TY - JOUR
T1 - Effect of inter-particle spacing on turbulence modulation by Lagrangian PIV
AU - Sato, Yohei
AU - Fukuichi, Ushio
AU - Hishida, Koichi
N1 - Funding Information:
The authors would like to thank undergraduate student, Mr. N. Sekiya for performing the experiments and Dr. A. Tokuhiro at Japan Nuclear Cycle Development Institute for his suggestions. The work was subsidized by the Grant-in-Aid for the Japanese Ministry of Education, Science and Culture (No. 08405019).
PY - 2000/10
Y1 - 2000/10
N2 - Turbulence modulation by solid particles in a fully developed channel flow was investigated by Lagrangian measurement technique. Digital particle image velocimetry (DPIV) and a high-speed CCD camera mounted on a shuttle moving with particle mean streamwise velocity were used to simultaneously detect particle and fluid information among particles. Two classes of particles at particle volumetric fraction up to 3.32 x 10-4 were employed to provide characteristic values of length ratio and distance between particles, i.e., inter-particle spacing. Turbulence augmentation by particles greater than the Kolmogorov micro-length-scale was induced by a region of high strain rate and high vorticity located on both sides of the particles. The rapid distortion theory (RDT) applied to dispersed two-phase turbulent flows substantiates the observed directional non-isotropic structure with an increase in particle volumetric fraction. The enstrophy production was enhanced with decreasing values of inter-particle spacing, yielding an increase in the enstrophy among particles. (C) 2000 Begell House Inc. Published by Elsevier Science Inc. All rights reserved.
AB - Turbulence modulation by solid particles in a fully developed channel flow was investigated by Lagrangian measurement technique. Digital particle image velocimetry (DPIV) and a high-speed CCD camera mounted on a shuttle moving with particle mean streamwise velocity were used to simultaneously detect particle and fluid information among particles. Two classes of particles at particle volumetric fraction up to 3.32 x 10-4 were employed to provide characteristic values of length ratio and distance between particles, i.e., inter-particle spacing. Turbulence augmentation by particles greater than the Kolmogorov micro-length-scale was induced by a region of high strain rate and high vorticity located on both sides of the particles. The rapid distortion theory (RDT) applied to dispersed two-phase turbulent flows substantiates the observed directional non-isotropic structure with an increase in particle volumetric fraction. The enstrophy production was enhanced with decreasing values of inter-particle spacing, yielding an increase in the enstrophy among particles. (C) 2000 Begell House Inc. Published by Elsevier Science Inc. All rights reserved.
KW - Directional interaction
KW - Dispersed two-phase flows
KW - Inter-particle spacing
KW - Lagrangian PIV
KW - RDT
KW - Turbulence distortion
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U2 - 10.1016/S0142-727X(00)00044-8
DO - 10.1016/S0142-727X(00)00044-8
M3 - Article
AN - SCOPUS:0034306826
SN - 0142-727X
VL - 21
SP - 554
EP - 561
JO - International Journal of Heat and Fluid Flow
JF - International Journal of Heat and Fluid Flow
IS - 5
ER -