Particle Tracking Experiments in Match‐Index‐Refraction Porous Media

Abstract

A low-cost, noninvasive, three-dimensional (3D), particle tracking velocimetry system was designed and built to investigate particle movement in match-index-refraction porous media. Both a uniform load of the glass beads of the same diameter and a binary load of the glass beads of two diameters were used. The purpose of the experiments is to study the effect of the two loads on the trajectories, velocity distribution, and spreading of small physical particles. A total of 35 particles were released and tracked in the uniform load and 46 in the binary load. The 3D trajectory of each particle was recorded with two video camcorders and analyzed. It is found that the particle's velocity, trajectory, and spreading are very sensitive to its initial location and that the smaller pore size or heterogeneity in the binary load increases the particles' velocity and enhances their spreading as compared with the uniform load. The experiments also verified the previous finding that the distribution of the particle velocities are lognormal in the longitudinal direction and Gaussian in two transverse directions and that the particle spreading is much larger along the longitudinal direction than along the traverse directions.

Measurements of Transitional and Turbulent Flow in a Randomly Packed Bed of Spheres with Particle Image Velocimetry

“…With PTV each seeding particle is traced and a Lagrangian flow field is obtained that contains less information about each point in the field as compared to PIV. As example of results with PTV Northrup et al (1993) found evidence of inter pore mixing within porous media at Re p < 1; PIV measurements in (Patil and Liburdy 2013) yield that at Re p ≈ 4 the spatial velocity variance increase when comparing the center plane data versus using data across the entire bed and Lachhab et al (2008) showed with PTV that velocity has a lognormal distribution in space for Re p < 1 and Stephenson and Stewart (1986) found that the latter velocity reaches its global maximum and minimum at distances near 0.2 and 0.5 D p from the wall for 5 < Re p < 250.…”

“…However, optical techniques in porous media require all phases be transparent refractive index-matched (RIM) materials. This limits the range of materials that can be used but it still makes these techniques powerful for generic studies of the flow in porous beds with PTV (Johnston et al 1975;Stephenson and Stewart 1986;Saleh et al 1992;Northrup et al 1993;Peurrung et al 1995;Moroni et al 2001;Huang et al 2008;Lachhab et al 2008), PIV (Patil and Liburdy 2013) and Laser Doppler Anemometry (Yarlagadda and Yoganathan 1989). PIV require the flow to be seeded with a relatively large number of particles (Raffel 2007;Westerweel 1997).…”

Pore-Scale Flow Measurements at the Interface between a Sandy Layer and a Model Porous Medium: Application to Statistical Modeling of Contact Erosion

“…So, contact erosion is usually initiated in a Forchheimer flow regime where both viscous and inertial forces must be considered. Measurements of flow characteristics at pore-scale have been realized by Nuclear Magnetic Resonance methods (Lebon, 1996;Johns, 2000) and by Laser Doppler Velocimetry (Giese, 1998) or Particle Tracking Velocimetry in a refraction-index matched porous medium (Rashidi, 1996;Lachhab, 2008;Huang, 2008). Numerical simulations have also been carried out by Lattice Boltzmann method (Maier, 1999) and by direct resolution of Navier-Stokes equations (Magnico, 2003).…”

Transitional and Turbulent Flow in a Bed of Spheres as Measured with Stereoscopic Particle Image Velocimetry

“…The inner diameter of the tube is 50 mm, and all spheres have a diameter of 7 mm. Lachhab et al (2008) designed a PTV system and investigated particle motion in match-index-refraction porous media. One purpose with the experiments is to study the spreading of small particles.…”