Improving the ignition and combustion of JP10/boron-based nanofluid fuel droplets by the interaction of PTFE and boron

With a high demand for high-performance spacecraft, the development of new nanofluid fuels has become a major opportunity and challenge. As solid-liquid hybrid fuels, the combustion of nanofluid fuels is affected by various factors and the combustion performance needs to be improved. In this paper, the JP10/boron (B)-based nanofluid fuel droplets containing polytetrafluoroethylene (PTFE) with 10 mass% nB/PTFE content were prepared by a mechanical mixing method, and their combustion characteristics were investigated, especially the droplet behavior and flame characteristics. Additionally, the effects of nano-sized boron (nB) and nano-sized polytetrafluoroethylene (nPTFE) on the oxygen consumption and reaction characteristics of droplets at different combustion stages were also analyzed. The combustion process of the JP10/B-based nanofluid fuel droplets with nPTFE addition is mainly defined as four stages, namely ignition stage, mixed combustion stage, secondary combustion stage, and boron burning stage. The addition of a small amount of nPTFE to the JP10/B-based nanofluid fuel does not reduce the ignition delay time of the droplet, but the combustible gas products such as CO and CF4 generated by the reaction between nB and nPTFE in the mixed combustion stage can destroy the droplet strongly and enhance the combustion of JP10, so the combustion time of the JP10/B-based nanofluid fuel droplets with nPTFE addition in this stage is shortened by 10.1% compared with that of the JP10/B-based nanofluid fuel droplets. In addition, nPTFE destroys the boron surface oxide layer and improves the combustion efficiency of boron particles, and the maximum burning intensity of droplets can be increased by 47%. The particle size of condensate combustion products is reduced by 85% because the gases generated split the agglomerates into small fragments.