【作者】 魏晓云；

【导师】 杨涛； 方锡惠； 高守美；

【作者基本信息】 国防科学技术大学 ， 航天工程， 2010， 硕士

【摘要】 本论文是以某固体火箭发动机静止试验压强曲线2.2s出现的异常峰值为研究背景,通过对该点火发动机和主发动机的内弹道数字仿真以及流场计算,展开对发动机点火异常的问题分析、故障定位、改进设计、改进验证试验。本文的研究内容涵盖以下四部分:为了判断某固体火箭发动机首次点火试验的内弹道压强曲线及性能是否正常,要求该发动机和点火发动机进行内弹道仿真。首先展开该点火发动机的设计方案,具体包括:点火发动机的总体参数设计、点火药柱的优化设计、点火发动机壳体的工程设计及有限元法强度校核、点火药盒的设计等;运用固体火箭发动机内弹道性能数字仿真软件,采用零维内弹道数学模型,得出该点火发动机内弹道仿真曲线。然后对该发动机点火启动过程进行内弹道仿真,仍采用零维内弹道数学模型,运用固体火箭发动机内弹道性能数字仿真软件,将点火药柱燃气生成量叠加到主装药燃气生成量上;将主装药简化成二维燃烧,采用Fluent动网格技术,进行发动机瞬态内流场计算,得出某时刻的流场速度、压强、温度、马赫数结果,分析发动机中燃气工作过程及内弹道性能。接着根据该发动机点火启动内弹道仿真结果,判定该发动机点火试验的内弹道曲线出现异常压强峰。经过分析排查,确定异常原因是喷管喉部被点火发动机未烧熔壳体堵塞引起的,影响发动机的点火可靠性,必须采取措施改进。最后介绍了该发动机点火发动机的改进设计,主要是点火发动机壳体结构的优化,后续点火试验验证了改进措施有效。至此,圆满完成某型固体火箭发动机的点火设计及优化。通过对该发动机点火试验内弹道压强曲线异常的分析和点火发动机的优化设计,得出:一体化球头结构的点火发动机能有效地避免点火时未完全烧熔的球头堵塞喷管喉部而出现的压强骤升问题;该结构尤其适用于装药短、喉径小的固体火箭发动机,可广泛应用在大、中、小型发动机上,能有效提高发动机的点火可靠性。更多还原

【Abstract】 Analyzing the anomalism peak appeared at 2.2 second on the pressure curve during a solid rocket motor being tested is taken as background in this paper. Through inner ballistic digital emulation and fluent calculation to the ignition motor and the main motor, we can analyze anomalism problem of the motor ignition test, determine failure, improve designation and do validation test.There are four parts as below included in this report:In order to judge whether a solid rocket motor inner ballistic pressure curve and performance is normal or not during first ignition test, it’s required to emulate inner ballistic of the motor and the ignition motor. At first, the ignition motor designation is developed, which includes: general parameters of ignition motor, optimization of ignition grain, experimental designation and finite member intension check of ignition motor shell, ignition case designation and etc. Applying solid rocket motor inner ballistic performance digital emulation software and Zero-Dimension inner ballistic mathematics model, we can get the ignition motor ballistic emulation curve.Then inner ballistic of the motor ignition and start up is emulated, while still applying Zero-Dimension inner ballistic mathematics model and using solid rocket motor inner ballistic performance digital emulation software, and adding up the ignition grain gas to the main motor grain gas. Simplifying the main motor grain to Tow-Dimension burning, using Fluent motive grid technology, we can do motor instant inner flow calculation, get flow velocity, pressure, temperature and mach number at one time, and analyze motor work process and inner ballistic performance.According to the inner ballistic emulation result of the motor ignition and start up, we judge that there is anomalism pressure peak in the motor ignition test ballistic curve. After analysis and exclusion, the reason is that the nozzle throat is jammed by not melt ignition motor shell. It will influence motor ignition reliability, we must improve it.Finally improvements on this ignition motor are introduced, mainly about ignition motor shell optimization. Later validation test proves those are effective.From now on, the solid rocket motor ignition designation is brought to success perfectly.Through this study about design and optimization of ignition motor, we get: the integral global head ignition motor can effectively resolve the anomalous peak value of pressure because the nozzle throat is jammed by not melted global seal cover after ignition motor works, which is applicable in all kinds of solid rocket motors, especially those whose grain length is short and nozzle diameter is small, and improve ignition reliability.更多还原