Particle Image Velocimetry with high power Light Emitting Diodes for flow through porous medium

Abstract

Particle Image Velocimetry (PIV) is a non-invasive optical measurement technique which has been used for many decades to measure fluid velocity. Conventionally, PIV systems are equipped with a laser system for illuminating the flow field. However, laser systems are expensive, and their usage usually creates specific safety precautions. In this work, we used a low cost LED based illumination system in conjunction with the refractive-index matching method to measure flow velocities in porous media. Hydro jelly beads were used as a transparent porous medium which have the same refractive index as water. The movement of tracer particles which were illuminated by the LED pulse was captured by a high-speed double pulsed camera and the resulting images were processed for receiving the pore-scale fluid velocity. Interstitial velocity vectors averaged over a specified region were presented and compared with the vertical velocity component calculated from the volumetric flow rate. In general, our results demonstrated the usability of LED based PIV system for investigating flow conditions in porous media. The future aim of this study is the investigation of micro-scale seepage induced internal erosion of granular structures.

Optimizing recording speed and interrogation window for rotating flow recorded in the ambient light: PIV analysis

“…In PIV analysis, significant technological advancement has provided alternatives for the high-tech equipment, e.g., high-power pulsed lasers can be replaced with high-power LEDs and high-speed professional cameras with smartphone cameras, which in turn makes the overall PIV system safe, simple, easy to operate, and notably economical (Kashyap et al;Buchmann et al 2010;Willert et al 2010;Harshani et al 2015;Hain et al 2016;Dai et al 2017;Aguirre-Pablo et al 2017). Tomographic PIV, 3D PIV, mIPIV, and smartPIV are a few examples of technological developments.…”

Destabilization of Immersed Dense Granular Material Submitted to Localized Fluidization: An Experimental and Numerical Study

“…A vertical laser sheet centered on the injection zone (s) illuminates the iso-index medium thus created. A possible replacement, of the laser system, which is expensive and cumbersome and for security problems, by LED lighting, has also been the subject of several studies in the past [14][15][16]. Moreover, some researchers have reported that hydrogel beads are also suitable as a solid phase for visualization through granular materials.…”