First,the principle of the digital image holographic laser interferometer for diffusion measurement was introduced.An experimental apparatus used to measure diffusion coefficients based on the laser holographic interferometer was established.The digital image processing program is coded in MATLAB.The diffusion coefficient was determined by the analysis of digital holographic images using the theory of Fourier phase method.Then,the diffusion coefficients of 0.33 mol/L potassium chloride solution and carbon dioxide in water at 298.15 K were tested,and compared with the data published in literature to prove the accuracy of the test apparatus.The deviation between the experimental results and reported values is 1.64％ and 2.29％,which can verify the exactitude of the experiment.Finally,the diffusion coefficient of carbon dioxide in RP-3 jet fuel was measured at 278.15-323.15 K with an interval of 5 K.The result shows that the diffusion coefficient rises with the increase of the temperature,and the Arrhenius function can be adopted to express the relationship among the diffusion coefficients at different temperatures.%首先,介绍了数字全息激光干涉测量实验原理,设计并搭建扩散系数测量实验平台,运用MATLAB软件编写数字图像处理程序,利用傅里叶相位分析方法进行数字全息图像分析,得到扩散系数解.然后,分别测量温度为298.15 K时0.33 mol/L的KC1溶液和CO2气体在水中扩散系数值并与文献研究数据进行对比,进行实验正确性验证,结果显示实验与文献标准值误差分别为1.63％和2.29％,满足实验要求.最后,运用此装置测试了278.15～323.15 K时CO2在RP 3航空燃油中的扩散系数随着温度升高扩散系数增大,并且不同温度下扩散系数值符合阿伦尼乌斯方程.
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