Development simultaneous of a simultaneous measurement system of temperature and concentration fields and effect of double-diffusive convection on crystallization

为了阐明热对流和溶质对流共存系统中产生双扩散对流的机理，开展了He-Ne激光全息干涉(HI)与Ar激光诱导荧光(LIF)相结合的温度和浓度场同时测量系统的基础研究。首先，将HI应用于双扩散对流，并尝试从干涉条纹计算局部浓度，利用干涉条纹与反射率轮廓线吻合，温度和浓度均影响反射率。S的结果是，利用干涉条纹和测量的局部温度，确定了准稳态下给定时刻的局部浓度。由干涉条纹得到的浓度是合适的，根据上述结果，当得到一个温度场时，就可以预测一个浓度场。因此，为了开发获得温度场的技术，利用激光诱导荧光对液体中的温度场进行了可视化。通过对荧光图像的三刺激值(RGB)的分析，发现卷轴亮度的变化与温度呈线性关系。利用该关系式可以实现激光诱导荧光图像的量化，对温度和浓度稳定的体系进行浓度场测量时，误差为±5%。

In order to illustrate the mechanism of double-diffusive convection generated in the system with which heat convection and solutal convection coexist, a basic study was performed to develop a simultaneous measurement system of temperature and concentration fields using He-Ne laser holographic interferometry (HI) in combination with Ar laser-induced fluorescence (LIF).First, HI was applied to the double-diffusive convection and calculation of local concentration was tried from the interference fringes obtained Following facts were employed that interference fringe agree with contour lines of reflective index, and that both temperature and concentration influence reflective index. As s result, local concentrations at given times in a quasi-steady state were determined using interference fringe and measured local temperatures. The concentration obtained from interference fringes was appropriate.From the above-mentioned result, when a temperature field is obtained, a concentration field can be predicted. Therefore, for the purpose of development of techniques obtaining the temperature field, the visualization of temperature field in a liquid phase using LIF was performed. Through the analysis of the tristimulus values (RGB) of the fluorescence image, it was found that the change in the brightness of reel is linear with temperature. The quantification of LIF images became possible by using this relation.When the concentration field was measured for the system with stable temperature and concentration, it was measurable with ±5% of error.