Electrolyte Magnetohydrondyamics Flow Sensing in an Open Annular Channel—A Vision System for Validation of the Mathematical Model

Abstract

Magnetohydrodynamics (MHD) is becoming more popular every day among developers of applications based on microfluidics, such as “lab on a chip” (LOC) and/or “micro-total analysis systems” (micro-TAS). Its physical properties enable fluid manipulation for tasks such as pumping, networking, propelling, stirring, mixing, and even cooling without the need for mechanical components, and its non-intrusive nature provides a solution to mechanical systems issues. However, these are not easy tasks. They all require precise flow control, which depends on several parameters, like microfluidics conductivity, the microfluidics conduit (channel) shape and size configuration, and the interaction between magnetic and electric fields. This results in a mathematical model that needs to be validated theoretically and experimentally. The present paper introduces the design of a 3D laminar flow involving an electrolyte in an annular open channel driven by a Lorentz force. For an organized description, first of all is provided an introduction to MHD applied in microfluidics, then an overall description of the proposed MHD microfluidic system is given, after that is focused in the theoretical validation of the mathematical model, next is described the experimental validation of the mathematical model using a customized vision system, and finally conclusions and future work are stated.

Automatic and Efficient Metallic Surface Defect Detection Based on Key Pixel Point Locations

“…1. Specifically, the procedure followed is the next: 1) The CMOS camera consists of four parameters, that is, the pixel size matrix is 3072*2048, framerate is 17 fps , exposure time is in the [27 2.5 ] ss  ， , and the pixel size is 2.4 m  ; 2) The lens model is MVL-HF1628M-6MP; 3) Considering the illumination uniformity, LED (Light-Emitting Diode) is best for our study and the placement angle is 45° (Note that the dark field illumination technique can also be applied effectively, such as the 3D laminar flow-based method in [33]); 4) The image acquisition card model is MV-8808 because of its excellent compatibility; 5) The external trigger system includes I / O (Input/Output), motion control, level conversion unit, etc. A Flow-chart of the proposed system is shown in Fig.2, this framework is described as follows: 1) The framework consists of five parts, that is, input defect images, data preprocessing, edge detection, defects location, and output results; 2) The raw images with different defects are as the input; 3) For data preprocessing, four types of noises can be eliminated effectively, including common noises and special noises; 4) To detect the edge of metal components, both Laplacian-based edge detector and Gaussian-based Laplacian method are proven to perform well; 5) Surface defects location is the key technology in this proposed system, and its basic idea is to mine incremental properties and parallel properties; 6) Finally, detection results can be outputted, including the types of defects, recognition accuracy, the size of defects, and the coordinates of defects.…”

Estimación de la incertidumbre en un sistema de visión para la evaluación experimental de un mezclador magneto-hidrodinámico

“…Se sabe que los sistemas de visión permiten modelar el comportamiento de micro-fluidos en sistemas mecánicos manipulados por MHD a través del trazado de partículas (Kavitha & Sathiaseelan, 2017), por tal razón, se procedió al diseño de un sistema de visión con los requerimientos necesarios para poder medir el flujo en el mezclador MHD propuesto. Con este propósito se inició una línea de investigación para el diseño de un sistema de visión apoyado en el análisis de los campos de velocidad presentes en un micro-fluido a partir del trazado de partículas, y a través del procesamiento digital, basado en un análisis de velocimetría de partículas en las imágenes (PIV, de sus singlas en inglés), cuya metodología de diseño se describe en Valenzuela et al (2018a). A continuación se resumen brevemente sus componentes y configuración para dar lugar al análisis de la estimación de su incertidumbre.…”

Magnetohydrodynamic velocity profile measurement for microelectromechanical systems micro-robot design

“…After the technique for 2-D velocity profile enhancement has been defined and ran through a standard experiment taken from the study by Valenzuela-Delgado et al, 17 new experimentation has been designed and performed to validate the output performance of the proposed technique. One hundred milliliters of distilled water was seeded with 0.1 g of S-HGS particles to fill the MHD stirrer, the electrodes were connected to a power supply and power on at the same time that the camera recorder with 0.5 V Figure 13.…”

“…Figure 3. 2-D velocity profile comparison of simulation and measurement results from experiment C described in Table1of publication 17. .…”