Regensburg 2019 – wissenschaftliches Programm
CPP 25.2: Poster
Dienstag, 2. April 2019, 14:00–16:00, Poster B1
Measurement of transport processes in multicomponent liquids by multi-color techniques — •Marcel Schraml, Pascal Möckel, Felix Sommer, and Werner Köhler — Department of Physics, University of Bayreuth, 95447 Bayreuth
Diffusive flows in a non-isothermal multicomponent fluid are characterized by complex cross-coupling phenomena between all concentration and temperature gradients. Since the number of unknown coefficients increases quadratically with the number of components, such multicomponent systems quickly become intractable, and today’s research focuses mainly on ternary mixtures as multicomponent model systems.
Within the ESA/Roscosmos DCMIX program, measurements are performed both under microgravity conditions aboard the International Space Station ISS and in various laboratories on ground. In order to resolve all components, optical multicolor beam deflection and interferometry experiments are typically employed. The most critical step in the data analysis is the transformation from the multicolor refractive index space to the compositions, for which the so-called contrast factor matrix must be inverted. Since this matrix is frequently ill-conditioned, extremely precise measurements of the partial derivatives of the refractive index with respect to the composition variables and the temperature are required.
In our poster we will present the optical multi-color techniques employed both on ground and in space and discuss consistent multicolor measurements of the optical contrast factors.