激光起爆的数值模拟研究

发布时间：2018-03-10 16:07

本文选题：激光　切入点：数值模拟　出处：《安徽理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：激光起爆是一种新型的起爆技术。含能材料的激光起爆技术,在工程、科研、军事、医疗等领域都有着重要的应用价值和广阔的发展前景。激光起爆具有安全性、可靠性、精确性等优点。激光与含能材料的相互作用效应是激光火工品研发的基础与核心,已有学者在此方面进行大量的研究工作。激光对含能材料的点火起爆可以通过理论、实验和数值的方法进行研究。用理论方法研究激光作用含能材料的温度场,受限于求解区域的不规则几何形状、材料的各向异性及各项物理量参数的变化等因素。也无法通过精密物理实验测得炸药等含能材料内部温度场情况。因此,激光起爆的数值模拟研究在精密火工品设计中显得尤为关键。数值计算结果成为炸药温度场最全面可信的依据。国内外学者已经针对激光起爆的数值计算进行了详细的研究,发表了大量的相关文献。本文主要针对激光起爆的各影响因素展开数值模拟研究。主要研究内容如下： (a)建立二维Fourier热传导模型,用古典显式差分格式对二维模型进行数值计算； (b)使用C80微量热仪测定PETN炸药的比热随温度变化情况,并将其作为变参数代入数值模型中进行计算； (c)在二维Fourier热传导模型中加入激光光强分布、激光脉冲宽度、激光脉冲波形、炸药化学反应热、炸药活化能、炸药中的掺杂物等因素,并将炸药变比热函数离散化代入模型中,计算分析对激光点火的影响。； (d)对三维Fourier热传导模型的算法进行了推导； (e)在展望中对激光点火技术提出新的思路。设想通过在炸药中放置点火聚焦微型药包,并在药包外部涂覆高弹性模量、低密度、低导热率的包裹物质。减少能量的波导损失和点火过程散失,有效降低起爆能量阈值。得出对激光点火有显著影响的因素有：激光强度、激光光束半径、炸药中的掺杂物、炸药比热。得出激光强度越强、光束半径越小,脉冲宽度越宽,波形越接近矩形,炸药中掺杂物的吸光系数越大,比热越低,将越有利于激光对炸药的点火起爆的结论
[Abstract]:Laser initiation is a new type of initiation technology. Laser initiation of energetic materials has important application value and broad development prospect in engineering, scientific research, military, medical and other fields. The interaction effect between laser and energetic materials is the basis and core of laser pyrotechnics research and development. Many scholars have done a lot of research in this field. The ignition and detonation of energetic materials by laser can be studied by theoretical, experimental and numerical methods. The temperature field of energetic materials acting on laser is studied by theoretical method, which is limited to the irregular geometry of the solution region. The anisotropy of materials and the variation of physical parameters can not be used to measure the internal temperature field of energetic materials such as explosives through precise physical experiments. The numerical simulation of laser detonation is particularly important in the design of precision detonators. The numerical results become the most comprehensive and reliable basis for the temperature field of explosives. The domestic and foreign scholars have carried out a detailed study on the numerical calculation of laser initiation. A large number of related documents have been published. This paper focuses on the numerical simulation of the factors affecting laser detonation. The main contents of the study are as follows:. The 2-D Fourier heat conduction model is established and the classical explicit difference scheme is used to numerically calculate the two-dimensional model. The specific heat of PETN explosive is measured by C80 microcalorimeter and calculated as a variable parameter in the numerical model. The laser intensity distribution, laser pulse width, laser pulse waveform, explosive chemical reaction heat, explosive activation energy and doping in explosives are added to the two-dimensional Fourier heat conduction model, and the specific heat function of explosives is discretized into the model. Calculating and analyzing the influence of laser ignition. The algorithm of 3D Fourier heat conduction model is deduced. A new idea for laser igniting technology is put forward in this paper. It is envisaged that the charge can be coated with high modulus of elasticity and low density by setting fire in the explosive, focusing on the micro charge and coating it with high elastic modulus, low density, low density, high elastic modulus, low density, high elastic modulus and low density. The energy loss of waveguide and the loss of ignition process are reduced, and the threshold of initiation energy is reduced effectively. The factors that have significant influence on laser ignition are: laser intensity, laser beam radius, dopant in explosive, specific heat of explosive. It is concluded that the stronger the laser intensity, the smaller the beam radius, the wider the pulse width, and the closer the waveform is to the rectangle. The higher the absorbency coefficient and the lower the specific heat of explosives, the more favorable the conclusion is that the laser ignites the explosive.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD235.4

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