基于多光谱法测量等离子体场温度的算法研究

发布时间：2018-01-15 02:17

本文关键词：基于多光谱法测量等离子体场温度的算法研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：20世纪70年代以来,随着全球经济迅速崛起,在航天、国防、材料、能源等各领域中,针对高温等离子体场温度测量的要求越来越高。该类型温度场通常具有温度极高、过程瞬态、测温精度要求高、环境不稳定(存在测试环境恶劣、强电磁、振动等因素)的特点,目前国内外常用的包括接触式与非接触式测温方法不能同时满足以上测温需求。多光谱测温法凭借其属于非介入诊断技术且对于均匀或非均匀高温等离子体场都能精确诊断的特点受到国内外学者广泛运用。本文将基于多光谱测温法,提出一种能精确计算得到目标光谱发射效率的算法。该方法能真实提高多光谱测温法的测温精度,从而解决国防、工业等相关领域中对高温等离子体场温度大量程、高精度的测量需求。多光谱辐射测温法中存在光谱发射率ε这一参数,实际目标的光谱发射率表现复杂且与诸多因素相关。因此,如何高精度地获取目标光谱发射率成为了多光谱辐射测温研究中的关键难点。国内外学者提出了量热法、反射法、能量法来解决光谱发射率测量问题,但这些方法都有各自局限性且普适性不强。本文针对该问题,提出一种被测材料在不同温度下光谱发射率基函数不变的理论方法,即发射率基函数不变法。通过该方法,发射率模型可以根据物体在不同温度状态下,函数系数动态改变从而实现发射效率的自适应变化,得到最符合实际情况的发射率,提高整个辐射温度的测量精度。本文通过该方法建立了一套新的辐射测温数学模型,减少了光谱发射率对测温精度的影响,最终提高辐射温度的测量精度。通过对金属钨的仿真验证了算法精度能够达到0.66%。为了验证本文提出的算法有效性,研制了一台原理性瞬态测温样机系统。该系统的工作波长为400～700nm,特征谱线中心波长的定位精度为1nm,特征谱线的提取带宽小于6nm,响应速度小于1us,能对军事、国防、工业等领域中常用元素(铜、铝、镁、镍、钛、钨、铁)实现高精度辐射温度测量。通过瞬态测温样机系统,利用文章中提出的测温算法,对溴钨灯的温度场进行测温实验,同时也对强激光作用金属靶面的高温等离子体场进行温度测量实验。通过两次原理性验证实验,验证了本文算法在实际应用中的精确度以及可靠性。
[Abstract]:Since 1970s, with the rapid rise of the global economy, in space, national defense, materials, energy and other fields. The requirement of temperature measurement in high temperature plasma field is more and more high. This kind of temperature field usually has extremely high temperature, transient process, high precision of temperature measurement, unstable environment (bad test environment, strong electromagnetic). The characteristics of vibration and other factors. At present, both contact and non-contact temperature measurement methods used at home and abroad can not meet the above requirements. Multispectral thermometry is a non-interventional diagnostic technique and can not be used in homogeneous or non-uniform high temperature plasma fields. The characteristics of accurate diagnosis are widely used by domestic and foreign scholars. This paper will be based on multi-spectral temperature measurement method. This paper presents an algorithm which can accurately calculate the spectral emission efficiency of the target. This method can improve the temperature measurement accuracy of the multispectral temperature measurement method and solve the problem of national defense. In industry and other related fields, there is a demand for a large range of high temperature range and high precision measurement of high temperature plasma field. There is a parameter of spectral emissivity 蔚 in multispectral radiation thermometry. The spectral emissivity of the actual target is complex and related to many factors. How to obtain the target spectral emissivity with high accuracy has become a key difficulty in the study of multi-spectral radiation temperature measurement. Domestic and foreign scholars have proposed calorimetric method, reflection method and energy method to solve the problem of spectral emissivity measurement. However, these methods have their own limitations and their universality is not strong. In order to solve this problem, a theoretical method of invariant spectral emissivity basis function of measured materials at different temperatures is proposed in this paper. By this method, the emissivity model can change dynamically according to the object at different temperature state, so as to realize the adaptive change of the emissivity efficiency. The emissivity is the most suitable to the actual situation, and the measurement accuracy of the whole radiation temperature is improved. A new mathematical model of radiation temperature measurement is established by this method, which reduces the influence of spectral emissivity on the temperature measurement accuracy. Finally, the measurement accuracy of radiation temperature is improved. The simulation of tungsten metal shows that the accuracy of the algorithm can reach 0.66. In order to verify the effectiveness of the algorithm proposed in this paper. A principle transient temperature measuring prototype system is developed. The operating wavelength of the system is 400 ~ 700 nm, the location accuracy of the center wavelength of the characteristic spectral line is 1 nm, and the extraction bandwidth of the characteristic spectral line is less than 6 nm. The response speed is less than 1 us. it can realize high precision radiation temperature measurement for common elements (copper, aluminum, magnesium, nickel, titanium, tungsten and iron) in military, national defense and industrial fields. Using the temperature measurement algorithm proposed in this paper, the temperature field of the bromine tungsten lamp and the high temperature plasma field of the metal target are also measured. The accuracy and reliability of this algorithm in practical application are verified.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O53

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