固体冲压发动机补燃室内含硼推进剂的燃烧及结构优化
发布时间：2018-07-23 09:47
【摘要】：本文研究了固体冲压发动机补燃室内含硼推进剂的燃烧,并对补燃室结构进行了优化。其中包括利用Ansys Workbench完成参数化建模,并编制程序探究了单个硼颗粒的点火过程。对Fluent进行了二次开发,研究了补燃室内含硼推进剂的两相流燃烧,并利用参数化建模对补燃室结构进行了优化。气相结果表明：补燃室头部存在高温回流区,而中心轴线附近温度较低。燃料入口处存在大的涡旋结构,空气入口处存在较小的涡旋结构。对单个硼颗粒点火的研究表明：减小颗粒初始半径、减小初始氧化层厚度、增加环境温度、增加环境中氧气与水蒸气的摩尔分数会缩短点火时间。颗粒初始半径、环境温度、水蒸气的摩尔分数在一定范围内将显著影响点火时间,超出一定范围后对点火时间的影响出现“边际效应”。点火时间随着初始氧化层厚度增加而线性增加,增加氧气摩尔分数对缩短点火时间的作用不明显。对含硼推进剂在补燃室内两相燃烧的研究表明：补燃室轴线附近颗粒点火较慢。燃料与空气接触面附近颗粒点火较快。颗粒在点火位置附近迅速融化为液态。补燃室中心轴线附近氧气浓度较低,颗粒的燃烧较慢。增加颗粒的初始直径,点火位置基本不变,颗粒燃烧效率显著降低。增加颗粒初始氧化层厚度,点火位置明显后移,颗粒燃烧效率略微下降。基于参数化建模的补燃室结构优化表明：参数化建模可快速得到补燃室优化结构,从而提高硼颗粒燃烧效率。
[Abstract]:In this paper, the combustion of boron propellant in the afterburner of solid ramjet is studied, and the structure of the combustor is optimized. The parameterized modeling is completed by using Ansys Workbench, and the ignition process of single boron particle is studied by programming. The secondary development of fluent was carried out, and the two-phase flow combustion of boron-containing propellant in the reburning chamber was studied, and the structure of the reburning chamber was optimized by parameterized modeling. The gas phase results show that there is a high temperature reflux zone at the head of the combustor, while the temperature near the center axis is low. There is a large vortex structure at the fuel entrance and a smaller vortex structure at the air entrance. The results show that the ignition time can be shortened by decreasing the initial radius of boron particles, decreasing the thickness of the initial oxide layer, increasing the ambient temperature and increasing the mole fraction of oxygen and water vapor in the environment. The initial radius of particles, ambient temperature and mole fraction of water vapor will significantly affect the ignition time in a certain range, and beyond a certain range, the influence on the ignition time will have a "marginal effect". The ignition time increases linearly with the increase of the initial oxide thickness, but the effect of increasing the oxygen molar fraction on the ignition time is not obvious. The two-phase combustion of boron containing propellants in the reburning chamber shows that the ignition of particles near the axis of the reburning chamber is slow. Particles near the interface between fuel and air ignite quickly. The particles melt rapidly into liquid near the ignition position. The concentration of oxygen near the central axis of the combustor is lower and the combustion of particles is slower. When the initial diameter of the particle is increased, the ignition position is almost unchanged, and the combustion efficiency of the particle decreases significantly. When the initial oxide layer thickness is increased, the ignition position is obviously moved backward, and the combustion efficiency of the particles decreases slightly. The structural optimization of the secondary combustion chamber based on parametric modeling shows that the optimized structure of the secondary combustion chamber can be obtained quickly by parameterized modeling, thus improving the combustion efficiency of boron particles.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK401
本文编号：2139013
[Abstract]:In this paper, the combustion of boron propellant in the afterburner of solid ramjet is studied, and the structure of the combustor is optimized. The parameterized modeling is completed by using Ansys Workbench, and the ignition process of single boron particle is studied by programming. The secondary development of fluent was carried out, and the two-phase flow combustion of boron-containing propellant in the reburning chamber was studied, and the structure of the reburning chamber was optimized by parameterized modeling. The gas phase results show that there is a high temperature reflux zone at the head of the combustor, while the temperature near the center axis is low. There is a large vortex structure at the fuel entrance and a smaller vortex structure at the air entrance. The results show that the ignition time can be shortened by decreasing the initial radius of boron particles, decreasing the thickness of the initial oxide layer, increasing the ambient temperature and increasing the mole fraction of oxygen and water vapor in the environment. The initial radius of particles, ambient temperature and mole fraction of water vapor will significantly affect the ignition time in a certain range, and beyond a certain range, the influence on the ignition time will have a "marginal effect". The ignition time increases linearly with the increase of the initial oxide thickness, but the effect of increasing the oxygen molar fraction on the ignition time is not obvious. The two-phase combustion of boron containing propellants in the reburning chamber shows that the ignition of particles near the axis of the reburning chamber is slow. Particles near the interface between fuel and air ignite quickly. The particles melt rapidly into liquid near the ignition position. The concentration of oxygen near the central axis of the combustor is lower and the combustion of particles is slower. When the initial diameter of the particle is increased, the ignition position is almost unchanged, and the combustion efficiency of the particle decreases significantly. When the initial oxide layer thickness is increased, the ignition position is obviously moved backward, and the combustion efficiency of the particles decreases slightly. The structural optimization of the secondary combustion chamber based on parametric modeling shows that the optimized structure of the secondary combustion chamber can be obtained quickly by parameterized modeling, thus improving the combustion efficiency of boron particles.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK401
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