2D-Measurement Technique for Simultaneous Quantitative Determination of Mixing Ratio and Velocity Field in Microfluidic Applications

Abstract. In this chapter, a framework will be presented for measuring and modeling transport processes using novel visualization techniques and extended optical flow techniques for digital image sequence analysis. In this way, parameters besides the 2-D xy velocity components can be extracted concurrently from the acquired 2-D image sequences, such as wall shear rates and momentum transport close to boundaries, diffusion coefficients, and depth z in addition to the z velocity components. Depending on the application, particularly the temporal regularization can be enhanced, leading to stabilization of results and reduction of spatial regularization. This is frequently of high importance for flows close to boundaries. Results from applications will be presented from the fields of environmental and life sciences as well as from engineering.

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“…For most data points, the ground truth value is well within the error bar. An in depth description of this application is presented in [3].…”

Section: Molecular Tagging Velocimetrymentioning

confidence: 99%

Spatiotemporal Image Analysis for Fluid Flow Measurements

Garbe

Kondermann

Jehle

et al. 2009

Notes on Numerical Fluid Mechanics and Multidisciplinary Design

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“…Raman-based determination of concentration gradients of mixing solvents is of fundamental importance in the field of fuel cell research, especially in the case of methanol and water (Deabate et al 2008). One of the first investigations using the Raman imaging mode applied to a model of a multi-lamination mixer was pursued in our group by Beushausen et al (2009).…”

Section: Introductionmentioning

confidence: 99%

Combined measurement of concentration distribution and velocity field of two components in a micromixing process

Wellhausen

Rinke²,

Wackerbarth

2011

Microfluid Nanofluid

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A lot of production processes involve mixing steps. The understanding of fluid flows in mixing processes of liquid components is needed in order to develop appropriate mixers for the chemical and pharmaceutical industry. Especially mixing in microfluidic systems is a challenge due to the diffusion-based processes. A multilamination micromixer with chessboard outlet geometry is used to induce the mixing process. To get comprehensive information about the mixing process, the velocity profile of the fluid flow and the species concentration distribution during the mixing process should be measured. Thus, we have combined particle image velocimetry (PIV) and Raman scattering. To enable rapid detection, the Raman imaging mode is used to visualise the concentration distribution. By this setup light sheets along and orthogonal to the outlet of the micromixer are recorded and synchronized with PIV measurement. As a model system we have used water and ethanol/methanol, enabling a selective monitoring of the substances by choosing appropriate spectral areas. The PIV is recorded based on Mie scattering and fluorescence using microsphere tracers. In this study, we present a setup for determination of the velocity profile field and the spatial concentration distribution of water and ethanol/methanol in a micromixer.

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