• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Combustion and Flame >Microexplosions and ignition dynamics in engineered aluminum/polymer fuel particles
【24h】

Microexplosions and ignition dynamics in engineered aluminum/polymer fuel particles

机译：工程铝/聚合物燃料颗粒的微爆炸和点火动力学

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Aluminum particles are widely used as a metal fuel in solid propellants. However, poor combustion efficiencies and two-phase flow losses result due in part to particle agglomeration. Recently, engineered composite particles of aluminum (Al) with inclusions of polytetrafluoroethylene (PTFE) or low-density polyethylene (LDPE) have been shown to improve ignition and yield smaller agglomerates in solid propellants. Reductions in agglomeration were attributed to internal pressurization and fragmentation (microexplosions) of the composite particles at the propellant surface. Here, we explore the mechanisms responsible for microexplosions in order to better understand the combustion characteristics of composite fuel particles. Single composite particles of Al/PTFE and AI/LDPE with diameters between 100 and 1200 pm are ignited on a substrate to mimic a burning propellant surface in a controlled environment using a CO2 laser in the irradiance range of 78-7700 W/cm(2). The effects of particle size, milling time, and inclusion content on the resulting ignition delay, product particle size distributions, and microexplosion tendencies are reported. For example particles with higher PTFE content (30 wt%) had laser flux ignition thresholds as low as 77 W/cm(2), exhibiting more burning particle dispersion due to microexplosions compared to the other materials considered. Composite AI/LDPE particles exhibit relatively high ignition thresholds compared to Al/PTFE particles, and microexplosions were observed only with laser fluxes above 5500 W/cm(2) due to low LDPE reactivity with Al resulting in negligible particle self-heating. However, results show that microexplosions can occur for Al containing both low and high reactivity inclusions (LDPE and PTFE, respectively) and that polymer inclusions can be used to tailor the ignition threshold. This class of modified metal particles shows significant promise for application in many different energetic materials that use metal fuels. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
机译：铝颗粒被广泛用作固体推进剂中的金属燃料。然而，部分由于颗粒团聚而导致不良的燃烧效率和两相流损失。近来，已显示工程化的铝（Al）复合颗粒与聚四氟乙烯（PTFE）或低密度聚乙烯（LDPE）夹杂物可改善引燃性并在固体推进剂中产生较小的附聚物。团聚的减少归因于推进剂表面复合颗粒的内部加压和破碎（微爆炸）。在这里，我们探索引起微爆炸的机理，以便更好地理解复合燃料颗粒的燃烧特性。直径在100到1200 pm之间的Al / PTFE和AI / LDPE的单个复合颗粒在基板上被点燃，以在受控环境中使用CO2激光在78-7700 W / cm（2）的辐照范围内模拟燃烧的推进剂表面（2 ）。报告了粒径，研磨时间和夹杂物含量对产生的点火延迟，产品粒径分布和微爆炸倾向的影响。例如，具有较高PTFE含量（30 wt％）的颗粒具有低至77 W / cm（2）的激光通量点火阈值，与其他考虑的材料相比，由于微爆而显示出更多的燃烧颗粒分散。与Al / PTFE颗粒相比，复合AI / LDPE颗粒显示出相对较高的着火阈值，并且由于LDPE与Al的反应性低，仅在5500 W / cm（2）以上的激光通量下才观察到微爆炸，导致颗粒自热可忽略。但是，结果表明，含有低和高反应性夹杂物（分别为LDPE和PTFE）的Al可能发生微爆炸，并且聚合物夹杂物可用于调整起火阈值。这类改性金属颗粒显示出可望在许多使用金属燃料的高能材料中应用的巨大希望。 （C）2016年燃烧研究所。由Elsevier Inc.出版。保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号