超声速弹丸底部边缘排气减阻机理及特性研究

According to problem of the lower increasing rate for base bleed projectile, that is related not yet fully cognition about drag reduction mechanism of base bleed. Therefore, a idea of new type of base bleed structure was proposed. The means of simulation-based and wind tunnel experiment complemented for verification were adopted, and the investigation on drag reduction mechanism and characteristics of base bleed projectile using edge base bleed in the supersonic was studied, which has some advanced and innovative. The secondary combustion of real base bleed gas was considered, and the comparative study of the similarities and differences between the center type and edge type was conducted. The effect of the structure of the base bleed, base bleed parameters, flight parameters, the structural parameters of projectile and environmental parameters on the flow field in the bottom of the supersonic projectile and the drag reduction characteristics was analyzed. The study results can provide a theoretical basis and technical reference for the design of the next generation of base bleed projectile, It also can enrich the connotation of the drag reduction mechanism and improve the raise awareness, which has important academic significance and value of military needs.

针对国内底排弹增程率较低问题，与尚未完全认知底排减阻机理有很大关系。为此，提出一种新的边缘型底部排气设想，采用数值模拟为主，辅以实验验证的研究手段，开展超声速弹丸底部边缘排气减阻机理及特性研究，具有一定的先进性和创新性，具体考虑真实药剂燃气二次燃烧效应，比较研究与中心型底部排气减阻机理的异同，重点分析排气结构、排气参数、飞行参数、弹结构参数、环境参数对超声速弹丸底部流场和减阻特性的影响规律。本项目研究成果可为我国新一代底部排气弹设计提供理论依据和技术参考，同时也对丰富底排减阻机理研究内涵和认知度提高具有重要的学术意义与军事需求价值。

项目针对一种新的边缘型底部排气的超声速弹丸，采用数值模拟的研究手段，研究其减阻机理及特性。具体考虑真实药剂燃气二次燃烧效应，比较研究与中心型底部排气减阻机理的异同，重点分析排气结构、排气参数、飞行参数和环境参数对超声速弹丸底部流场和减阻特性的影响规律。首先，建立了边缘型底部排气底排弹的底部流动与燃烧模型，以此研究底排真实燃气的底部流动、减阻机理与特性；其次，以此模型为基础，分别研究了底排真实燃气条件下底排流场结构与减阻机理、底排真实燃气发生时二次燃烧的主要区域和燃烧过程、来流马赫数对底部流场结构和底部压力分布的影响以及排气参数、排气面积、排气总温对底部流场结构和减阻特性的影响规律和机理；最后，开展来流攻角和弹体船尾角对底排真实燃气条件下的底部流场结构以及全弹气动特性影响研究，分析了底部流场结构与气动特性随来流攻角和弹体船尾角的变化规律。结果表明：边缘排气型底排弹的减阻性能优于原始的中心型底排弹；随着排气参数的增大，底压比先增大后减小，然后再增大；来流攻角对底部流场结构和全弹气动影响较大；不同海拔发射的底部排气弹在减阻阶段的排气参数均随着时间的增加而呈增大的趋势，但在减阻末阶段，变化趋势变缓；不同底排药柱燃速的底部排气弹在减阻阶段的排气参数均随时间的增加而呈先增大后减小的趋势；采用高燃速底排药柱的底部排气弹排气质量流率相对于低燃速的底部排气弹较大，但减阻效果并没有明显提高。这些结论能为底部排气理论与技术、底排弹相关的工程研制提供重要参考。