整装式含能液体多点点火气液相互作用特性研究

The combustion for the bulk-loaded energetic liquid is a process using the instability of the fluid resulting in gas-liquid turbulent mixing up to sufficient burning, involving multiphase flow, turbulent combustion and transient combustion stability. Its breakthrough point lies in understanding and grasping the gas-liquid turbulent phenomenon and mechanism in the combustion process of energetic liquid. Based on this as engineering background, this project present a new conception that from the view of coupling-matching associations among the multi-point ignition and the boundary shape of the combustion chamber, the control method and mechanism research of combustion stability of the bulk-loaded energetic liquid will be carried out. The methodology of combining the experiment and numerical simulation is employed to study this project. The expansion processes and turbulent mixing characteristic of gas-liquid of the multi-strand combustion-gas jets formed by multipoint ignition in bulk-loaded liquid will be studied by experiments. Then, the unsteady multiphase flow model with three-dimension is established to analyze the pressure wave, temperature wave, and the spatial-temporal evolution characteristic of the interference and coalescence of the multi-strand Taylor cavities in the flow field. Based on this, the multiphase reaction mode with three-dimension on the combustion and propelling of bulk-loaded energetic liquid is established. The coupling relationship of multipoint ignition parameter, the structure parameters with combustion performance is discovered theoretically to seek the new method of restraining the positive feedback mechanism of Taylor-Helmholtz instability effect in the flow field. The research results can establish the theoretical foundation for the combustion stability for the bulk-loaded energetic liquid.

整装式含能液体的燃烧是一种利用流体不稳定性造成气液湍流掺混直至充分燃烧的过程，它涉及多相流、瞬态燃烧稳定性控制等问题，其关键突破点在于对整装式液体燃烧过程中气液湍流掺混现象及其机理的认识和把握。本项目以此为工程背景，提出一个新构思，即从多点点火与燃烧室边界形状耦合匹配的角度出发，深入开展整装式含能液体燃烧稳定性的控制方法和机理研究。拟采用试验和数值模拟相结合方法，开展基于多点点火形成的多股燃气射流在整装式液体中扩展及气液湍流掺混特性的实验研究；建立三维非稳态多相流模型，分析流场内复杂的压力、温度波及多股Taylor空腔相互干涉、聚并的演化特性；在此基础上，建立整装式含能液体燃烧推进的多相反应模型，从理论上揭示多点点火参数、燃烧室结构参数与燃烧性能的耦合关系，寻求抑制燃烧场内Taylor-Helmholtz不稳定效应正反馈机制的新方法，研究成果可为整装式含能液体燃烧稳定性的控制奠定理论基础。

整装式含能液体的燃烧是一种利用流体不稳定性造成气液湍流掺混至充分燃烧的过程，它涉及多相流、瞬态燃烧稳定性控制等问题，其关键突破点在于对整装式液体燃烧过程中气液湍流掺混现象及其机理的认识和把握。本项目以此为工程背景提出一个新构思，即从多点点火与燃烧室边界形状耦合匹配的角度出发，将流动不稳定性和燃烧不稳定性剥离，深入开展整装式含能液体燃烧稳定性的控制方法和机理研究。采用试验和数值模拟相结合方法，首先搭建多股燃气射流在液体工质中扩展的实验模拟平台，设计多结构观察室和喷孔结构，采用数字高速录像系统观测多股燃气射流在多结构观察室及喷孔下的扩展特性，同时实验了不同喷孔间距、喷射压力、喷孔直径对扩展过程的影响。结果表明渐扩比较大的圆柱渐扩型观察室中射流扩展更稳定，适当增加喷孔间距可增强射流径向扩展，增大喷孔直径和喷孔间距都会增大射流强度，轴向位移增大。在此基础上，对燃气射流扩展过程提出假设，以简化其数学物理模型，同时结合射流扩展特性选取适合的湍流模型，建立多股燃气射流与液体工质相互作用的三维非稳态气液湍流数理模型，并对典型工况模型进行网格无关性验证，以提高计算效率，通过计算分析了流场内复杂的压力、温度波及多股Taylor空腔相互干涉、聚并的演化特性，揭示出导致流动不稳定性的诱因。最终结合冷态射流的结果，形成整装式含能液体燃烧推进的多相反应模型，从理论上揭示出点火参数、燃烧室结构参数与燃烧性能的耦合关系，及燃烧场内传热、传质、化学反应特性，得到抑制燃烧场内Taylor-Helmholtz不稳定效应正反馈机制的新方法，研究成果可为整装式含能液体燃烧稳定性的控制奠定理论基础。