Effect of binder melt flow on the leading edge flames of solid propellant sandwiches
Effect of binder melt flow on the leading edge flames of solid propellant sandwiches
复制标题
粘合剂熔体流动对固体推进剂夹层材料前缘火焰的影响
DOI：
10.1016/j.proci.2018.06.071
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发表时间：
2019
影响因子：
3.4
通讯作者：
S. Chakravarthy
中科院分区：
文献类型：
--
作者：
K. Gnanaprakash;S. Chakravarthy
本研究报告了粘结剂熔体流动对不同类型的夹层推进剂（即纯粘结剂、微铝粘结剂和纳米铝粘结剂）燃烧行为的影响，特别是燃烧速度控制位点，即前缘火焰（LEFs）。通过高时空分辨率下捕获的燃烧图像，测量了固定在三明治层状界面边缘上的lef之间的距离。同样，粘结剂熔体流动的程度也从三明治的淬火表面测量。在2、4、7 MPa压力下，对不同中层厚度和中层含量的夹层材料进行了燃烧速率实验。考虑了两种不同的固化剂来检验粘结剂的熔体流动行为。固化剂主要在纯粘结剂夹层中显著影响lef间距，而在镀铝粘结剂夹层中，其影响可以忽略不计，因为铝颗粒的存在在一定程度上阻碍了流动。在微镀铝粘结剂夹层中，由于在燃烧表面有大量的Al颗粒堆积，中间层相对于层界面有明显的突出。在纳米镀铝粘结剂三明治的情况下，这种突出相对较小，因为纳米Al颗粒燃烧速度快，这使得气相火焰靠近燃烧表面，尽管Al的积累程度比前一种情况要大得多。这导致纳米铝化粘结剂三明治在压力范围内（<7 MPa）的燃烧速度明显快于其他两种情况，其中LEFs主要控制三明治的燃烧速度。
This study reports the effect of binder melt flow on the burning behaviour, specifically the burning rate controlling sites referred to as the leading edge flames (LEFs), of different types of sandwich propellants, namely, pure, micro-aluminized and nano-aluminized binder. The distance between the LEFs anchored over the lamina interface edges of sandwiches is measured from the combustion images captured under high spatio-temporal resolution. Similarly, the extent of binder melt flow is also measured from the quenched surfaces of sandwiches. The burning rate experiments are performed as well on sandwiches with different middle lamina contents and thicknesses at pressures of 2, 4 and 7 MPa. Two different curing agents are considered to examine the melt flow behaviour of the binder. The curing agent significantly influences the inter-LEF distance mainly in the case of pure binder sandwiches, however, its effect is negligible in aluminized binder sandwiches because of the presence of Al particles that impedes the flow to appreciable extent. Substantial protrusion of the middle lamina relative to the lamina interfaces is observed in micro-aluminized binder sandwiches due to significant accumulation of Al particles on the burning surface. In the case of nano-aluminized binder sandwiches, such protrusion is relatively marginal since nano-Al particles burn quickly, which enables the gas phase flame to locate close to the burning surface, although the extent of Al accumulation is considerably more than in the former case. This causes the nano-aluminized binder sandwiches as a whole to burn significantly faster than the other two cases in the pressure range (<7 MPa) where the LEFs predominantly control the sandwich burning rates.