气液两相介质中激光支持爆轰波的理论研究

发布时间：2018-05-09 10:20

本文选题：激光推进 + 激光支持爆轰波　；参考：《浙江大学》2015年硕士论文

【摘要】：气液两相介质激光推进具有较好的综合推进性能,逐渐引起了国内外学者的关注,其能量转换主要由激光支持爆轰波来实现。因此,对气液两相介质中的激光支持爆轰波进行研究具有重要意义。本文首先以单颗粒水滴为研究对象,结合水滴米散射模型和介质击穿的电子速密度方程,建立了单水滴激光击穿模型,阐明了入射激光功率密度、水滴半径和入射激光波长对击穿特性的影响；其次,结合气体介质激光支持爆轰波模型和云雾爆轰模型,建立了气液两相介质的激光支持爆轰波模型,研究了爆轰波前后主要参数的变化特征；最后,将气液两相介质的激光支持爆轰波模型应用于激光推进过程,建立了气液两相介质激光推进的理想动力循环模型,分析了能量转换效率的影响因素。研究结果表明,冲压比和定容增压比是影响能量转换效率的主要因素,增大冲压比或定容增压比都能有效提高能量转换效率,冲压比随进口马赫数的增大而增大,而定容增压比随入射激光功率密度或介质中水滴所占质量比的增大而增大。增大介质中水滴所占质量比能够有效增大定容增压比,提高能量转换效率。据算例可得,当冲压比π=10、水滴与空气的质量比由户0增大到f=10时,能量转换效率由ηt=52.5%提高到了ηt=55.8%。
[Abstract]:The gas-liquid two-phase medium laser propulsion has good comprehensive propulsion performance and has gradually attracted the attention of scholars at home and abroad. The energy conversion is mainly realized by laser supported detonation wave. Therefore, it is of great significance to study the laser-supported detonation wave in gas-liquid two-phase medium. In this paper, the single droplet laser breakdown model is established by combining the water drop scattering model and the electron velocity density equation of dielectric breakdown, and the incident laser power density is clarified. The influence of water drop radius and incident laser wavelength on the breakdown characteristics is also discussed. Secondly, the laser-supported detonation wave model in gas-liquid two-phase medium is established by combining the laser-supported detonation wave model and cloud detonation model in gas-liquid two-phase medium. The variation characteristics of the main parameters before and after detonation wave are studied. Finally, the laser supported detonation wave model of gas-liquid two-phase medium is applied to the laser propulsion process, and the ideal dynamic cycle model of gas-liquid two-phase medium laser propulsion is established. The influence factors of energy conversion efficiency are analyzed. The results show that the stamping ratio and the constant volumetric booster ratio are the main factors affecting the energy conversion efficiency. Increasing the stamping ratio or the constant volume booster ratio can effectively improve the energy conversion efficiency, and the stamping ratio increases with the increase of Mach number. The constant volumetric booster ratio increases with the increase of the power density of the incident laser or the mass ratio of water droplets in the medium. Increasing the mass ratio of water droplets in the medium can effectively increase the constant volumetric booster ratio and improve the energy conversion efficiency. As an example, the mass ratio of water droplet to air increases from 0 to f = 10:00, and the energy conversion efficiency increases from 52.5% to 55.8%.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN249;O359.1

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