Diffusion coefficient analysis method using data statistical processing to reduce interference fringe noise effects

• Published in: AIChE journal Vol. 68; no. 3
• Main Authors: Tominaga, Kohji, Orikasa, Isamu, Tomaru, Momoko, Osada, Takuma, Hashimoto, Yoshitaka, Inatomi, Yuko, Suzuki, Shinsuke
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.03.2022; American Institute of Chemical Engineers
• Subjects: Concentration gradient; Diffusion; Diffusion coefficient; Field of view; Finite difference method; Interference fringes; Mathematical analysis; microgravity experiment; Noise reduction; phase analysis; Soret effect; Statistical analysis; Statistics; Visual field
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.17497

We proposed a simple statistical analysis method of minute concentration changes for measuring diffusion coefficient with reduced interference fringe noise effect. In the “Soret‐Facet Mission,” the one‐dimensional diffusion equation discretized by the finite difference method was applied for temporal homogenization processes of the minute concentration gradient induced by the Soret effect with random noises. Measured diffusion coefficient Dexp was determined by evaluating the obtained apparent diffusion coefficient distributions D. The measured value Dexp obtained by the proposed processes was found to be valid because the measured value Dexp was close to the theoretical one Dth calculated by the Darken equation and the reference one Dref calculated in” Facet Mission” in the same solution system, respectively. In addition, by analyzing about 1/16th of the total field of view, it was possible to obtain a diffusion coefficient that are more than 95% convergent for the measured value Dexp obtained from the full field of view analysis.