(20110201120022) 中央高校基本科研业务费专项资金
【分类号】：V231

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