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要掌握凝胶推进剂在燃烧室内燃烧特性,必须首先认识清楚单个凝胶推进剂液滴的燃烧机理。为了揭示凝胶燃料液滴特殊的燃烧机制,在考虑相分离阶段液滴内部温度和浓度梯度变化的基础上,完善并发展了一种新的数学模型来描述凝胶燃料液滴的相分离过程,并且用之研究了凝胶燃料单液滴蒸发/燃烧过程中的相分离特性。研究结果表明:相分离阶段,液滴的半径按d2定律收缩,与实验结果吻合;液滴点火后,火焰由初始位置向液滴外围扩展,火焰温度不断上升,并且逐渐趋于稳定;相分离前期,在液滴内部,特别是表面附近的区域,质量的输运较热量输运容易,而相分离后期则呈现相反趋势,这就导致在相应的区域相分离前期比后期有更大的温度梯度,而相分离后期比前期有更大燃料浓度梯度。
To understand the combustion characteristics of a gel propellant in a combustion chamber, one must first understand the combustion mechanism of individual gel propellant droplets. In order to reveal the special combustion mechanism of gel fuel droplets, a new mathematic model was developed to describe the phase separation process of gel fuel droplets, based on the change of temperature and concentration gradient of droplet in phase separation phase , And used to study the phase separation characteristics of gel fuel single drop evaporation / combustion process. The results show that the radius of the droplets shrinks according to the d2 law during phase separation, which agrees well with the experimental results. After the droplets are ignited, the flame expands from the initial position to the periphery of the droplet and the temperature of the flame rises gradually and gradually becomes stable. In the early stage, the transport of mass within the droplet, especially in the vicinity of the surface, is easier than the transport of heat and the opposite phase in the late phase, leading to a greater temperature in the corresponding region than in the latter part of the phase separation Gradient, while phase separation later than the previous fuel concentration gradient.