Abstract

FLORES-FUENTES, Wendy et al. Estimation of the uncertainty in a vision system for the experimental evaluation of a magneto-hydrodynamic mixer. Ing. invest. y tecnol. [online]. 2020, vol.21, n.4, 00005.  Epub Nov 20, 2020. ISSN 2594-0732.  https://doi.org/10.22201/fi.25940732e.2020.21.4.033.

The methodology and the result of the estimation of uncertainty of a vision system based on darkfield lighting for the experimental evaluation of a magneto-hydrodynamic mixer (MHD) are presented. The evaluation was realized through a vision system designed to perform velocity measurements on the free surface of the micro-fluid contained in the MHD mixer, said vision system allows to reduce the transparency restriction of the container walls (proposed mixer) and allows to apply its walls as a pair of distributed electrodes. The structure of the mixer is classified as an open annular channel. The channel is formed by two cylinders of conductive material, an insulating base, and an open surface. The annular channel contains a micro-fluid of low conductivity, which is governed by the Lorenz law, due to the presence of a magnetic field and an electric field, resulting in a mixing process. The manipulation of micro-fluids through the MHD is very useful and of great interest for the design of sophisticated micro-electromechanical systems (MEMS), especially for total microanalysis system (μTAS), known as lab-on-a-chip (LOC) devices. However, it is not an easy task, for precise control of the micro-fluid it is necessary to consider in the design of the mixers parameters such as the shape and size of the channel, conductivity of the micro-fluidic, and the interaction of the magnetic and electric fields. In addition, a tool is required to evaluate the behavior of the micro-fluid, on this time, a vision system based on particle image velocimetry (PIV), to which, under the experimentation specifications described in this work, a measurement uncertainty of ± 0.001152 m/s was estimated for measurement profiles with stable velocity behavior, whose maximum profile velocity is greater than 0.003000 m/s and correspond to low conductivity MHD fluids composed of 100 ml of distilled water and 0.1 g of S-HGS spheres induced by a magnetic field of 0.1624 T, an electric field induced by the application of a potential difference greater than 4.0 V in an open annular channel with 7 mm depth setting, radius ratio of 0.60, and aspect ratio of 0.22. With the vision system it will be possible to obtain a geometrically and magnetohydrodynamic optimized configuration of mixers that will open up new possibilities in the efficiency of automatic control of the fluid mixing process.

Keywords : Magneto-hydrodynamic; micro-fluid; vision system; mixer.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )