CONCENTRATION PROFILE OF HIGH INERTIA PARTICLES AT LARGE REYNOLDS NUMBER WALL TURBULENCE

• Main Author: Dmitriy F. Sikovsky
• Format: Article
• Language: Russian
• Published: Tomsk Polytechnic University 2019-11-01
• Series: Известия Томского политехнического университета: Инжиниринг георесурсов
• Subjects: turbulence; particle-laden flows; turbophoresis; statistical modeling; langevin model
• Online Access: http://izvestiya.tpu.ru/archive/article/view/2354/2106

The relevance of the discussed issue is caused by the numerous applications of turbulent gas-dispersed flows in many technical devices used in extraction of minerals, in the technologies of transportation of natural resources, energy and other industries. As an example, technologies and installations for pneumatic transport of powdered materials, tunnels of underground excavations, ventilation ducts for various types of rooms, gas cleaning systems, etc. can be cited. Flows with suspended particles are also widespread in nature and are objects of research in meteorology, geomorphology, hydraulics of river sediments, etc. The interaction of inertial particles with inhomogeneous near-wall turbulent flows is a very complex phenomenon that requires detailed modeling based on a deep understanding of mechanisms of particle interaction with multiscale turbulent vortex structures. The aim of the study is modeling of space distribution and statistical parameters of the motion of high inertial particles in the near-wall zone of a turbulent flow at large Reynolds numbers based on a stochastic Lagrangian model of fluid turbulence. Methods: Monte Carlo statistical simulation of particle motion based on the stochastic Lagrangian model of fluid turbulence and the scaling theory for wall turbulence. Results. Stochastic Lagrangian modeling of the dynamics of high inertia particles in the logarithmic layer of near-wall turbulence for large Reynolds numbers showed a significant non-equilibrium statistics of the particle velocity near the wall. It was shown that near the wall there is an accumulation of particles caused by turbophoresis, because of which the concentration of particles on the wall is more than three times higher than their concentration in the bulk of the flow provided the elastic rebound of particles from the wall. The intensity of the fluctuations of wall-normal particle velocity is not zero on the wall and is about 1/3 of the intensity of the fluctuations of wall-normal particle velocity in the bulk of the flow.