变温变压条件下硝基苯和硝基甲烷声速的实验研究

发布时间：2018-04-14 08:14

本文选题：声速 + 高温高压　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：声速是指声波在样品中的传输速度,是与材料的很多物理、化学特性密切相关的重要参数。测量声速的方法有多种,其中冲击受激光散射的方法结合了激光超声法和光散射法的特点,而且具有全光非接触式测量的优点。含能材料在高温高压下的声速与其冲击反应过程密切相关,一直是人们关注的焦点。本文选择两种典型的液相含能材料硝基苯和硝基甲烷为对象,研究其内部声速的温度压力响应行为。本文首先分析了不同声速测量方法的适用性和优缺点,并从中择取冲击受激光散射方法作为测量高温高压液体材料声速的方法,这种非接触式测量方法具有较小的衍射角度,可以在光路中置入限域高压装置,适宜高温高压下极端条件下的声速观测。选取灵敏度比较高的零差探测方法来放大实验信号,选取IR780染料来增大泵浦光(800 nm)的吸光度。进而改进了原有的冲击受激光散射实验装置,使其适应高温和高压实验条件的需求。首先测量了硝基苯和硝基甲烷常温常压下的声速值,测量结果与理论值符合得相当好证明了实验系统的可靠性。在此基础上又观测了常压变温和常温变压条件下两种样品中的声速,探究了样品中声速的变化规律。实验表明,升温和升压对硝基苯和硝基甲烷中的声速的作用是相反的,声速随着温度的升高线性减慢,随着压力的升高非线性加快。最后,结合上述研究,设计适合同时加温加压的实验装置,观测了高温高压共同作用条件下硝基苯和硝基甲烷的声速,分析了声速随温度和压力的变化关系,利用单独变温变压的声速响应函数模拟了高温高压同时作用下的声速实验数据,区分温度和压力对样品声速的贡献。模拟结果表明,在本文的温度和压力范围内,高温高压共同作用引起的硝基苯和硝基甲烷中声速的变化量可以用高温、高压单独作用下的声速变化量的线性叠加来表示。本文首次利用全光非接触的冲击受激光散射方法观测了变温变压条件下典型液相含能材料硝基苯和硝基甲烷中的声速,为研究材料的冲击响应特性提供了重要的信息。
[Abstract]:Sound velocity refers to the speed of sound wave transmission in a sample, and is an important parameter closely related to the physical and chemical properties of materials.There are many methods for measuring sound velocity, among which the method of shock and laser scattering combines the characteristics of laser ultrasonic method and light scattering method, and has the advantages of all-optical non-contact measurement.The sound velocity of energetic materials under high temperature and high pressure is closely related to its impact reaction process and has been the focus of attention.In this paper, two typical liquid phase energetic materials, nitrobenzene and nitromethane, were selected to study the temperature and pressure response behavior of the internal sound velocity.In this paper, the applicability, merits and demerits of different sound velocity measurement methods are analyzed, and the shock laser scattering method is chosen as the method to measure the sound velocity of high temperature and high pressure liquid materials. This non-contact measurement method has a small diffraction angle.A limiting high pressure device can be placed in the optical path, which is suitable for the observation of sound velocity under extreme conditions under high temperature and high pressure.The sensitive homodyne detection method is selected to amplify the experimental signal and the IR780 dye is selected to increase the absorbance of pump light.Furthermore, the original laser scattering experimental device is improved to meet the requirements of high temperature and high pressure experiments.The sound velocities of nitrobenzene and nitromethane were measured at room temperature and atmospheric pressure, and the experimental results were in good agreement with the theoretical values. The reliability of the experimental system was proved.On the basis of this, the sound velocities in two kinds of samples were observed under the condition of atmospheric pressure change and normal temperature variation, and the variation law of sound velocity in the samples was explored.The experimental results show that the effect of heating and increasing pressure on the sound velocity in nitrobenzene and nitromethane is opposite. The velocity of sound decreases linearly with the increase of temperature and accelerates with the increase of pressure.Finally, combined with the above research, an experimental device suitable for simultaneous heating and pressurization was designed to observe the sound velocity of nitrobenzene and nitromethane under the combined action of high temperature and high pressure, and to analyze the relationship between the sound velocity and temperature and pressure.The experimental data of sound velocity under high temperature and high pressure are simulated by using a single variable temperature and pressure response function to distinguish the contribution of temperature and pressure to the sound velocity of the sample.The simulation results show that in the range of temperature and pressure in this paper, the variation of sound velocity in nitrobenzene and nitromethane caused by the interaction of high temperature and high pressure can be expressed by the linear superposition of the variation of sound velocity under the action of high temperature and high pressure alone.In this paper, the acoustic velocities in nitrobenzene and nitromethane, a typical liquid phase energetic material, were observed by all-optical non-contact shock laser scattering method for the first time, which provides important information for studying the shock response characteristics of the materials.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN249;TB52

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