TY - GEN
T1 - Time-resolved velocity measurements in a matched refractive index facility of randomly packed spheres
AU - Kappes, Ethan
AU - King, Stephen
AU - Marciniak, Mateusz
AU - Nguyen, Thien D.
AU - Mills, Andrew
AU - Hassan, Yassin A.
AU - Muyshondt, Robert
AU - Ugaz, Victor
N1 - Publisher Copyright:
Copyright © 2018 ASME
PY - 2018
Y1 - 2018
N2 - Complex geometries and randomly connected void spaces within packed beds have hindered efforts to characterize the underlying transport phenomena occurring within. In this communication, we present our experimental studies on a facility of randomly packed spheres that can be a representative of sections within a reactor core in a nuclear power plant. The results of high-fidelity velocity measurements can be seen using Time-Resolved Particle Image Velocimetry (TR-PIV) at the pore scales and near the wall boundary in the Matched Index of Refraction (MIR) facility. The MIR approach allows for a noninvasive analysis of the flow within packed spheres at the microscopic scales with high temporal and spatial resolution. Flow characteristics obtained from the TR-PIV measurements at various Reynolds numbers are presented. The results include the first- and second-order flow statistics, such as mean velocity, root-mean-square fluctuating velocity and Reynolds stresses. Effects of the wall boundary and Reynolds numbers on flow patterns are currently being investigated. Comparisons of the mean velocities, root-mean-square fluctuating velocities, and Reynolds stress components show the increase of flow mixing and turbulent intensities within the gaps between spheres in the packed bed. Sizes of recirculation regions, however, seem to be independent of the increase of Reynolds numbers.
AB - Complex geometries and randomly connected void spaces within packed beds have hindered efforts to characterize the underlying transport phenomena occurring within. In this communication, we present our experimental studies on a facility of randomly packed spheres that can be a representative of sections within a reactor core in a nuclear power plant. The results of high-fidelity velocity measurements can be seen using Time-Resolved Particle Image Velocimetry (TR-PIV) at the pore scales and near the wall boundary in the Matched Index of Refraction (MIR) facility. The MIR approach allows for a noninvasive analysis of the flow within packed spheres at the microscopic scales with high temporal and spatial resolution. Flow characteristics obtained from the TR-PIV measurements at various Reynolds numbers are presented. The results include the first- and second-order flow statistics, such as mean velocity, root-mean-square fluctuating velocity and Reynolds stresses. Effects of the wall boundary and Reynolds numbers on flow patterns are currently being investigated. Comparisons of the mean velocities, root-mean-square fluctuating velocities, and Reynolds stress components show the increase of flow mixing and turbulent intensities within the gaps between spheres in the packed bed. Sizes of recirculation regions, however, seem to be independent of the increase of Reynolds numbers.
KW - Matched Index of Refraction
KW - Randomly Packed Spheres
KW - Time-Resolved Particle Image Velocimetry
UR - http://www.scopus.com/inward/record.url?scp=85056151557&partnerID=8YFLogxK
U2 - 10.1115/ICONE26-82425
DO - 10.1115/ICONE26-82425
M3 - Conference contribution
AN - SCOPUS:85056151557
T3 - International Conference on Nuclear Engineering, Proceedings, ICONE
BT - Thermal-Hydraulics and Safety Analyses
PB - American Society of Mechanical Engineers (ASME)
T2 - 2018 26th International Conference on Nuclear Engineering, ICONE 2018
Y2 - 22 July 2018 through 26 July 2018
ER -