Eur. Phys. J. E (2015) 38: 29
https://doi.org/10.1140/epje/i2015-15029-0

Regular Article

Contribution to the benchmark for ternary mixtures: Measurement of diffusion and Soret coefficients in 1,2,3,4-tetrahydronaphthalene, isobutylbenzene, and dodecane onboard the ISS

¹ Institute of Continuous Media Mechanics, UB RAS, Koroleva St. 1, 614013, Perm, Russia
² Institute of Computational Modelling, SB RAS, Akademgorodok, 660036, Krasnoyarsk, Russia

^* e-mail: lubimova@psu.ru

Received: 1 August 2014
Revised: 27 September 2014
Accepted: 17 February 2015
Published online: 28 April 2015

Abstract

The paper is devoted to processing the data of DCMIX 1 space experiment. In this experiment, the Optical digital interferometry was used to measure the diffusion and Soret coefficients in the ternary mixture of 1,2,3,4-tetrahydronaphthalene, isobutylbenzene and n-dodecane at mass fractions of 0.8/0.1/0.1 and at 25°C. The raw interferometric images were processed to obtain the temporal and spatial evolution of refractive indices for two laser beams of different wavelengths. The method for extracting the diffusion and thermal diffusion coefficients originally developed for optical beam deflection was extended to optical digital interferometry allowing for the spatial variation of refractive index along the diffusion path. The method was validated and applied to processing the data for Soret and diffusion steps in 5 experimental runs. The obtained results for the Soret coefficients and one of the eigenvalues of diffusion matrix showed acceptable agreement within each step. The second eigenvalue was not determined with sufficient accuracy.