聚乙烯在高速冲压推进动能弹中的燃烧特性数值模拟

Numerical Simulation Investigation on Combustion Characteristic of Polyethylene in High-speed Ramjet Kinetic Energy Projectile

为了研究聚乙烯在高速冲压推进动能弹中的燃烧特性,进行了高速冲压推进动能弹全弹一体化流场的数值模拟研究,分析了冲压发动机工作和非工作时流动特性差异,以及冲压发动机工作时聚乙烯的燃烧和推进特性。结果表明,冲压发动机工作时,燃烧室内压力均匀,中心轴线平均压力约为2.1MPa。随着轴向距离x的增大,火焰锋面先靠近固体燃料表面后逐渐远离。在再附着点之前,随着轴向距离x的增大,固体燃料的表面温度与燃面退移速率均持续增大,在再附着点附近达到最大值,然后不断减小。在本研究设计的气动构型下,高速冲压推进动能弹产生的额定推力、净推力分别为250N和76N,基于燃料的比冲为10593m·s^(-1)。

To research on the combustion characteristic of polyethylene in high-speed ramjet kinetic energy projectile,the numerical simulation investigation on the integrated flow field of high-speed ramjet kinetic energy projectile was carried out.The difference of flow characteristics when ramjet working or no working was analyzed.Both the combustion and propulsive performance characteristics of polyethylene when ramjet working were analyzed.The results show that when the ramjet is working,the pressure in combustion chamber is uniform and the average pressure of the central axis is about 2.1MPa.With increasing the axial distance x,the flame front closes to solid fuel surface at first,and then gradually keeps away from solid fuel surface.With increasing the axial distance x,both the surface temperature and regression rate of solid fuel continue to increase before re-attachment point,the maximum value is reached at the re-attachment point and then decrease.Under the aerodynamic configuration designed in this study,the nominal thrust,net thrust and specific impulse based on fuel produced by high-speed ramjet kinetic energy projectile are 250 N,76Nand 10593m·s^-1,respectively.