Experimental study of turbulent thermal diffusion of particles in inhomogeneous and anisotropic turbulence
Open Access
- 1 May 2022
- journal article
- research article
- Published by AIP Publishing in Physics of Fluids
- Vol. 34 (5), 055125
- https://doi.org/10.1063/5.0088982
Abstract
We experimentally studied the turbulent thermal diffusion of small particles in inhomogeneous and anisotropic stably stratified turbulence produced by one oscillating grid in the air flow. The velocity fields have been measured using Particle Image Velocimetry (PIV). We have determined various turbulence characteristics: the mean and turbulent velocities, two-point correlation functions of the velocity field, and an integral scale of turbulence from the measured velocity fields. The temperature field has been measured with a temperature probe equipped with 12 E thermocouples. Spatial distributions of micrometer-sized particles have been determined by a PIV system using the effect of the Mie light scattering by particles in the flow. The experiments have demonstrated that particles are accumulated at the minimum of mean fluid temperature due to the phenomenon of turbulent thermal diffusion. Using measured spatial distributions of particles and temperature fields, we have determined the effective turbulent thermal diffusion coefficient of particles in inhomogeneous temperature-stratified turbulence. This experimental study has clearly detected the phenomenon of turbulent thermal diffusion in inhomogeneous turbulence.Funding Information
- Israel Ministry of Science and Technology (3-16516)
This publication has 48 references indexed in Scilit:
- Tangling clustering instability for small particles in temperature stratified turbulencePhysics of Fluids, 2013
- Effect of large-scale coherent structures on turbulent convectionPhysical Review E, 2009
- Lagrangian Properties of Particles in TurbulenceAnnual Review of Fluid Mechanics, 2009
- Clustering instability of the spatial distribution of inertial particles in turbulent flowsPhysical Review E, 2002
- Mean-field theory for a passive scalar advected by a turbulent velocity field with a random renewal timePhysical Review E, 2001
- Measurement of turbulence near shear-free density interfacesJournal of Fluid Mechanics, 1997
- Turbulent Thermal Diffusion of Small Inertial ParticlesPhysical Review Letters, 1996
- Particle-Imaging Techniques for Experimental Fluid MechanicsAnnual Review of Fluid Mechanics, 1991
- The influence of molecular diffusivity on turbulent entrainment across a density interfaceJournal of Fluid Mechanics, 1968
- Stochastic Problems in Physics and AstronomyReviews of Modern Physics, 1943