Yang Qianmei, Li Shengji, Ye Linhui, Huang Xuefeng
College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
Department of Physics, Institute of Energy, Hangzhou Dianzi University, Hangzhou 310018, China.
Nanomaterials (Basel). 2022 Oct 1;12(19):3446. doi: 10.3390/nano12193446.
An Al/JP-10/oleic acid nanofluid fuel system has demonstrated potential in advanced combustion for aviation turbine engines. To improve the energy density of nanofluid fuel, a higher Al concentration requirement needs to be met. Correspondingly, a higher surfactant oleic acid concentration is required to maintain better dispersion stability. The increment of Al and oleic acid concentrations results in more frequent microexplosions, but a slower evaporation rate. Therefore, this paper proposes to deeply understand the contradiction of the concentration effect on the stability, physical properties, evaporation and microexplosion characteristics and obtain the best Al and oleic acid concentrations to maintain the most suitable comprehensive performance. Experiments on the stability, physical properties, evaporation and microexplosion characteristics were conducted, respectively. The analysis and discussion were then made to reveal the Al and oleic acid concentration effect on the stability, physical properties, evaporation and microexplosion characteristics. The results show that the optimum mass ratio of Al:oleic acid is 1:2 for the nanofluid fuels with Al concentrations of 2.5 wt.% or below, 1:2.5 for 5.0 wt.% or above to obtain the best stability. The physical properties of the nanofluid fuels such as density, surface tension and viscosity are linear, quartic and quadratic functions of Al concentration, respectively, relating to the internal flow and microexplosion of fuel droplets. With increasing oleic acid and Al concentration, the evaporation rates reduced, and the microexplosions became more frequent and intense. At a high ambient temperature of 600 °C, the evaporation rates were kept almost equivalent for JP-10, JP-10/oleic acid, and Al/JP-10/oleic acid fuels. It was found that the increment of ambient temperature can compensate for the reduction of the evaporation rate owing to the addition of oleic acid and Al nanoparticles, improving the evaporation and microexplosion performance.
一种铝/ JP - 10/油酸纳米流体燃料系统已在航空涡轮发动机的先进燃烧中展现出潜力。为提高纳米流体燃料的能量密度，需要满足更高的铝浓度要求。相应地，需要更高的表面活性剂油酸浓度来维持更好的分散稳定性。铝和油酸浓度的增加会导致更频繁的微爆炸，但蒸发速率会变慢。因此，本文旨在深入理解浓度对稳定性、物理性质、蒸发和微爆炸特性的影响矛盾，并获得最佳的铝和油酸浓度以维持最合适的综合性能。分别进行了关于稳定性、物理性质、蒸发和微爆炸特性的实验。然后进行分析和讨论，以揭示铝和油酸浓度对稳定性、物理性质、蒸发和微爆炸特性的影响。结果表明，对于铝浓度为2.5 wt.%及以下的纳米流体燃料，铝与油酸的最佳质量比为1:2；对于5.0 wt.%及以上的纳米流体燃料，最佳质量比为1:2.5，以获得最佳稳定性。纳米流体燃料的物理性质，如密度、表面张力和粘度，分别是铝浓度的线性、四次和二次函数，这与燃料液滴的内部流动和微爆炸有关。随着油酸和铝浓度的增加，蒸发速率降低，微爆炸变得更加频繁和剧烈。在600℃的高环境温度下，JP - 10、JP - 10/油酸和铝/ JP - 10/油酸燃料的蒸发速率几乎保持相等。研究发现，环境温度的升高可以弥补由于添加油酸和铝纳米颗粒而导致的蒸发速率降低，从而改善蒸发和微爆炸性能。
